Posted on by Steve Nerlich

Eyes On The Solar System

Eyes on the Solar System - a 3d environment browser application that operates in real time, letting you see what our robot spacecraft are up to.

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NASA’s beta version of Eyes on the Solar System, built by JPL and Caltech, offers a neat way of tracking a range of current space missions – for example, as Nancy Atkinson mentioned yesterday, you can follow EPOXI’s flyby of comet Hartley 2. Reminiscent of Celestia, this browser application gives you a 3D environment running in real time and is updated regularly with NASA spacecraft mission data.

To get it operating, you can just click to the NASA link where you are prompted to install a Unity Web Player plug-in. This is fast and straight forward, from my experience. I did strike a problem with a certain small and squishy 64bit system that starts with X (where the menu text didn’t display correctly), but it ran fine on other systems. It is a beta version after all – and I feel obliged to note you should load at your own risk, yada, yada.

Anyhow, if you choose to proceed, you can then move around the solar system with left mouse click-hold and scroll wheel actions – or there’s the usual keyboard alternatives, or even on-screen controls. In default mode, a number of celestial bodies are shown and labeled, as are several spacecraft, which you can zoom over to by clicking on them. You can add more objects from the Visual Controls menu. Default settings have comets hidden, so you’ll need to add them to do an EPOXI-Hartley 2 encounter simulation.

There are some online tutorials you can take from the opening screen – which are short and useful – to get a quick run-through of the options available.

Eyes - in photo mode - showing EPOXI on approach to Hartley 2. If you're not a purist, you can also back-light an image. For example, to light up EPOXI in this image - where the Sun is not at the right angle to do it.

Like Celestia, you can speed up, slow down and move back and forth through time. This means you can replay EPOXI’s closest approach to Hartley 2 – or go right back to 1997 and zoom out to watch Cassini leave Earth and travel to Saturn via Venus and Earth flybys until it reaches Saturn in 2004 – all of which you can enjoy in about 5 seconds after cranking up the passage of time. You can also pick an ‘over the shoulder’ view to ride with Cassini through the F and G rings on its first approach to Saturn.

Unlike Celestia, because Eyes is mainly about spacecraft missions, its environment only covers the period from 1950 to 2050 and (curses) I couldn’t find any options to add in fictional spacecraft.

For a bit of edu-tainment you can access right-click controls which allow you to measure distances between objects – and monitor how those distances change as the objects move over time. For a bit of fun, you can also compare spacecraft to scale objects – with a choice between scientist, Porsche and football stadium. As one of the brief tutorials will explain, Voyager 1 is about the size of a Porsche.

Posted on by Nancy Atkinson

Mysterious Ribbon at Edge of Solar System is Changing

A year ago, researchers from the IBEX mission – NASA’s Interstellar Boundary Explorer – announced the discovery of an unexpected bright band or ribbon of surprisingly high energy emissions at the boundary between our solar system and interstellar space. Now, after a year of observations, scientists have seen vast changes, including an unusual knot in the ribbon which appears to have ‘untied.’ Changes in the ribbon — a ‘disturbance in the force,’ so to speak, along with a shrunken heliosphere, may be allowing galactic cosmic rays to leak into our solar system.
Continue reading “Mysterious Ribbon at Edge of Solar System is Changing”

Posted on by Nancy Atkinson

An Alien’s View of Our Solar System

We have just begun to try and image distant solar systems around other stars, and hopefully our techniques and technology will improve in the near future so that we can one day find — and take pictures of — planets as small as Earth. But what if another civilization from a distant star was looking at us? What would they see? A new supercomputer simulation tracking the interactions of thousands of dust grains show what our solar system might look like to alien astronomers searching for planets. It also provides a look back to how our planetary system may have changed and matured over time.

Continue reading “An Alien’s View of Our Solar System”

Posted on by Nancy Atkinson

Astronomers Find 14 New Trans-Neptunian Objects Hiding in Hubble Data

This is an artist's concept of a craggy piece of Solar System debris that belongs to a class of bodies called trans-Neptunian objects (TNOs).Credit: NASA, ESA, and G. Bacon (STScI)

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Out beyond the orbit of Neptune lurk millions of icy bodies called Trans-Neptunian Objects. We haven’t found and seen them them all yet, but astronomers have theorized the numbers. However, since 1992, nearly a thousand TNOs have been observed. Most of them are very small and receive little sunlight, which makes them faint and difficult to spot. But a group of astronomers have devised a clever new technique to find TNOs and discovered 14 just by using archived data from the Hubble Space Telescope, and they hope to be able to uncover hundreds more.

“Trans-Neptunian objects interest us because they are building blocks left over from the formation of the solar system,” said lead author Cesar Fuentes.

As TNOs slowly orbit the sun, they move against the starry background, appearing as streaks of light in time exposure photographs. The team developed software to analyze hundreds of Hubble images hunting for such streaks. After promising candidates were flagged, the images were visually examined to confirm or refute each discovery.

Most TNOs are located near the ecliptic — a line in the sky marking the plane of the solar system (since the solar system formed from a disk of material). Therefore, the team searched within 5 degrees of the ecliptic to increase their chance of success.

The 14 objects include one binary system, kind of like a mini Pluto-Charon system. All were very faint, with most measuring magnitude 25-27 (more than 100 million times fainter than objects visible to the unaided eye).

Additionally, by measuring their motion across the sky, astronomers were able to calculate the orbit and distance for each object. Combining the distance and brightness (plus an assumed albedo or reflectivity), they then estimated the size. The newfound TNOs range from 25 to 60 miles (40-100 km) across.

Unlike planets, which tend to have very flat orbits (known as low inclination), some TNOs have orbits significantly tilted from the ecliptic (high inclination). The team examined the size distribution of TNOs with low- versus high-inclination orbits to gain clues about how the population has evolved over the past 4.5 billion years.

Generally, smaller trans-Neptunian objects are the shattered remains of bigger TNOs. Over billions of years, these objects smack together, grinding each other down. The team found that the size distribution of TNOs with low- versus high-inclination orbits is about the same as objects get fainter and smaller. Therefore, both populations (low and high inclination) have similar collisional histories.

This initial study examined only one-third of a square degree of the sky, meaning that there is much more area to survey. Hundreds of additional TNOs may be hiding in the Hubble archives at higher ecliptic latitudes. Fuentes and his colleagues intend to continue their search.

“We have proven our ability to detect and characterize TNOs even with data intended for completely different purposes,” Fuentes said.

This research has been accepted for publication in The Astrophysical Journal.

Read the team’s abstract.

Source: CfA

Posted on by Nancy Atkinson

Win ‘Star Walk’ and ‘Solar Walk’ Astronomy Apps

I’ve had a couple of people excitedly show me the Star Walk astronomy app on their iPhones and ipads, and it really is great. You can hold your device up to the sky and it will show you a sky map of your exact position. Move your device around the sky, and it moves with you. It is a very high quality, dynamic and realistic stargazing guide, which — if you are a beginning or experienced astronomer — makes skywatching easy for everybody! There is also a “Solar Walk” app — which has very cool 3D images, so grab your 3D glasses to fully enjoy. See more about this app below.
Continue reading “Win ‘Star Walk’ and ‘Solar Walk’ Astronomy Apps”

Posted on by Nancy Atkinson

Contest: Win “Wonders of the Solar System” DVD


If you didn’t have the chance to see Brian Cox’s series “Wonders of the Solar System” which aired on the BBC earlier this year and the Science Channel in August, we’ve got some good news for you: it comes out on DVD and Blu-ray in the US on September 7. But there’s even better news for readers of Universe Today: We have five – count ‘em – five copies to give away, courtesy of the BBC and Bender Helper Impact marketing agency. “Wonders” is an extraordinary look at our world and solar system, and is rich with breathtaking images beamed back from the fleet of probes, rovers and telescopes currently in space, and is a “must-see” for any space and astronomy enthusiast.

To enter the contest, send an email to [email protected] with “Wonders DVD” in the subject line. Deadline for entry is Wednesday, September 8 at 12 pm PDT. Winners will have their choice of “Wonders” on DVD or Blu-ray.

See more info below about this remarkable series, including a video trailer that will give a taste of this great series.

Wonders of the Solar System” is a 3-disc set, and the series is presented by renowned physicist Brian Cox who will explore some of the most amazing features of our planet’s own backyard. Witness how forces of nature carved out beauty and order from the chaos of space and learn how our home planet is not isolated, but intimately connected with the rest of the solar system. Using the latest scientific knowledge, state of the art CGI, along with stunning images paired up with some of the most spectacular, extreme locations on Earth to help reveal wonders never thought possible. Included are two bonus programs, “What on Earth Is Wrong with Gravity?” and “Do You Know What Time It Is?”

See more about “Wonders” or you can put in an order to purchase on Amazon.

Posted on by Nancy Atkinson

Contest: Win “The Universe: Our Solar System” in Blu-ray


A new giveaway opportunity! This time it is the Blu-ray edition of The Universe: Our Solar System.

The Blu-ray edition of the History Channel’s The Universe consists of 10 episodes from the first season, and uses cutting-edge computer-generated imagery to bring distant planets and faraway stars up close. We’ve long been fascinated with the sky and outerspace, and in this series, history and science collide to investigate all we know about the Universe.

To win, send an email to [email protected] with “Solar System” in the subject line. Fraser will randomly pick one email as the winner. Deadline is Monday, August 30 at 12 pm PDT.

Find out about The Universe: Our Solar System at this link.

And by the way, the winner of the new book about the Sloan Digital Sky Survey, “The Grand and Bold Thing” by Ann Finkbeiner, was Irfaan Hamdulay from Cape Town, South Africa. Congrats!

This is a two-disc set:

DISC 1: Secrets of the Sun / Mars: The Red Planet / The End of the Earth: Deep Space Threats To Our Planet / Jupiter: The Giant Planet / The Moon

DISC 2: Spaceship Earth / The Inner Planets: Mercury & Venus / Saturn: Lord of the Rings / Alien Galaxies / Life and Death of a Star

In this series you can witness the sun’s birth at the dawn of our solar system, and its death, billions of years in the future; explore the possibility of a human settlement on Mars; and learn about the devastating threats posed by the meteorites, comets, and asteroids that routinely collide with Earth.

Each of the 44-minute episodes begins with a general introduction of subjects ranging from the sun to individual planets. Each topic is then broken down into a series of segments that detail specific ideas, theories, or components integral to the understanding of the main topic as well as historical material, current studies and theories, and projections of potential future events and scientific advances.

Posted on by Nancy Atkinson

Our Solar System: Now 2 Million Years Older

Why Do Planets Orbit the Sun
The Solar System

Our solar system is beautiful and aging gracefully, but it might be even older than we originally thought, by as much as 2 million years. A group of scientists analyzed lead isotopes within a 1.49-kilo (3.2-pound) meteorite found in the Moroccan desert in 2004 and found evidence that suggests the mineral was formed 4.56 billion years ago, making the meteorite the oldest object ever found. This finding is between 300,000 and 1.9 million years older than previous estimates.

Marking the age of the Solar System has been defined as the time of formation of the first solid grains in the nebular disc surrounding the proto-Sun, and this has been done previously dating calcium–aluminium-rich inclusions in meteorites.

The team, led by Audrey Bouvier and Meenakshi Wadhwa of Arizona State University’s the Center for Meteorite Studies, looked at the extent to which uranium-238 and uranium-235 isotopes had decayed into their daughter isotopes lead-207 and lead-206.

Previous studies that dated the solar system looked at the Efremovka and Allende meteorites found in Kazakhstan in 1962 and Mexico in 1969, respectively.

While the timing may not seem like a big difference for something that is billions of years old, Bouvier said in New Scientist that it could make a difference when pinning down the conditions that led to the solar system’s formation, and those needed for other life-friendly planetary systems to form.

Their study was published by the journal Nature Geoscience.

Nature paper: Bouvier, A. & Wadhwa, M. Nature Geosci. advance online publication doi:10.1038/NGEO941 (2010).

Sources: New Scientist, PhysOrg

Posted on by Nancy Atkinson

The Earth and Moon May Have Formed Later Than Previously Thought

The collision between "Proto-Earth" and Theia, from which the Earth and Moon were created 4,500-4,400 million years ago. Both planets had a massive iron core when they collided and created the Moon and Earth.

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The Earth and Moon were created as the result of a giant collision between two planets the size of Mars and Venus. Until now it was thought to have happened when the solar system was 30 million years old or approximately 4.5 billion years ago. But new research shows that the Earth and Moon may have formed much later – perhaps up to 150 million years after the formation of the solar system.

“We have determined the ages of the Earth and the Moon using tungsten isotopes, which can reveal whether the iron cores and their stone surfaces have been mixed together during the collision,” said Tais W. Dahl, from the Niels Bohr Institute at the University of Copenhagen in collaboration with professor David J. Stevenson from the California Institute of Technology (Caltech).

The planets in the solar system were created by collisions between planetary embryos orbiting the newborn sun. In the collisions the small planets congealed together and formed larger and larger planets. When the gigantic collision occurred that ultimately formed the Earth and Moon, it happened at a time when both planetary bodies had a core of metal (iron) and a surrounding mantle of silicates (rock). But when did it happen and how did it happen? The collision took place in less than 24 hours and the temperature of the Earth was so high (7000º C), that both rock and metal must have melted in the turbulent collision. But were the stone mass and iron mass also mixed together?

The age of the Earth and Moon can be dated by examining the presence of certain elements in the Earth’s mantle. Hafnium-182 is a radioactive substance, which decays and is converted into the isotope tungsten-182. The two elements have markedly different chemical properties and while the tungsten isotopes prefer to bond with metal, hafnium prefers to bond to silicates, i.e. rock.

It takes 50-60 million years for all hafnium to decay and be converted into tungsten, and during the Moon forming collision nearly all the metal sank into the Earth’s core. But did all the tungsten go into the core?

“We have studied to what degree metal and rock mix together during the planet forming collisions. Using dynamic model calculations of the turbulent mixing of the liquid rock and iron masses we have found that tungsten isotopes from the Earth’s early formation remain in the rocky mantle,” said Tahl.

The new studies imply that the moon forming collision occurred after all of the hafnium had decayed completely into tungsten.

“Our results show that metal core and rock are unable to emulsify in these collisions between planets that are greater than 10 kilometers in diameter and therefore that most of the Earth’s iron core (80-99 %) did not remove tungsten from the rocky material in the mantle during formation” said Dahl.

The result of the research means that collision that created the Earth and the Moon may have occurred as much as 150 million years after the formation of the solar system, much later than the 30 million years that was previously thought.

The research results have been published in the scientific journal, Earth and Planetary Science Letters.

From a University of Copenhagen press release.

Posted on by Nancy Atkinson

Voyager 2 Update from Dr. Ed Stone

Artist impression of Voyager. Image credit: NASA/JPL

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In early May 2010, the 33-year-old Voyager 2 spacecraft experienced an anomaly where the data it returned to Earth was unreadable. Engineers diagnosed the problem as a flip of a bit in the memory in the flight data system computer that packages data to transmit back to Earth, and were able to successfully reset the computer. On May 23, Voyager 2 sent back data that was again formatted properly, but the teams wanted to check out all the systems on the spacecraft to make sure everything was working properly. We checked in with Dr. Ed Stone, former director of JPL and the project scientist for the Voyager project since 1972 to get the latest news on how Voyager 2’s checkout is progressing.

“The science teams have confirmed that Voyager 2 is again transmitting science data in the expected format and the instruments are fully functional,” Stone said via email. “The only remaining action is to reset the clock in the spacecraft’s data system that lost time while the memory bit was in the wrong state. The reset commands will be sent to the Voyager 2 in the next two weeks.”

The flipped or bad bit in the flight data system was likely caused by a cosmic ray that slipped by the radiation protection on the spacecraft. Since the computer stores information in ones and zeroes, a cosmic ray hit can change the value of a memory bit. The concern was that the flipped bit took place in an important location that could have a serious effect on the spacecraft, but fortunately, the problem was solved “easily.”

I say easily in quotes because of the complexities of diagnosing and fixing a spacecraft at such great distances. Since Voyager 2 is about 13.8 billion kilometers, or 8.6 billion miles, from Earth, it takes nearly 13 hours for signals to reach the spacecraft and nearly 13 hours for signals to come down to NASA’s Deep Space Network on Earth.

Hats off to the scientists and engineers at JPL for their efforts and dedication so we all can continue to follow Voyager’s continuing journey to interstellar space.

Sources: JPL, email exchange with Dr. Ed Stone, Planetary Blog.