Mars Archives

September 5, 2015May 31, 2016 by Matt Williams

Solar System Guide

The Universe is a very big place, and we occupy a very small corner of it. Known as the Solar System, our stomping grounds are not only a tiny fraction of the Universe as we know it, but is also a very small part of our galactic neighborhood (aka. the Milky Way Galaxy). When it comes right down to it, our world is just a drop of water in an endless cosmic sea.

Nevertheless, the Solar System is still a very big place, and one which is filled with its fair share of mysteries. And in truth, it was only within the relatively recent past that we began to understand its true extent. And when it comes to exploring it, we’ve really only begun to scratch the surface.

Discovery:

With very few exceptions, few people or civilizations before the era of modern astronomy recognized the Solar System for what it was. In fact, the vast majority of astronomical systems posited that the Earth was a stationary object and that all known celestial objects revolved around it. In addition, they viewed it as being fundamentally different from other stellar objects, which they held to be ethereal or divine in nature.

Although there were some Greek, Arab and Asian astronomers during Antiquity and the Medieval period who believed that the universe was heliocentric in nature (i.e. that the Earth and other bodies revolved around the Sun) it was not until Nicolaus Copernicus developed his mathematically predictive model of a heliocentric system in the 16th century that it began to become widespread.

The first star party? Galileo shows of the sky in Saint Mark's square in Venice. Note the lack of adaptive optics. (Illustration in the Public Domain). — *Galileo (1564 – 1642) would often show people how to use his telescope to view the sky in Saint Mark’s square in Venice. Note the lack of adaptive optics. Credit: Public Domain*

During the 17th-century, scientists like Galileo Galilei, Johannes Kepler, and Isaac Newton developed an understanding of physics which led to the gradual acceptance that the Earth revolves round the Sun. The development of theories like gravity also led to the realization that the other planets are governed by the same physical laws as Earth.

The widespread use of the telescope also led to a revolution in astronomy. After Galileo discovered the moons of Jupiter in 1610, Christian Huygens would go on to discover that Saturn also had moons in 1655. In time, new planets would also be discovered (such as Uranus and Neptune), as well as comets (such as Halley’s Comet) and the Asteroids Belt.

By the 19th century, three observations made by three separate astronomers determined the true nature of the Solar System and its place the universe. The first was made in 1839 by German astronomer Friedrich Bessel, who successfully measured an apparent shift in the position of a star created by the Earth’s motion around the Sun (aka. stellar parallax). This not only confirmed the heliocentric model beyond a doubt, but revealed the vast distance between the Sun and the stars.

In 1859, Robert Bunsen and Gustav Kirchhoff (a German chemist and physicist) used the newly invented spectroscope to examined the spectral signature of the Sun. They discovered that it was composed of the same elements as existed on Earth, thus proving that Earth and the heavens were composed of the same elements.

With parallax technique, astronomers observe object at opposite ends of Earth's orbit around the Sun to precisely measure its distance. CREDIT: Alexandra Angelich, NRAO/AUI/NSF. — *With parallax technique, astronomers observe object at opposite ends of Earth’s orbit around the Sun to precisely measure its distance. Credit: Alexandra Angelich, NRAO/AUI/NSF.*

Then, Father Angelo Secchi – an Italian astronomer and director at the Pontifical Gregorian University – compared the spectral signature of the Sun with those of other stars, and found them to be virtually identical. This demonstrated conclusively that our Sun was composed of the same materials as every other star in the universe.

Further apparent discrepancies in the orbits of the outer planets led American astronomer Percival Lowell to conclude that yet another planet, which he referred to as “Planet X“, must lie beyond Neptune. After his death, his Lowell Observatory conducted a search that ultimately led to Clyde Tombaugh’s discovery of Pluto in 1930.

Also in 1992, astronomers David C. Jewitt of the University of Hawaii and Jane Luu of the MIT discovered the Trans-Neptunian Object (TNO) known as (15760) 1992 QB1. This would prove to be the first of a new population, known as the Kuiper Belt, which had already been predicted by astronomers to exist at the edge of the Solar System.

Further investigation of the Kuiper Belt by the turn of the century would lead to additional discoveries. The discovery of Eris and other “plutoids” by Mike Brown, Chad Trujillo, David Rabinowitz and other astronomers would lead to the Great Planet Debate – where IAU policy and the convention for designating planets would be contested.

Structure and Composition:

At the core of the Solar System lies the Sun (a G2 main-sequence star) which is then surrounded by four terrestrial planets (the Inner Planets), the main Asteroid Belt, four gas giants (the Outer Planets), a massive field of small bodies that extends from 30 AU to 50 AU from the Sun (the Kuiper Belt). The system is then surrounded a spherical cloud of icy planetesimals (the Oort Cloud) that is believed to extend to a distance of 100,000 AU from the Sun into the Interstellar Medium.

The Sun contains 99.86% of the system’s known mass, and its gravity dominates the entire system. Most large objects in orbit around the Sun lie near the plane of Earth’s orbit (the ecliptic) and most planets and bodies rotate around it in the same direction (counter-clockwise when viewed from above Earth’s north pole). The planets are very close to the ecliptic, whereas comets and Kuiper belt objects are frequently at greater angles to it.

It’s four largest orbiting bodies (the gas giants) account for 99% of the remaining mass, with Jupiter and Saturn together comprising more than 90%. The remaining objects of the Solar System (including the four terrestrial planets, the dwarf planets, moons, asteroids, and comets) together comprise less than 0.002% of the Solar System’s total mass.

Sun and Planets — *The Sun and planets to scale. Credit: Illustration by Judy Schmidt, texture maps by Björn Jónsson*

Astronomers sometimes informally divide this structure into separate regions. First, there is the Inner Solar System, which includes the four terrestrial planets and the Asteroid Belt. Beyond this, there’s the outer Solar System that includes the four gas giant planets. Meanwhile, there’s the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune (i.e. Trans-Neptunian Objects).

Most of the planets in the Solar System possess secondary systems of their own, being orbited by planetary objects called natural satellites (or moons). In the case of the four giant planets, there are also planetary rings – thin bands of tiny particles that orbit them in unison. Most of the largest natural satellites are in synchronous rotation, with one face permanently turned toward their parent.

The Sun, which comprises nearly all the matter in the Solar System, is composed of roughly 98% hydrogen and helium. The terrestrial planets of the Inner Solar System are composed primarily of silicate rock, iron and nickel. Beyond the Asteroid Belt, planets are composed mainly of gases (such as hydrogen, helium) and ices – like water, methane, ammonia, hydrogen sulfide and carbon dioxide.

Objects farther from the Sun are composed largely of materials with lower melting points. Icy substances comprise the majority of the satellites of the giant planets, as well as most of Uranus and Neptune (hence why they are sometimes referred to as “ice giants”) and the numerous small objects that lie beyond Neptune’s orbit.

Together, gases and ices are referred to as volatiles. The boundary in the Solar System beyond which those volatile substances could condense is known as the frost line, which lies roughly 5 AU from the Sun. Within the Kuiper Belt, objects and planetesimals are composed mainly of these materials and rock.

Formation and Evolution:

The Solar System formed 4.568 billion years ago from the gravitational collapse of a region within a large molecular cloud composed of hydrogen, helium, and small amounts of heavier elements fused by previous generations of stars. As the region that would become the Solar System (known as the pre-solar nebula) collapsed, conservation of angular momentum caused it to rotate faster.

The center, where most of the mass collected, became increasingly hotter than the surrounding disc. As the contracting nebula rotated faster, it began to flatten into a protoplanetary disc with a hot, dense protostar at the center. The planets formed by accretion from this disc, in which dust and gas gravitated together and coalesced to form ever larger bodies.

Due to their higher boiling points, only metals and silicates could exist in solid form closer to the Sun, and these would eventually form the terrestrial planets of Mercury, Venus, Earth, and Mars. Because metallic elements only comprised a very small fraction of the solar nebula, the terrestrial planets could not grow very large.

In contrast, the giant planets (Jupiter, Saturn, Uranus, and Neptune) formed beyond the point between the orbits of Mars and Jupiter where material is cool enough for volatile icy compounds to remain solid (i.e. the frost line).

The ices that formed these planets were more plentiful than the metals and silicates that formed the terrestrial inner planets, allowing them to grow massive enough to capture large atmospheres of hydrogen and helium. Leftover debris that never became planets congregated in regions such as the asteroid belt, Kuiper belt, and Oort cloud.

Within 50 million years, the pressure and density of hydrogen in the center of the protostar became great enough for it to begin thermonuclear fusion. The temperature, reaction rate, pressure, and density increased until hydrostatic equilibrium was achieved.

At this point, the Sun became a main-sequence star. Solar wind from the Sun created the heliosphere and swept away the remaining gas and dust from the protoplanetary disc into interstellar space, ending the planetary formation process.

*The terrestrial planets of our Solar System at approximately relative sizes. From left, Mercury, Venus, Earth and Mars. Credit: Lunar and Planetary Institute*

The Solar System will remain roughly as we know it today until the hydrogen in the core of the Sun has been entirely converted to helium. This will occur roughly 5 billion years from now and mark the end of the Sun’s main-sequence life. At this time, the core of the Sun will collapse, and the energy output will be much greater than at present.

The outer layers of the Sun will expand to roughly 260 times its current diameter, and the Sun will become a red giant. The expanding Sun is expected to vaporize Mercury and Venus and render Earth uninhabitable as the habitable zone moves out to the orbit of Mars. Eventually, the core will be hot enough for helium fusion and the Sun will burn helium for a time, after which nuclear reactions in the core will start to dwindle.

At this point, the Sun’s outer layers will move away into space, leaving a white dwarf – an extraordinarily dense object that will have half the original mass of the Sun, but will be the size of Earth. The ejected outer layers will form what is known as a planetary nebula, returning some of the material that formed the Sun to the interstellar medium.

Inner Solar System:

In the inner Solar System, we find the “Inner Planets” – Mercury, Venus, Earth, and Mars – which are so named because they orbit closest to the Sun. In addition to their proximity, these planets have a number of key differences that set them apart from planets elsewhere in the Solar System.

For starters, the inner planets are rocky and terrestrial, composed mostly of silicates and metals, whereas the outer planets are gas giants. The inner planets are also much more closely spaced than their outer Solar System counterparts. In fact, the radius of the entire region is less than the distance between the orbits of Jupiter and Saturn.

Generally, inner planets are smaller and denser than their counterparts, and have few to no moons or rings circling them. The outer planets, meanwhile, often have dozens of satellites and rings composed of particles of ice and rock.

The terrestrial inner planets are composed largely of refractory minerals such as the silicates, which form their crusts and mantles, and metals such as iron and nickel which form their cores. Three of the four inner planets (Venus, Earth and Mars) have atmospheres substantial enough to generate weather. All of them have impact craters and tectonic surface features as well, such as rift valleys and volcanoes.

Of the inner planets, Mercury is the closest to our Sun and the smallest of the terrestrial planets. Its magnetic field is only about 1% that of Earth’s, and it’s very thin atmosphere means that it is hot during the day (up to 430°C) and freezing at night (as low as -187 °C) because the atmosphere can neither keep heat in or out. It has no moons of its own and is comprised mostly of iron and nickel. Mercury is one of the densest planets in the Solar System.

Venus, which is about the same size as Earth, has a thick toxic atmosphere that traps heat, making it the hottest planet in the Solar System. This atmosphere is composed of 96% carbon dioxide, along with nitrogen and a few other gases. Dense clouds within Venus’ atmosphere are composed of sulphuric acid and other corrosive compounds, with very little water. Much of Venus’ surface is marked with volcanoes and deep canyons – the biggest of which is over 6400 km (4,000 mi) long.

Earth is the third inner planet and the one we know best. Of the four terrestrial planets, Earth is the largest, and the only one that currently has liquid water, which is necessary for life as we know it. Earth’s atmosphere protects the planet from dangerous radiation and helps keep valuable sunlight and warmth in, which is also essential for life to survive.

Like the other terrestrial planets, Earth has a rocky surface with mountains and canyons, and a heavy metal core. Earth’s atmosphere contains water vapor, which helps to moderate daily temperatures. Like Mercury, the Earth has an internal magnetic field. And our Moon, the only one we have, is comprised of a mixture of various rocks and minerals.

*Mars, as it appears today, Credit: NASA*

Mars is the fourth and final inner planet, and is also known as the “Red Planet” due to the oxidization of iron-rich materials that form the planet’s surface. Mars also has some of the most interesting terrain features of any of the terrestrial planets. These include the largest mountain in the Solar System (Olympus Mons) which rises some 21,229 m (69,649 ft) above the surface, and a giant canyon called Valles Marineris – which is 4000 km (2500 mi) long and reaches depths of up to 7 km (4 mi).

Much of Mars’ surface is very old and filled with craters, but there are geologically newer areas of the planet as well. At the Martian poles are polar ice caps that shrink in size during the Martian spring and summer. Mars is less dense than Earth and has a smaller magnetic field, which is indicative of a solid core, rather than a liquid one.

Mars’ thin atmosphere has led some astronomers to believe that the surface water that once existed there might have actually taken liquid form, but has since evaporated into space. The planet has two small moons called Phobos and Deimos.

Outer Solar System:

The outer planets (sometimes called Jovian planets or gas giants) are huge planets swaddled in gas that have rings and plenty of moons. Despite their size, only two of them are visible without telescopes: Jupiter and Saturn. Uranus and Neptune were the first planets discovered since antiquity, and showed astronomers that the solar system was bigger than previously thought.

*The outer planets of our Solar System at approximately relative sizes. From left, Jupiter, Saturn, Uranus and Neptune. Credit: Lunar and Planetary Institute*

Jupiter is the largest planet in our Solar System and spins very rapidly (10 Earth hours) relative to its orbit of the sun (12 Earth years). Its thick atmosphere is mostly made up of hydrogen and helium, perhaps surrounding a terrestrial core that is about Earth’s size. The planet has dozens of moons, some faint rings and a Great Red Spot – a raging storm that has happening for the past 400 years at least.

Saturn is best known for its prominent ring system – seven known rings with well-defined divisions and gaps between them. How the rings got there is one subject under investigation. It also has dozens of moons. Its atmosphere is mostly hydrogen and helium, and it also rotates quickly (10.7 Earth hours) relative to its time to circle the Sun (29 Earth years).

Uranus was first discovered by William Herschel in 1781. The planet’s day takes about 17 Earth hours and one orbit around the Sun takes 84 Earth years. Its mass contains water, methane, ammonia, hydrogen and helium surrounding a rocky core. It has dozens of moons and a faint ring system. The only spacecraft to visit this planet was the Voyager 2 spacecraft in 1986.

Neptune is a distant planet that contains water, ammmonia, methane, hydrogen and helium and a possible Earth-sized core. It has more than a dozen moons and six rings. NASA’s Voyager 2 spacecraft also visited this planet and its system by 1989 during its transit of the outer Solar System.

*How many moons are there in the Solar System? Image credit: NASA*

Trans-Neptunian Region:

There have been more than a thousand objects discovered in the Kuiper Belt, and it’s theorized that there are as many as 100,000 objects larger than 100 km in diameter. Given to their small size and extreme distance from Earth, the chemical makeup of KBOs is very difficult to determine.

However, spectrographic studies conducted of the region since its discovery have generally indicated that its members are primarily composed of ices: a mixture of light hydrocarbons (such as methane), ammonia, and water ice – a composition they share with comets. Initial studies also confirmed a broad range of colors among KBOs, ranging from neutral grey to deep red.

This suggests that their surfaces are composed of a wide range of compounds, from dirty ices to hydrocarbons. In 1996, Robert H. Brown et al. obtained spectroscopic data on the KBO 1993 SC, revealing its surface composition to be markedly similar to that of Pluto (as well as Neptune’s moon Triton) in that it possessed large amounts of methane ice.

Water ice has been detected in several KBOs, including 1996 TO₆₆, 38628 Huya and 20000 Varuna. In 2004, Mike Brown et al. determined the existence of crystalline water ice and ammonia hydrate on one of the largest known KBOs, 50000 Quaoar. Both of these substances would have been destroyed over the age of the Solar System, suggesting that Quaoar had been recently resurfaced, either by internal tectonic activity or by meteorite impacts.

Keeping Pluto company out in the Kuiper belt are many other objects worthy of mention. Quaoar, Makemake, Haumea, Orcus and Eris are all large icy bodies in the Belt and several of them even have moons of their own. These are all tremendously far away, and yet, very much within reach.

Oort Cloud and Farthest Regions:

The Oort Cloud is thought to extend from between 2,000 and 5,000 AU (0.03 and 0.08 ly) to as far as 50,000 AU (0.79 ly) from the Sun, though some estimates place the outer edge as far as 100,000 and 200,000 AU (1.58 and 3.16 ly). The Cloud is thought to be comprised of two regions – a spherical outer Oort Cloud of 20,000 – 50,000 AU (0.32 – 0.79 ly), and disc-shaped inner Oort (or Hills) Cloud of 2,000 – 20,000 AU (0.03 – 0.32 ly).

The outer Oort cloud may have trillions of objects larger than 1 km (0.62 mi), and billions that measure 20 kilometers (12 mi) in diameter. Its total mass is not known, but – assuming that Halley’s Comet is a typical representation of outer Oort Cloud objects – it has the combined mass of roughly 3×10²⁵ kilograms (6.6×10²⁵ pounds), or five Earths.

*The layout of the solar system, including the Oort Cloud, on a logarithmic scale. Credit: NASA*

Based on the analyses of past comets, the vast majority of Oort Cloud objects are composed of icy volatiles – such as water, methane, ethane, carbon monoxide, hydrogen cyanide, and ammonia. The appearance of asteroids thought to be originating from the Oort Cloud has also prompted theoretical research that suggests that the population consists of 1-2% asteroids.

Earlier estimates placed its mass up to 380 Earth masses, but improved knowledge of the size distribution of long-period comets has led to lower estimates. The mass of the inner Oort Cloud, meanwhile, has yet to be characterized. The contents of both Kuiper Belt and the Oort Cloud are known as Trans-Neptunian Objects (TNOs), because the objects of both regions have orbits that that are further from the Sun than Neptune’s orbit.

Exploration:

Our knowledge of the Solar System also benefited immensely from the advent of robotic spacecraft, satellites, and robotic landers. Beginning in the mid-20th century, in what was known as “The Space Age“, manned and robotic spacecraft began exploring planets, asteroids and comets in the Inner and Outer Solar System.

All planets in the Solar System have now been visited to varying degrees by spacecraft launched from Earth. Through these unmanned missions, humans have been able to get close-up photographs of all the planets. In the case of landers and rovers, tests have been performed on the soils and atmospheres of some.

The first artificial object sent into space was the Soviet satellite Sputnik 1, which was launched in space in 1957, successfully orbited the Earth for months, and collected information on the density of the upper atmosphere and the ionosphere. The American probe Explorer 6, launched in 1959, was the first satellite to capture images of the Earth from space.

Robotic spacecraft conducting flybys also revealed considerable information about the planet’s atmospheres, geological and surface features. The first successful probe to fly by another planet was the Soviet Luna 1 probe, which sped past the Moon in 1959. The Mariner program resulted in multiple successful planetary flybys, consisting of the Mariner 2 mission past Venus in 1962, the Mariner 4 mission past Mars in 1965, and the Mariner 10 mission past Mercury in 1974.

By the 1970’s, probes were being dispatched to the outer planets as well, beginning with the Pioneer 10 mission which flew past Jupiter in 1973 and the Pioneer 11 visit to Saturn in 1979. The Voyager probes performed a grand tour of the outer planets following their launch in 1977, with both probes passing Jupiter in 1979 and Saturn in 1980-1981. Voyager 2 then went on to make close approaches to Uranus in 1986 and Neptune in 1989.

Launched on January 19th, 2006, the New Horizons probe is the first man-made spacecraft to explore the Kuiper Belt. This unmanned mission flew by Pluto in July 2015. Should it prove feasible, the mission will also be extended to observe a number of other Kuiper Belt Objects (KBOs) in the coming years.

Orbiters, rovers, and landers began being deployed to other planets in the Solar System by the 1960’s. The first was the Soviet Luna 10 satellite, which was sent into lunar orbit in 1966. This was followed in 1971 with the deployment of the Mariner 9 space probe, which orbited Mars, and the Soviet Venera 9 which orbited Venus in 1975.

The Galileo probe became the first artificial satellite to orbit an outer planet when it reached Jupiter in 1995, followed by the Cassini–Huygens probe orbiting Saturn in 2004. Mercury and Vesta were explored by 2011 by the MESSENGER and Dawn probes, respectively, with Dawn establishing orbit around the asteroid/dwarf planet Ceres in 2015.

The first probe to land on another Solar System body was the Soviet Luna 2 probe, which impacted the Moon in 1959. Since then, probes have landed on or impacted on the surfaces of Venus in 1966 (Venera 3), Mars in 1971 (Mars 3 and Viking 1 in 1976), the asteroid 433 Eros in 2001 (NEAR Shoemaker), and Saturn’s moon Titan (Huygens) and the comet Tempel 1 (Deep Impact) in 2005.

Curiosity Rover snapped this self portrait mosaic with the MAHLI camera while sitting on flat sedimentary rocks at the “John Klein” outcrop where the robot conducted historic first sample drilling inside the Yellowknife Bay basin, on Feb. 8 (Sol 182) at lower left in front of rover. The photo mosaic was stitched from raw images snapped on Sol 177, or Feb 3, 2013, by the robotic arm camera - accounting for foreground camera distortion. Credit: NASA/JPL-Caltech/MSSS/Marco Di Lorenzo/KenKremer (kenkremer.com). — Curiosity Rover self portrait mosaic, taken with the MAHLI camera while sitting on flat sedimentary rocks at the “John Klein” outcrop in Feb. 2013. Credit: NASA/JPL-Caltech/MSSS/Marco Di Lorenzo/KenKremer

To date, only two worlds in the Solar System, the Moon and Mars, have been visited by mobile rovers. The first robotic rover to land on another planet was the Soviet Lunokhod 1, which landed on the Moon in 1970. The first to visit another planet was Sojourner, which traveled 500 meters across the surface of Mars in 1997, followed by Spirit (2004), Opportunity (2004), and Curiosity (2012).

Manned missions into space began in earnest in the 1950’s, and was a major focal point for both the United States and Soviet Union during the “Space Race“. For the Soviets, this took the form of the Vostok program, which involved sending manned space capsules into orbit.

The first mission – Vostok 1 – took place on April 12th, 1961, and was piloted by Soviet cosmonaut Yuri Gagarin (the first human being to go into space). On June 6th, 1963, the Soviets also sent the first woman – Valentina Tereshvoka – into space as part of the Vostok 6 mission.

In the US, Project Mercury was initiated with the same goal of placing a crewed capsule into orbit. On May 5th, 1961, astronaut Alan Shepard went into space aboard the Freedom 7 mission and became the first American (and second human) to go into space.

After the Vostok and Mercury programs were completed, the focus of both nations and space programs shifted towards the development of two and three-person spacecraft, as well as the development of long-duration spaceflights and extra-vehicular activity (EVA).

*Bootprint in the moon dust from Apollo 11. Credit: NASA*

This took the form of the Voshkod and Gemini programs in the Soviet Union and US, respectively. For the Soviets, this involved developing a two to three-person capsule, whereas the Gemini program focused on developing the support and expertise needed for an eventual manned mission to the Moon.

These latter efforts culminated on July 21st, 1969 with the Apollo 11 mission, when astronauts Neil Armstrong and Buzz Aldrin became the first men to walk on the Moon. As part of the Apollo program, five more Moon landings would take place through 1972, and the program itself resulted in many scientific packages being deployed on the Lunar surface, and samples of moon rocks being returned to Earth.

After the Moon Landing took place, the focus of the US and Soviet space programs then began to shift to the development of space stations and reusable spacecraft. For the Soviets, this resulted in the first crewed orbital space stations dedicated to scientific research and military reconnaissance – known as the Salyut and Almaz space stations.

The first orbital space station to host more than one crew was NASA’s Skylab, which successfully held three crews from 1973 to 1974. The first true human settlement in space was the Soviet space station Mir, which was continuously occupied for close to ten years, from 1989 to 1999. It was decommissioned in 2001, and its successor, the International Space Station, has maintained a continuous human presence in space since then.

*Space Shuttle Columbia launching on its maiden voyage on April 12th, 1981. Credit: NASA*

The United States’ Space Shuttle, which debuted in 1981, became the only reusable spacecraft to successfully make multiple orbital flights. The five shuttles that were built (Atlantis, Endeavour, Discovery, Challenger, Columbia and Enterprise) flew a total of 121 missions before being decommissioned in 2011.

During their history of service, two of the craft were destroyed in accidents. These included the Space Shuttle Challenger – which exploded upon take-off on Jan. 28th, 1986 – and the Space Shuttle Columbia which disintegrated during re-entry on Feb. 1st, 2003.

In 2004, then-U.S. President George W. Bush announced the Vision for Space Exploration, which called for a replacement for the aging Shuttle, a return to the Moon and, ultimately, a manned mission to Mars. These goals have since been maintained by the Obama administration, and now include plans for an Asteroid Redirect mission, where a robotic craft will tow an asteroid closer to Earth so a manned mission can be mounted to it.

All the information gained from manned and robotic missions about the geological phenomena of other planets – such as mountains and craters – as well as their seasonal, meteorological phenomena (i.e. clouds, dust storms and ice caps) have led to the realization that other planets experience much the same phenomena as Earth. In addition, it has also helped scientists to learn much about the history of the Solar System and its formation.

As our exploration of the Inner and Outer Solar System has improved and expanded, our conventions for categorizing planets has also changed. Our current model of the Solar System includes eight planets (four terrestrial, four gas giants), four dwarf planets, and a growing number of Trans-Neptunian Objects that have yet to be designated. It also contains and is surrounded by countless asteroids and planetesimals.

Given its sheer size, composition and complexity, researching our Solar System in full detail would take an entire lifetime. Obviously, no one has that kind of time to dedicate to the topic, so we have decided to compile the many articles we have about it here on Universe Today in one simple page of links for your convenience.

There are thousands of facts about the solar system in the links below. Enjoy your research.

The Solar System:

Theories about the Solar System:

Moons:

Anything EXTREME!:

Solar System Stuffs:

September 3, 2015February 24, 2017 by Fraser Cain

What Do Other Planets Sound Like?

We know that in space, no one can hear you scream. But what would things sound like on another planet?

When humans finally set foot on Mars, they’re going to be curious about everything around them.

What’s under that rock? What does it feel like to jump in the lower Martian gravity. What does Martian regolith taste like? What’s the bitcoin to red rock exchange rate?

As long as they perform their activities in the safety of a pressurized habitation module or exosuit, everything should be fine. But what does Mars sound like?

I urge all future Martian travelers, no matter how badly you want to know the answer to this question: don’t take your helmet off. With only 1% the atmospheric pressure of Earth, you’d empty your lungs with a final scream in a brief and foolish moment, then suffocate horribly with a mouthful of dust on the surface of the Red Planet.

But… actually, even the screaming would sound a little different. How different? Let me show you. First you just need to take your helmet off for a just a little sec, just an itsy bitsy second. Here, I’ll hold it for you. Oh, come on, just take your helmet off. All the cool kids are doing it.

What about Venus? Or Titan? What would everything sound like on an alien world?

We evolved to exist on Earth, and so it’s perfectly safe for us to listen to sounds in the air. No space suit needed. Unless you didn’t evolve on Earth, in which case I offer to serve as emissary to our all new alien overlords.

You know sounds travel when waves of energy propagate through a medium, like air or water. The molecules bump into each other and pass along the energy until they strike something that won’t move, like your ear drum. Then your brain turns bouncing into sounds.

The speed of the waves depends on what the medium is made of and how dense it is. For example, sound travels at about 340 meters/second in dry air, at sea level at room temperature. Sound moves much more quickly through liquid. In water it’s nearly 1,500 m/s. It’s even faster through a solid – iron is up past 5,100 m/s. Our brain perceives a different sound depending on the intensity of the waves and how quickly they bounce off our ears.

Artist's impression of the surface of Venus. Credit: ESA/AOES — Artist’s impression of the surface of Venus. Credit: ESA/AOES

Other worlds have media that sound waves can travel through, and with your eardrum exposed to the atmosphere you should theoretically hear sounds on other worlds. Catastrophic biological failures from using your eardrums outside of documented pressure tolerances notwithstanding.

Professor Tim Leighton and a team of researchers from the University of Southampton have simulated what we would hear standing on the surface of other worlds, like Mars, Venus or even Saturn’s Moon Titan.

On Venus, the pitch of your voice would become deeper, because vocal cords would vibrate much more slowly in the thicker Venusian atmosphere. But sounds would travel more quickly through the soupy atmosphere. According to Dr. Leighton, humans would sound like bass Smurfs. Mars would sound a little bit higher, and Titan would sound totally alien.

Dr. Leighton actually simulated the same sound on different worlds. Here’s the sound of thunder on Earth.
Here’s what it would sound like on Venus.
And here’s what it would sound like on Mars.
Here’s what a probe splashing into water on Earth would sound like.
And here’s what it would sound like splashing into a hydrocarbon lake on Titan.

You might be amazed to learn that we still haven’t actually recorded sounds on another world, right up until someone points out that putting a microphone on another planet hasn’t been that big a priority for any space mission.

A fish-eye view of Titan's surface from the European Space Agency's Huygens lander in January 2005. Credit: ESA/NASA/JPL/University of Arizona — A fish-eye view of Titan’s surface from the European Space Agency’s Huygens lander in January 2005. Credit: ESA/NASA/JPL/University of Arizona

Especially when we could analyze soil samples, but hey fart sounds played and then recorded in the Venusian atmosphere could prove incredibly valuable to the future of internet soundboards.

The Planetary Society has been working to get a microphone included on a mission. They actually included a microphone on the Mars Polar Lander mission that failed in 1999. Another French mission was going to have a microphone, but it was cancelled. There are no microphones on either Spirit or Opportunity, and the Curiosity Rover doesn’t have one either despite its totally bumping stereo.

Here’s is the only thing we’ve got. When NASA’s Phoenix Lander reached the Red Planet in 2008, it had a microphone on board to capture sounds. It recorded audio as it entered the atmosphere, but operators turned the instrument off before it reached the surface because they were worried it would interfere with the landing.

Here’s the recording.

Meh. I’m going to need you to do better NASA. I want an actual microphone recording winds on the surface of Mars. I hope it’s something Dethklok puts on their next album, they could afford that kind of expense.

It turns out, that if you travel to an alien world, not only would the sights be different, but the sounds would be alien too. Of course, you’d never know because you’re be too chicken to take your helmet off and take in the sounds through the superheated carbon dioxide or methane atmosphere.

What sounds would you like to hear on an alien world? Tell us in the comments below.

August 27, 2015February 24, 2017 by Fraser Cain

Are Martian Dust Storms Dangerous?

Just how dangerous are the terrifying dust storms that swarm Mars?

Brave explorers trek across the red dunes of Mars when a dangerous dust storm blows in. In moments, our astronauts are blasted by gale force winds and driving sand, reducing visibility to zero. The brave heroes stumble desperately through the driving onslaught, searching in vain for shelter from the catastrophic conditions. One is blown into a ravine, or right to the edge of the cliff, requiring a dramatic rescue and likely a terrible terrible sacrifice and important parting words showing the true mettle of our heroes.

“Tell my Asuka… printed body pillow… I loved her…”

Will they make it? Why the heck would anyone land on that dusty irradiated death trap? Actually, a better question might be “Why do writers lean so hard on this trope?”. I’m looking at you Andy Weir.

Martian dust storms don’t just come from the fevered imagination of the same sci-fi writer who gave us a lush Venusian jungle, Saturnalian lava flats and Moon floor cheese. These dust storms are all too real and they drive at serious windspeeds.

NASA’s Viking landers clocked them at 100 km/h during dust storm season. Which is a thing on Mars. The landers sheltered enough from the big storms that they probably didn’t experience the greatest winds they’re capable of.

Scientists have seen evidence that sand is shifted around on the surface of Mars, and the regolith requires high wind speeds to pick it up and shove it around. Dust devils spin up across the surface, and rotate at hurricane speeds.

When the wind is above 65 km/h, it’s fast enough to pick up dust particles and carry them into the atmosphere encasing the planet in a huge, swirling, shroud. Freaked out yet? Is this dangerous? It sure sounds dangerous.

Apologies to all the fearmongering sci-fi writers, but actually, it’s not that dangerous. Here’s why.

First off, you’re not on Mars. It’s a book. Second, it’s a totally different experience on Earth. Here when you feel the wind blasting you in the face, or watch it dismantle a house during a tornado, it’s the momentum of the air particles hammering into it.

An illustration of a dust storm on Mars. Credit: Brian Grimm and Nilton Renno

That momentum comes from air particle density and their velocity. Sadly, the density of the atmosphere on Mars is a delicate 1% of what we’re used to. It’s got the velocity, but it just doesn’t have the density.

It’s the difference between getting hit by a garden hose and a firehose with the same nozzle speed. One would gets you soaked, the other can push you down the street and give you bruises.

To feel a slight breeze on Mars similar to Earth, you multiply the wind speed by 10. So, if the wind was going about 15 km/h here, you’d need to be hit by winds going about 150 km/h there to have the same experience.

It’s not impossible for winds to go that fast on Mars, but that’s still not enough wind to fly a kite. To get it off the ground your mission buddy holds the kite, and you run around in the dumb Martian sand like a try-hard ass.

It would fly for a second and then crash down. You’d wonder why you even brought a kite to Mars in the first place because it’s NEVER windy enough.

Boo hoo. Your Mars kite doesn’t work. Good news! You’re on Mars!
Bad news. It was a one way trip. Good news! A wizard has made you immortal!
Bad news. The wizard has brought to life the entire fictional cast of the Twilight series and they’re also there and immortal. Have fun brooding with your new dorky friends, FOR ETERNITY.

What I’m saying is you could stand on the red planet restaurant patio and laugh at anything the weather system could throw at you. That is unless, you’re solar powered.

Mars gets regular dust storms. From time to time, they can get truly global. In 2001, a storm picked up enough dust to shroud the entire planet in a red haze. Temperatures went up as dust helped trap heat in the atmosphere. This storm lasted for 3 months before temperatures cooled, and the dust settled back down again.

During a storm in 2007, dust blocked 99% of the light reaching the solar panels of the Opportunity rover. This severely decreased the energy it had to power its instruments, and most importantly, the heaters. Ultimately, it was possible that the cold could kill the rover, if the dust hadn’t subsided quickly enough.

If you happen to see a movie or read a book about an astronaut on Mars dealing with a dangerous dust storm, don’t worry. They’ll be fine, the wind won’t shred them to pieces. Instead, focus on unbreathably thin atmosphere, the bone chilling cold, or the constant deadly radiation.

That and where’s their food come from again? Well, now you know dust storms aren’t a big issue. Want to travel to Mars? Tell us in the comments below.

If you haven’t checked it out yet, go read “The Martian”. Jay and I loved the pants off it and we can’t wait to see the film version.

August 20, 2015December 23, 2015 by Ken Kremer

Curiosity Snaps Stunning One of a Kind Belly Selfie At Buckskin Mountain Base Drill Site

This low-angle self-portrait of NASA’s Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called “Buckskin.” The MAHLI camera on Curiosity’s robotic arm took multiple images on Aug. 5, 2015, that were stitched together into this selfie. Credits: NASA/JPL-Caltech/MSSS
More selfie and drilling mosaics below[/caption]

NASA’s Curiosity rover has snapped a stunningly beautiful, one of a kind ‘belly selfie’ amidst the painstaking ‘Buckskin’ drill campaign at the Martian mountain base marking the third anniversary since her touchdown on the Red Planet.

The unique self portrait was taken from a low-angle for the first time and shows the six wheeled rover at work collecting her seventh drilled sample at the ‘Buckskin’ rock target earlier this month in the “Marias Pass” area of lower Mount Sharp.

‘Buckskin’ is also unique in a fabulously scientifically way because the rover discovered a new type of Martian rock that’s surprisingly rich in silica – and unlike any other targets found before.

The low camera angle is what enables the awesome Buckskin belly selfie. It’s a distinctively dramatic view and actually stitched from 92 images captured by the Mars Hand Lens Imager (MAHLI) on Aug. 5, 2015, or Sol 1065 of the mission.

The high resolution MAHLI color camera is located on the end of the 7 foot-long (2.1 meter-long) robotic arm.

This version of a self-portrait of NASA's Curiosity Mars rover at a drilling site called "Buckskin" is presented as a stereographic projection, which shows the horizon as a circle. The MAHLI camera on Curiosity's robotic arm took dozens of component images for this selfie on Aug. 5, 2015. Credits: NASA/JPL-Caltech/MSSS — This version of a self-portrait of NASA’s Curiosity Mars rover at a drilling site called “Buckskin” is presented as a stereographic projection, which shows the horizon as a circle. The MAHLI camera on Curiosity’s robotic arm took dozens of component images for this selfie on Aug. 5, 2015. Credits: NASA/JPL-Caltech/MSSS

Indeed the car-sized rover has taken spectacular selfies several times before during her three year long trek across the Martian surface, since the August 2012 landing inside Mars’ Gale Crater. But for those past selfies the MAHLI camera was hoisted higher to give the perspective of looking somewhat downward and showing the rovers top deck and trio of sample inlet ports.

In this case, the rover team specifically commanded Curiosity to position “the camera lower in relation to the rover body than for any previous full self-portrait of Curiosity,” said NASA officials.

Two patches of gray colored powdered rock material drilled from Buckskin are visible in the selfie scene, in front of the rover.

“The patch closer to the rover is where the sample-handling mechanism on Curiosity’s robotic arm dumped collected material that did not pass through a sieve in the mechanism. Sieved sample material was delivered to laboratory instruments inside the rover. The patch farther in front of the rover, roughly triangular in shape, shows where fresh tailings spread downhill from the drilling process.”

Prior selfies were taken at the “Rocknest” (http://photojournal.jpl.nasa.gov/catalog/PIA16468), “John Klein” (http://photojournal.jpl.nasa.gov/catalog/PIA16937), “Windjana” (http://photojournal.jpl.nasa.gov/catalog/PIA18390) and “Mojave” drill sites.

Basically in the Sol 1065 belly selfie at “Buckskin” we see the underbelly of the rover and all six wheels along with a complete self portrait.

On several prior occasions, MAHLI was used to image just the underbelly and wheels to aid in inspecting the wheels to look for signs of damage inflicted by sharp-edged Martian rocks poking holes in the aluminum wheels.

Underbelly view of Curiosity rover and wheels on Sol 34. Credit: NASA/JPL/MSSS/Ken Kremer/Marco Di Lorenzo — Underbelly view of Curiosity rover and wheels on Sol 34, Sept. 9, 2012. Credit: NASA/JPL/MSSS/Ken Kremer/Marco Di Lorenzo

Each wheel measures 20 inches (50 centimeters) in diameter and about 16 inches (40 centimeters) wide. And the MAHLI monitoring images have shown the effects of increasing wear and tear that ultimately forced the rover drivers to alter Curiosity’s driving route on the crater floor in favor of smoother and less rocky terrain imparting less damage to the critical wheels.

If you take a close look at the new selfie up top, you’ll see a small rock stuck onto Curiosity’s left middle wheel (on the right in this head-on view). The rock was seen also in prior wheel monitoring images taken three weeks ago.

“The selfie at Buckskin does not include the rover’s robotic arm beyond a portion of the upper arm held nearly vertical from the shoulder joint. With the wrist motions and turret rotations used in pointing the camera for the component images, the arm was positioned out of the shot in the frames or portions of frames used in this mosaic,” according to officials.

The drilling campaign into “Buckskin” was successfully conducted on Sol 1060 (July 30, 2015) at the bright toned “Lion” outcrop to a full depth of about 2.6 inches (6.5 centimeters) and approximately 1.6 cm (0.63 inch) diameter.

Curiosity extends robotic arm and conducts sample drilling at “Buckskin” rock target at bright toned “Lion” outcrop at the base of Mount Sharp on Mars, seen at right. Gale Crater eroded rim seen in the distant background at left, in this composite multisol mosaic of navcam raw images taken to Sol 1059, July 30, 2015. Navcam camera raw images stitched and colorized. Inset: MAHLI color camera up close image of full depth drill hole at “Buckskin” rock target on Sol 1060. Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/kenkremer.com/Marco Di Lorenzo

You can also see another perspective of the rover at work while reaching out with the robotic arm and drilling into ‘Buckskin’ as illustrated in our mosaics of mastcam and navcam camera raw images created by the image processing team of Ken Kremer and Marco Di Lorenzo.

The main bore hole was drilled next to the initial mini hole test and shows the indicative residue of grey colored tailings from the Martian subsurface seen distributed around the new hole.

Curiosity rover successfully drills into Martian outcrop at Buckskin rock target at current work site at base of Mount Sharp in August 2015, in this mosaic showing full depth drill hole and initial test hole, with grey colored subsurface tailings and mineral veins on surrounding Red Planet terrain. This high resolution photo mosaic is a multisol composite of color images taken by the mast mounted Mastcam-100 color camera up to Sol 1060, July 31, 2015. Credit: NASA/JPL-Caltech/Ken Kremer/kenkremer.com/Marco Di Lorenzo

Curiosity has now moved on from the “Marias Pass” area.

Curiosity recently celebrated 1000 Sols of exploration on Mars on May 31, 2015 – detailed here with our Sol 1000 mosaic also featured at Astronomy Picture of the Day on June 13, 2015.

As of today, Sol 1080, August 20, 2015, she has driven some 6.9 miles (11.1 kilometers) kilometers and taken over 260,000 amazing images.

Curiosity rover scans toward south east around Marias Pass area at the base of Mount Sharp on Mars on Sol 1074, Aug. 14, 2015 in this photo mosaic stitched from Mastcam color camera raw images. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer/kenkremer.com

Curiosity has already accomplished her primary objective of discovering a habitable zone on the Red Planet – at the Yellowknife Bay area – that contains the minerals necessary to support microbial life in the ancient past when Mars was far wetter and warmer billions of years ago.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

August 19, 2015December 23, 2015 by Ken Kremer

NASA Invites Public to ‘Send Your Name to Mars’ on InSight – Next Red Planet Lander

Sign up to send your name to Mars on InSight, NASA’s next mission to Mars launching in March 2016. Credit: NASA
Sign up link below – don’t delay![/caption]

Calling space fans worldwide: Now is your chance to participate in NASA’s human ‘Journey to Mars’ initiative and NASA’s next robotic mission to Mars – the InSight lander launching to the Red Planet next spring.

NASA invites you to ‘Send Your Name to Mars’ on a silicon microchip aboard the InSight probe slated for blastoff on March 4, 2016 from Vandenberg Air Force Base, California.

InSight’s science goal is totally unique – to “listen to the heart of Mars to find the beat of rocky planet formation.”

The public can submit their names for inclusion on a dime-sized microchip that will travel on a variety of spacecraft voyaging to destinations beyond low-Earth orbit, including Mars.

“Our next step in the journey to Mars is another fantastic mission to the surface,” said Jim Green, director of planetary science at NASA Headquarters in Washington.

“By participating in this opportunity to send your name aboard InSight to the Red Planet, you’re showing that you’re part of that journey and the future of space exploration.”

In just the first 24 hours over 67,000 Mars enthusiasts have already signed up!

But time is of the essence since the deadline to submit your name is soon: Sept. 8, 2015.

How can you sign up to fly on InSight? Is there a certificate?

NASA has made it easy to sign up.

To send your name to Mars aboard InSight, click on this weblink posted online by NASA:

http://go.usa.gov/3Aj3G

And you can also print out an elegant looking ‘Boarding Pass’ that looks like this:

Boarding Pass for NASA’s InSight Mission to Mars - launching from Vandenberg Air Force Base, California in March 2016. Credit: NASA — Boarding Pass with frequent flyer miles for NASA’s InSight Mission to Mars – launching from Vandenberg Air Force Base, California in March 2016. Credit: NASA

Furthermore the ‘Boarding Pass’ also comes with a listing of your “frequent flier” points accumulated by your participation in NASA’s ‘fly-your-name opportunity’ that will span multiple missions and multiple decades beyond low Earth orbit.

InSight represents the second ‘fly-your-name opportunity’ in NASA’s journey to Mars program. The uncrewed Orion EFT-1 mission launched on Dec. 5, 2014 was the first chance for space fans to collect ‘Journey to Mars’ points by sending your names to space.

The ‘Send Your Name to Mars’ campaign for Orion EFT-1 was a huge success.

Over 1.38 million people flew on the silicon chip aboard the maiden flight of Orion, the NASA capsule that will eventually transport humans to the Red Planet in the 2030s.

Don’t dawdle. Because after InSight, you’ll have to wait about three years until late 2018 and the blastoff of the next Orion capsule on NASA’s Exploration Mission-1 (EM-1) for you next chance to accumulate “frequent flier” points on a ‘Journey to Mars’ mission.

Orion EM-1 will launch atop NASA’s mammoth Space Launch System (SLS) rocket, and NASA just conducted a key test firing on Aug. 13 of the first stage engines that will power the stack to on a mission to the Moon – detailed in my recent story here.

InSight, which stands for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport, is a stationary lander.

It will join NASA’s surface science exploration fleet currently comprising of the Curiosity and Opportunity missions which by contrast are mobile rovers.

InSight is the first mission to understand the interior structure of the Red Planet. Its purpose is to elucidate the nature of the Martian core, measure heat flow and sense for “Marsquakes.”

“It will place the first seismometer directly on the surface of Mars to measure Martian quakes and use seismic waves to learn about the planet’s interior. It also will deploy a self-hammering heat probe that will burrow deeper into the ground than any previous device on the Red Planet. These and other InSight investigations will improve our understanding about the formation and evolution of all rocky planets, including Earth,” says NASA.

NASA's InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. As part of a series of deployment tests, the spacecraft was commanded to deploy its solar arrays in the clean room to test and verify the exact process that it will use on the surface of Mars. Credits: NASA/JPL-Caltech/Lockheed Martin — NASA’s InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. As part of a series of deployment tests, the spacecraft was commanded to deploy its solar arrays in the clean room to test and verify the exact process that it will use on the surface of Mars. Credits: NASA/JPL-Caltech/Lockheed Martin

The countdown clock is ticking relentlessly towards liftoff in less than seven months time in March 2016.

Insight promises to ‘science the sh**’ out of the heart of Mars!

It is funded by NASA’s Discovery Program as well as several European national space agency’s and countries. Germany and France are providing InSight’s two main science instruments; The HP3 heat probe and the SEIS seismometer through the Deutsches Zentrum für Luft- und Raumfahrt. or German Aerospace Center (DLR) and the Centre National d’Etudes Spatiales (CNES).

“Together, humans and robotics will pioneer Mars and the solar system,” says Green.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

August 19, 2015December 30, 2015 by Jason Major

Watch the You-Know-What Out Of This New Trailer for The Martian

The second full trailer for 20th Century Fox’s upcoming film The Martian dropped this morning and it looks like a whole red-planetful of awesome space adventure! Directed by Ridley Scott and based on the runaway hit novel of the same name by Andy Weir, The Martian stars Matt Damon as Mark Watney, a member of a fictional yet not-too-distant-future NASA mission to explore the surface of Mars. After a violent dust storm batters the camp the team is forced to abort the mission, abandoning the base and Watney, who was injured and assumed dead. Except, of course, he’s not, thus beginning his new mission to remain alive on Mars long enough to be rescued — a feat which will require bravery, brains, luck… and a whole you-know-what-load of science. (If you haven’t read the book yet, it’s a lot of fun. I highly suggest it.) So check out the trailer above, and feel free to repeat as necessary.

The Martian opens in U.S. theaters on Oct. 2. Visit the official movie site here.

August 17, 2015December 23, 2015 by Ken Kremer

Indian Mars Orbiter Shoots Spectacular New Images of Sheer Canyon and Curiosity’s Crater

This view over the Ophir Chasma canyon on the Martian surface was taken by the Mars Colour Camera aboard India’s Mars Orbiter Mission (MOM). Ophir Chasma is a canyon in the Coprates quadrangle located at 4° south latitude and 72.5° west longitude. It is part of the Valles Marineris canyon system. Credit: ISRO

India’s space agency has released a spectacular new batch of images taken by everyone’s favorite MOM – the Mars Orbiter Mission – the nation’s first probe ever dispatched to the Red Planet and which achieved orbit nearly a year ago.

The Indian Space Research Organization (ISRO) has published a beautiful gallery of images featuring a steep and stunning Martian canyon and the landing site of NASA’s Curiosity Mars Science Laboratory rover, and more.

The lead image was taken over the Ophir Chasma canyon on the Martian surface by the Mars Colour Camera aboard India’s Mars Orbiter Mission.

Ophir Chasma is a canyon in the Coprates quadrangle located at 4° south latitude and 72.5° west longitude. It is part of the Valles Marineris – the ‘Grand Canyon of Mars’ – and the largest known canyon in the Solar System.

The image was captured on July 19, 2015 from an altitude of 1857 kilometers (1154 miles). It has with a resolution of 96 meters.

The steep walled Ophir Chasma canyon contains many layers and the floors contain large deposits of layered materials, perhaps even sulfates.

Ophir Chasma is about 317 kilometers long and about 8 to 10 kilometers deep located near the center of Valles Marineris – see map below.

Valles Marineris stretches over 4,000 km (2,500 mi) across the Red Planet, is as much as 600 km wide and measures as much as 10 kilometers (6 mi) deep. It is nearly as wide as the United States.

Here’s an illuminating and magnificent 3D portrayal of Ophir Chasma created by Indian scientists that gives a sense of the canyons scale, sheer walls and cliffs and depth:

3D portrayals of Ophir Chasma terrain based on images taken by India’s Mars Orbiter Mission color camera on 19 July 2015 . Credit: ISRO

The newest images were snapped after the spacecraft exited the communications blackout encountered by all of Earth’s invasion fleet of Red Planet orbiters and rovers during the recent conjunction period when Mars was behind the sun during much of June.

See the prior image release from ISRO in my MOM story – here.

Here’s a wider view of Valles Marineris showing Ophir Chasma in a previously published MOM image from ISRO.

Valles Marineris from India’s Mars Mission. Credit: ISRO

ISRO also released a delightful new image of Gale Crater and the surrounding vicinity.

Gale Crater is the landing site of NASA’s Curiosity rover. MOM took the image from an altitude of 9004 kilometers.

Gale Crater - landing site of NASA’s Curiosity rover - and vicinity as seen by India’s Mars Orbiter Mission from an altitude of 9004 km. Gale crater is home to humongous Mount Sharp which rises 5.5 km from the crater floor and is easily visible in this photo. Credit: ISRO — Gale Crater – landing site of NASA’s Curiosity rover – and vicinity as seen by India’s Mars Orbiter Mission from an altitude of 9004 km. Gale crater is home to humongous Mount Sharp which rises 5.5 km from the crater floor and is easily visible in this photo. Credit: ISRO

Gale Crater is home to humongous Mount Sharp, a mountain that rises 5.5 kilometers (3.4 miles) from the crater floor and is easily visible in the photo from MOM. The crater is 154 kilometers (96 mi) wide.

Curiosity is currently exploring the foothills of Mount Sharp around the top of the image – which shows a rather different perspective from what we’ve seen from prior familiar orbital imagery snapped by several NASA and ESA orbiters.

The 1 ton rover recently celebrated the 3rd anniversary since its nailbiting touchdown inside Gale crater. And the new wider angle image from MOM gives a fabulous sense of exactly why a highly precise landing was essential – otherwise it would have been doomed.

Curiosity recently drilled into the “Buckskin” target at an outcrop at the foothills of Mount Sharp. See the mountain in our ground level mosaic from the crater floor. And its kind of neat to actually imagine Curiosity sitting there while perusing MOM’s photo.

MOM’s goal is to study Mars atmosphere, surface environments, morphology, and mineralogy with a 15 kg (33 lb) suite of five indigenously built science instruments. It is also sniffing for methane, a potential marker for biological activity.

MOM is India’s first deep space voyager to explore beyond the confines of her home planets influence and successfully arrived at the Red Planet after the “history creating” orbital insertion maneuver on Sept. 23/24, 2014 following a ten month journey from Earth.

The Indian probe arrived just after NASA’s MAVEN Mars orbiter, the first mission specifically targeted to study Mars tenuous upper atmosphere and the escape rates of atmospheric constituents.

MOM swoops around Mars in a highly elliptical orbit whose nearest point to the planet (periapsis) is at about 421 km and farthest point (apoapsis) at about 76,000 km, according to ISRO.

It takes MOM about 3.2 Earth days or 72 hours to orbit the Red Planet.

MOM was launched on Nov. 5, 2013 from India’s spaceport at the Satish Dhawan Space Centre, Sriharikota, atop the nations indigenous four stage Polar Satellite Launch Vehicle (PSLV) which placed the probe into its initial Earth parking orbit.

The $73 million MOM mission was expected to last at least six months. In March, ISRO extended the mission duration for another six months since its healthy, the five science instruments are operating fine and it has sufficient fuel reserves.

Including MOM, Earth’s invasion fleet at the Red Planet numbers a total of seven spacecraft comprising five orbiters from NASA, ESA and ISRO as well as the sister pair of mobile surface rovers from NASA – Curiosity and Opportunity.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Location of Ophir Chasma canyon inside this annotated map of Valles Marineris created from the THEMIS camera on NASA’s Mars Odyssey orbiter. Credit: NASA

Olympus Mons, Tharsis Bulge trio of volcanoes and Valles Marineris from ISRO's Mars Orbiter Mission. Note the clouds and south polar ice cap. Credit: ISRO — Olympus Mons, Tharsis Bulge trio of volcanoes and Valles Marineris from ISRO’s Mars Orbiter Mission. Note the clouds and south polar ice cap. Credit: ISRO

August 10, 2015December 23, 2015 by Ken Kremer

Yummy! ISS Astronauts Eat First Space-Grown Food

NASA Astronauts Kjell Lindgren (center) and Scott Kelly (right) and Kimiya Yui (left) of Japan consume space grown food for the first time ever, from the Veggie plant growth system on the International Space Station in August 2015. Credit: NASA TV

Video caption: That’s one small bite for a man, one giant leaf for mankind: NASA Astronauts Scott Kelly, Kjell Lindgren and Kimiya Yui of Japan sample the fruits of their labor after harvesting a crop of “Outredgeous” red romaine lettuce from the Veggie plant growth system on the International Space Station. Credit: NASA TV

Going where no astronauts have gone before, a trio of “space farmers” living aboard the International Space Station (ISS) have just become the first humans ever to eat food grown in space!

The gleeful munchers downed the freshly harvested crop of blood red colored “Outredgeous” red romaine lettuce salad during a live webcast today, Monday, August 10, direct from the Earth orbiting outpost soaring some 250 miles (400 km) above the home planet.

“Woo hoo ! …. Cheers!” exclaimed the eager Expedition 44 astronauts comprising Kjell Lindgren, Scott Kelly and Kimiya Yui, at the moment of truth, as they consumed the fruits of their own labor.

“It was one small bite for man, one giant leap for #NASAVEGGIE and our #JourneytoMars. #YearInSpace,” tweeted Kelly.

The momentous salad eating event took place at 12:26 EDT from beside the innovative and groundbreaking “Veggie” plant growth system, housed inside the European Space Agency’s Columbus laboratory located at the end of the US section of the ISS.

“That’s awesome!” said Lindgren with a broad smile – to the audible crunchy sounds of chewing on the freshly cut space lettuce.

“Tastes good!” replied Kelly, upon happily consuming the red leafed vegetable. He is now in the 5th month of his planned 1 Year mission aboard the ISS.

“Chomp! Our first veggies were harvested & consumed by astronauts in space!” tweeted NASA.

They all welcomed the opportunity to sample some freshly grown space produce from their miniature “ space farm.” Resident ISS crewmembers have been waiting for the “GO” to eat for some time.

“It tastes like arugula,” added Kelly, as they first tried the lettuce plain, as a control taste test of the virgin crop to get “the full effect.”

“It’s fresh,” Lindgren responded.

Then they doused quickly it with some oil and vinegar for flavor comparison.

“After trying the lettuce plain, @astro_kjell and @StationCDRKelly added oil & vinegar!” NASA tweeted.

Lindgren had carefully and methodically snipped away about half of the lettuce crop, on live NASA TV – which had grown to quite a size under the carefully maintained conditions inside “Veggie.”

He then cleaned “the leafy greens” by placing them between citric acid-based, food safe sanitizing wipes before the taste test.

After momentarily bagging the harvest, he distributed samples to his “tastemates” and the fun began.

“It’s wonderful to eat fresh food on the ISS, which is a lot of white and aluminum and it’s kind of a sterile environment,” said Kelly.

So this was quite different.

“It’s really fun to see green, growing things in here that we’re intentionally growing for sustenance. So we sure appreciate this payload and the opportunity to grow and eat and harvest these crops.”

The joyful trio saved some for the produce for their three Russian station colleagues to try later – Oleg Kononenko, Gennady Padalka and Mikhail Kornienko. Two of the Russian cosmonauts, Expedition 44 commander Padalka and Kelly’s 1 year crew mate Kornienko, were conducting a spacewalk today, simultaneously to the lettuce taste testing.

This "Outredgeous" red romaine lettuce was grown inside the Veggie plant growth system on the ISS and eaten on August 10, 2015 by the station crew. The goal was to test hardware for growing vegetables and other plants to be harvested and eaten by astronauts in space. Credits: NASA TV — This “Outredgeous” red romaine lettuce was grown inside the Veggie plant growth system on the ISS and eaten on August 10, 2015 by the station crew. The goal was to test hardware for growing vegetables and other plants to be harvested and eaten by astronauts in space. Credits: NASA TV

Another portion was set aside “to be packaged and frozen on the station until it can be returned to Earth for scientific analysis,” said NASA.

Although some vegetables have been grown before on the station, including prior crops of lettuce from “Veggie,” today marked the first time that any astronauts were “officially” granted “permission” to eat the fruits of their labor. Russian cosmonauts have eaten their station crops in the past. It’s a mystery whether any partner crewmates surreptitiously tasted some of the Russian produce.

And it not just for fun. In fact growing edible space food marks a significant new milestone towards enabling deep space human exploration, as explained by Kelly.

“Having lived on the space station for a while, I understand the logistical complexity of having people work in space for long periods and the supply chain that’s required to keep us going,” Kelly remarked.

“If we’re ever going to go to Mars someday, and we will, we’re going to have a spacecraft that is much more self sustainable with regard to its food supply.”

Experiments like these are critical for NASA’s plans to send humans on a “Journey to Mars” in the 2030s.

The “Journey to Mars” and back is likely to take well over two years and resupply is not possible. Crews will have to grow at least a portion of their own food and today’s experiment helps pave the human path to the Red Planet.

The “Veggie” experiment was developed by Orbital Technologies Corp. (ORBITEC) in Madison, Wisconsin.

The Veggie-01 apparatus was thoroughly tested at Kennedy before flight. It was delivered, along with two sets of pillows containing the romaine seeds and one set of zinnias, to the ISS by the SpaceX-3 Dragon cargo resupply mission launched in April 2014.

NASA astronaut Kjell Lindgren displays the “Outredgeous" red romaine lettuce grown inside the Veggie plant growth system on the ISS prior to harvesting and consumption on August 10, 2015. Credit: NASA TV — NASA astronaut Kjell Lindgren displays the “Outredgeous” red romaine lettuce grown inside the Veggie plant growth system on the ISS prior to harvesting and consumption on August 10, 2015. Credit: NASA TV

The lettuce crop inside the Veggie-01 plant pillows were activated by Kelly on July 8. They were grown for 33 days before being harvested today. The seeds had been stored dormant on the station for some 15 months since arriving aboard the SpaceX-3 Dragon, according to NASA.

The collapsible and expandable Veggie unit features a flat panel light bank that includes red, blue and green LEDs for plant growth and crew observation.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Veggie demonstration apparatus growing red romaine lettuce under LED lights in the Space Station Processing Facility at NASA’s Kennedy Space Center. Credit: Ken Kremer/kenkremer.com

August 4, 2015December 23, 2015 by Ken Kremer

Curiosity Drills Deep into First High Silica Martian Rock on Third Touchdown Anniversary

Curiosity extends robotic arm and conducts sample drilling at “Buckskin” rock target at bright toned “Lion” outcrop at the base of Mount Sharp on Mars, seen at right, during August 2015. Gale Crater eroded rim seen in the distant background at left, in this composite multisol mosaic of navcam raw images taken to Sol 1059, July 30, 2015. Navcam camera raw images stitched and colorized. Inset: MAHLI color camera up close image of full depth drill hole at “Buckskin” rock target on Sol 1060. Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/kenkremer.com/Marco Di Lorenzo
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NASA’s Curiosity Mars Science Laboratory (MSL) rover has successfully drilled into the first high silica rock target on Mars after recently discovering this new type of rock that’s unlike any found before – as she is about to mark the 3rd anniversary since the hair-raising touchdown on the Red Planet.

The SUV-sized rover bored a full depth hole into a Mars outcrop at a target dubbed “Buckskin” as commanded by the mission team over the weekend, after first conducting a mini drill test to assess the safety of the intended drill campaign to sample the alien rock interior beneath the Martian crater floor.

“This morning, the MSL operations team was very happy to see that drilling into Buckskin was successful!” said Ken Herkenhoff, Research Geologist at the USGS Astrogeology Science Center and an MSL science team member, in a mission update.

Confirmation of the success of the full depth drilling into “Buckskin” on Sol 1060 at the bright toned “Lion” outcrop came later after receipt of new high resolution images from the rover showing the approximately 1.6 cm (0.63 inch) diameter bore hole next to the initial mini hole test, along with the indicative residue of grey colored tailings from the Martian subsurface seen distributed around the new hole.

“Successful drilling at Buckskin!” added team member Professor John Bridges of the University of Leicester, England, in an update.

“Like the other drill holes this is showing how thin red Mars is,” Bridges elaborated.

Beneath a thin veneer of rusty red colored iron oxide, the Red Planet is remarkably grey as demonstrated by Curiosity’s prior drilling campaigns.

The hole was bored to a full depth of about 2.6 inches (6.5 centimeters) using the percussion drill on the terminus of the 7 foot-long (2.1 meter-long) robotic arm.

Buckskin was “chosen because this sedimentary horizon has some very high silica enrichments,” Bridges explains.

The findings of elevated levels of silicon as well as hydrogen were derived from data collected by Curiosity’s laser-firing Chemistry & Camera (ChemCam) and Dynamic Albedo of Neutrons (DAN) instruments on certain local area rocks.

Silica is a rock-forming compound containing silicon and oxygen, commonly found on Earth as quartz.

“High levels of silica could indicate ideal conditions for preserving ancient organic material, if present, so the science team wants to take a closer look,” say mission team officials.

See the rover at work reaching out with her robotic arm and drilling into Buckskin, as illustrated in our new mosaics of mastcam and navcam camera raw images created by the image processing team of Ken Kremer and Marco Di Lorenzo (above and below).

“Buckskin” sits at the base of Mount Sharp, a huge layered mountain that dominates the center of the 96 mile-wide (154 kilometers-wide) Gale Crater landing site.

Exploring the sedimentary layers of Mount Sharp, which towers 3.4 miles (5.5 kilometers) into the Martian sky, is the primary destination and goal of the rovers long term scientific expedition on the Red Planet.

The silica enrichment “may have occurred as the Gale sediments were altered by subsurface fluids after burial. As the basaltic composition was altered (as we saw from the clay and Fe oxide at Yellowknife Bay) ultimately a lot of silica is released which can be precipitated at horizons like this,” explains Bridges.

The Curiosity Mars Science Laboratory (MSL) rover safely touched down on the crater floor on August 5, 2012 following the unprecedented and nail-biting sky crane maneuver that delivered her with pinpoint precision to a landing site nearby Mount Sharp inside Gale Crater.

The goal of the drilling is to provide geologic context for Curiosity’s long term climb up the mountains sedimentary layers by collecting samples to assess the habitability of the Red Planet over billions of years of time.

So the plan was for the robot to process and pulverize the samples for eventual delivery to the onboard pair of miniaturized chemistry labs located inside her belly – SAM and CheMin. Tiny samples are fed to a trio of inlet ports on the rover deck through the sieved filters.

Images are taken to document and assess the entire sample collection and delivery process.

After gathering the Buckskin sample, a portion was transferred to the robots scoop for inspection.

Then the first portion was successfully fed into CheMin for inorganic elemental analysis over the weekend.

“The activities planned for last weekend completed successfully, including sample dropoff to CheMin and analysis of the minerals present,” Herkenhoff confirmed.

The one ton robots next steps involve “dumping the portion of the drill sample that has not been sieved and Mastcam, ChemCam, MAHLI, and APXS observations of the dump pile. ChemCam and Mastcam will also observe nearby targets “Martz” and “Mountain Home.” MAHLI will image the drill hole, tailings and CheMin inlet at night using its LEDs for illumination.”

Curiosity MAHLI camera image taken of Buckskin drill hole on Sol 1060 on July 31, 2015. Credit: NASA/JPL/MSSS

After completing these science activities, the six wheeled rover will move on to the next exciting destination.

“It’s been a great couple of weeks at the Lion outcrop, but it’s time to move on,” says Lauren Edgar, Research Geologist at the USGS Astrogeology Science Center and an MSL science team member, in the latest mission update from today, August 4, Sol 1065.

“After a successful investigation that included observations by almost every science instrument, we’re getting ready to drive away tomorrow. That means that today (and tomorrow before we drive) is the last call for science observations.”

For about the past two months, the six wheeled robot has been driving around and exploring a geological contact zone named “Marias Pass” – an area on lower Mount Sharp, by examining the rocks and outcrops with her suite of state-of-the-art science instruments.

“Marias Pass” is a geological context zone where two rock types overlap – pale mudstone meets darker sandstone.

The prior hole was drilled at Telegraph Peak on Feb. 24, 2015, on Sol 908.

Curiosity recently celebrated 1000 Sols of exploration on Mars on May 31, 2015 – detailed here with our Sol 1000 mosaic also featured at Astronomy Picture of the Day on June 13, 2015.

NASA’s Martian Curiosity rover looks backs to 1000 Sols of science and exploration on the surface of the Red Planet. Robot wheel tracks lead back through valley dunes. Gale Crater rim seen in the distant hazy background. Sol 997 (May 28, 2015) navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/ Marco Di Lorenzo/Ken Kremer/kenkremer.com Featured on APOD on June 13, 2015 — NASA’s Martian Curiosity rover looks backs to 1000 Sols of science and exploration on the surface of the Red Planet. Robot wheel tracks lead back through valley dunes. Gale Crater rim seen in the distant hazy background. Sol 997 (May 28, 2015) navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/ Marco Di Lorenzo/Ken Kremer/kenkremer.com
Featured on APOD on June 13, 2015

As of today, Sol 1065, August 4, 2015, she has driven some 11 kilometers and taken over 256,000 amazing images.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Curiosity extends robotic arm and conducts test drill at “Buckskin” rock target at bright toned “Lion” outcrop on the lower region of Mount Sharp on Mars, seen at right. Gale Crater eroded rim seen in the distant background at left, in this composite multisol mosaic of navcam raw images taken to Sol 1059, July 30, 2015. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer/kenkremer.com/Marco Di Lorenzo

July 31, 2015December 23, 2015 by Ken Kremer

Curiosity Discovers Mars Rock Like None Before, Sets Drill Campaign

On the eve of the 3rd anniversary since her nail biting touchdown inside Gale Crater, NASA’s car sized Curiosity Mars Science Laboratory (MSL) rover has discovered a new type of Martian rock that’s surprisingly rich in silica – and unlike any other targets found before.

Excited by this new science finding on Mars, Curiosity’s handlers are now gearing the robot up for her next full drill campaign today, July 31 (Sol 1060) into a rock target called “Buckskin” – which lies at the base of Mount Sharp, the huge layered mountain that is the primary science target of this Mars rover mission.

“The team selected the “Buckskin” target to drill,” says Lauren Edgar, Research Geologist at the USGS Astrogeology Science Center and an MSL science team member, in a mission update.

“It’s another exciting day on Mars!”

See the rover at work reaching out with her robotic arm and drilling into Buckskin, as illustrated in our new mosaics of navcam camera images created by the image processing team of Ken Kremer and Marco Di Lorenzo (above and below). Also featured at Alive Universe Images – here.

NASA Curiosity rover inspects ‘Buckskin’ rock outcrop on Mars with APXS mineral spectrometer in this hazcam camera raw image taken on July 29, 2015 (Sol 1058), colorized and linearized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer/kenkremer.com

The goal is to provide geologic context for her long term expedition up the mountains sedimentary layers to study the habitability of the Red Planet over eons of time.

Data from Curiosity’s “laser-firing Chemistry & Camera (ChemCam) and Dynamic Albedo of Neutrons (DAN), show elevated amounts of silicon and hydrogen, respectively,” in certain local area rocks, according to the team.

Silica is a rock-forming compound containing silicon and oxygen, commonly found on Earth as quartz.

“High levels of silica could indicate ideal conditions for preserving ancient organic material, if present, so the science team wants to take a closer look.”

Curiosity conducts test drill at “Buckskin” rock target at bright toned “Lion” outcrop on the lower region of Mount Sharp on Mars. Gale crater rim seen in the distant background, in this composite mosaic of navcam raw images taken to Sol 1059, July 30, 2015. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer/kenkremer.com/Marco Di Lorenzo Inset: MAHLI camera up close image of test drill at “Buckskin” rock target. Credit: NASA/JPL-Caltech/MSSS — Curiosity extends robotic arm and conducts test drill at “Buckskin” rock target at bright toned “Lion” outcrop on the lower region of Mount Sharp on Mars. Gale crater rim seen in the distant background, in this composite mosaic of navcam raw images taken to Sol 1059, July 30, 2015. Inset: MAHLI camera up close image of test drill at “Buckskin” rock target. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer/kenkremer.com/Marco Di Lorenzo Credit: NASA/JPL-Caltech/MSSS

Therefore the team scouted targets suitable for in depth analysis and sample drilling and chose “Buckskin”.

“Buckskin” is located among some high-silica and hydrogen enriched targets at a bright outcrop named “Lion.”

An initial test bore operation was conducted first to confirm whether that it was indeed safe to drill into “Buckskin” and cause no harm to the rover before committing to the entire operation.

The bore hole is about 1.6 cm (0.63 inch) in diameter.

“This test will drill a small hole in the rock to help determine whether it is safe to go ahead with the full hole,” elaborated Ryan Anderson, planetary scientist at the USGS Astrogeology Science Center and an MSL science team member.

So it was only after the team received back new high resolution imagery last night from the arm-mounted MAHLI camera which confirmed the success of the mini-drill operation, that the “GO” was given for a full depth drill campaign. MAHLI is short for Mars Hand Lens Imager.

“We successfully completed a mini drilling test yesterday (shown in the MAHLI image). That means that today we’re going for the FULL drill hole” Edgar confirmed.

“GO for Drilling.”

So it’s a busy day ahead on the Red Planet, including lots of imaging along the way to document and confirm that the drilling operation proceeds safely and as planned.

“First we’ll acquire MAHLI images of the intended drill site, then we’ll drill, and then we’ll acquire more MAHLI images after drilling,” Edgar explains.

“The plan also includes Navcam imaging of the workspace, and Mastcam imaging of the target and drill bit. In addition to drilling, we’re getting CheMin ready to receive sample in an upcoming plan. Fingers crossed!” Surface observations with the arm-mounted Alpha Particle X-ray Spectrometer (APXS) instrument are also planned.

If all goes well, the robot will process and pulverize the samples for eventual delivery to the onboard pair of miniaturized chemistry labs located inside her belly – SAM and CheMin. Tiny samples will be fed to the inlet ports on the rover deck through the sieved filters.

A rock outcrop dubbed "Missoula," near Marias Pass on Mars, is seen in this image mosaic taken by the Mars Hand Lens Imager on NASA's Curiosity rover. Pale mudstone (bottom of outcrop) meets coarser sandstone (top) in this geological contact zone, which has piqued the interest of Mars scientists. Credit: NASA/JPL-Caltech/MSSS — A rock outcrop dubbed “Missoula,” near Marias Pass on Mars, is seen in this image mosaic taken by the Mars Hand Lens Imager on NASA’s Curiosity rover. Pale mudstone (bottom of outcrop) meets coarser sandstone (top) in this geological contact zone, which has piqued the interest of Mars scientists. Credit: NASA/JPL-Caltech/MSSS

Meanwhile the team is studying a nearby rock outcrop called “Ch-paa-qn” which means “shining peak” in the native Salish language of northern Montana.”

Anderson says the target is a bright patch on a nearby outcrop. Via active and passive observations with the mast-mounted ChemCam laser and Mastcam multispectral imager, the purpose is to determine if “Ch-paa-qn” is comprised of calcium sulfate like other white veins visible nearby, or perhaps it’s something else entirely.

A rock fragment dubbed "Lamoose" is shown in this picture taken by the Mars Hand Lens Imager (MAHLI) on NASA's Curiosity rover. Like other nearby rocks in a portion of the "Marias Pass" area of Mt. Sharp, Mars, it has unusually high concentrations of silica. The high silica was first detected in the area by the Chemistry & Camera (ChemCam) laser spectrometer. This rock was targeted for follow-up study by the MAHLI and the arm-mounted Alpha Particle X-ray Spectrometer (APXS). Credits: NASA/JPL-Caltech/MSSS — A rock fragment dubbed “Lamoose” is shown in this picture taken by the Mars Hand Lens Imager (MAHLI) on NASA’s Curiosity rover. Like other nearby rocks in a portion of the “Marias Pass” area of Mt. Sharp, Mars, it has unusually high concentrations of silica. The high silica was first detected in the area by the Chemistry & Camera (ChemCam) laser spectrometer. This rock was targeted for follow-up study by the MAHLI and the arm-mounted Alpha Particle X-ray Spectrometer (APXS). Credits: NASA/JPL-Caltech/MSSS

Before arriving by the “Lion” outcrop last week, Curiosity was investigating another outcrop area nearby, the high-silica target dubbed “Elk” with the ChemCam instrument, while scouting around the “Marias Pass” area in search of tasty science targets for in-depth analysis.

Sometimes the data subsequently returned and analyzed is so extraordinary, that the team decides on a return trip to a spot previously departed. Such was the case with “Elk” and the rover was commanded to do a U-turn to acquire more precious data.

“One never knows what to expect on Mars, but the Elk target was interesting enough to go back and investigate,” said Roger Wiens, the principal investigator of the ChemCam instrument from the Los Alamos National Laboratory in New Mexico.

Soon, ChemCam will have fired on its 1,000th target. Overall the laser blaster has been fired more than 260,000 times since Curiosity landed inside the nearly 100 mile wide Gale Crater on Mars on Aug. 6, 2012, alongside Mount Sharp.

“ChemCam acts like eyes and ears of the rover for nearby objects,” said Wiens.

“Marias Pass” is a geological context zone where two rock types overlap – pale mudstone meets darker sandstone.

The rover spotted a very curious outcrop named “Missoula.”

“We found an outcrop named Missoula where the two rock types came together, but it was quite small and close to the ground. We used the robotic arm to capture a dog’s-eye view with the MAHLI camera, getting our nose right in there,” said Ashwin Vasavada, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

White mineral veins, possibly comprised of calcium sulfate, filled the fractures by depositing the mineral from running groundwater.

“Such clues help scientists understand the possible timing of geological events,” says the team.

Read more about Curiosity in an Italian language version of this story at Alive Universe Images – here.

As of today, Sol 1060, July 31, 2015, she has taken over 255,000 amazing images.

Curiosity recently celebrated 1000 Sols of exploration on Mars on May 31, 2015 – detailed here with our Sol 1000 mosaic also featured at Astronomy Picture of the Day on June 13, 2015.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer