NASA's Mars Reconnaissance Orbiter has nearly reached its destination, but its work is just about to begin. On March 10, the spacecraft will turn on its thrusters, allowing it to be captured by Mars' gravity. Over the course of the next six months, it will continue adjusting its orbit through a process called aerobraking, where the spacecraft skims through the Martian atmosphere, slowing it down a little bit each time. In addition to the high resolution images and scientific data it will capture, the spacecraft will help the rovers and future landers communicate back to Earth.
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NASA's Swift satellite is continuing to send back surprising information about gamma ray bursts. On February 18, 2006, it discovered something completely unique; a burst that originated 440 million light-years away and lasted about 30 minutes. This event is very similar to the more common bursts that have been seen in the past; however, it was about 25 times closer, and lasted 100 times longer than a typical burst.
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These images, of the Ausonia Mensa massif, were taken by ESA's Mars Express spacecraft. This region is a large remnant mountain, 3,700 metres (12,100 feet) high. It's covered by several large impact craters, some of which are partially filled with sediment, and in various stages of erosion.
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In late January, astronomers celebrated the creation of an artificial star in the nighttime sky. The star was created 90 km up in the atmosphere by a powerful laser projected out of the ESO's fourth 8.2m Unit Telescope of the Very Large Telescope at Cerro Paranal in Chile. This artificial star allows the telescope's adaptive optics system to compensate against the fluctuations of the Earth's atmosphere, and produce images as crisp and clear as if they were taken from space.
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If our Milky Way looked in the mirror, this is what it would probably see. This is a photograph of galaxy Messier 100, located about 60 million light-years away. It presents an intricate structure with a bright core, two large arms, and a pair of fainter spiral arms. Japanese amateur astronomer Shoji Suzuki and Italian astronomer Marco Migliardi recently discovered a Type-Ia supernova in M100 on February 4, 2006.
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Boston University astronomers announced today that they've found evidence that solar flares change the upper Martian atmosphere. The researchers found that when X-ray bursts from the Sun reach Mars, they cause the planet's ionosphere to produce additional ions and electrons - exactly the same situation was recorded simultaneously by satellites here on Earth. The measurements were made by NASA's Mars Global Surveyor as it transmitted data back to Earth.
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The Earth's magnetic field concentrates solar radiation into a series of regions called the Van Allen belts. Any spacecraft or astronauts passing through these regions must take precautions or be showered with radiation. But NASA scientists have learned that a "safe zone" between the belts actually moves around depending on the amount of solar activity reaching the Earth. The measurements were made using several meteorological satellites which periodically dipped into the Van Allen belts and through these safe zones.
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When President Bush announced his new Vision for Space Exploration in January 2004, he set NASA on a new course to return to the Moon, and maybe even set boots on the surface of Mars in the next few decades. Instead of a quick course change, NASA would work within a modestly increased budget to develop the new Crew Exploration Vehicle, while completing the International Space Station and retiring the Space Shuttle. Science, such as the Hubble Space Telescope, Mars rovers, and climate research wouldn't be affected.
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Pluto and its three moons were likely formed together when two large objects collided millions of years ago. Charon has been observed for decades, but the two new smaller moons, discovered last year, also orbit in the same plane as Charon and have a similar orbital resonance. It's even possible that Pluto has a ring system. Astronomers now believe that many Kuiper Belt Objects have multiple moons, and even higher order systems will probably be discovered in the years to come.
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This image of the lunar crater Billy was captured by the Advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft. With a diameter of 46 kilometres (29 miles), crater Billy is located on the southern fringes of the Oceanus Procellarum. The floor of Billy has been filled by basaltic lava with a very low albedo, leaving a dark surface. This image was taken on the 14th Jan. 2006, from a distance of about 1260 kilometres.
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NASA's Spitzer Space Telescope has uncovered a hot extrasolar planet orbiting a nearby star. Planet HD 189733b orbits its parent star only 63 light-years from Earth, making it the closest extrasolar planet ever detected directly. It moves in an extremely tight orbit - less than 3% of the distance from the Earth to the Sun - completing a tour around its star in just over 2 days. And it's scorching hot, reaching temperatures of 844 Celsius (about 1,551 Fahrenheit) on its surface.
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UK astronomers have used the Jodrell Bank Observatory to discover an entirely new class of objects. These new kinds of stars are similar to pulsars, as they produce brief radio flashes which only last for a few milliseconds. Unlike pulsars, however, they stay silent for much longer periods of time, ranging from 4 minutes to 3 hours. Astronomers think these objects build up energy over hundreds of rotations, and then release it in a single burst - and then build back up again.
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This false colour image of Saturn's moon Enceladus shows incredible features across its surface, invisible in natural colour. The bluish southern regions are deposits of large grains of poure ice, which show that the moon's southern hemisphere is relatively young compared to the meteor pounded northern hemisphere. Cassini took this photo on January 17, 2006 when it was 153,000 kilometers (95,000 miles) from Enceladus.
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Australian astronomers have used the powerful Gemini observatory to measure the amount of dark matter in the heart of galaxy NGC 3379. They made their estimate by observing 22 globular clusters near the galaxy's central halo, and then measured their distance from the galactic centre. They were then able to calculate how much dark matter in the galaxy's dark halo was nearby to keep them in this orbit.
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When stars near the end of their lives, they expel their outer layers into space. This gas expands and cools, and some of it condenses into grains of dust; eventually this dust comes together to form stars and planets. NASA scientists have built a stardust factory at the Goddard Space Flight Center to model what kinds of conditions are required to generate this dust. It turns out that stars can make this dust at much higher temperatures than previously believed.
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In ancient times, skywatchers knew of 5 planets: Mercury, Venus, Mars, Jupiter and Saturn. The fact that Earth was another planet didn't occur to anyone for a few more years. Uranus was discovered in 1781, Neptune in 1846, and tiny Pluto was finally located in 1930. That brought the total number of planets to 9. We were all raised to believe that there are 9 planets. That's it, case closed. Right? Wrong... maybe.
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The first astronauts wanted to be more than passengers in their spaceships. However, undertaking an active role meant that systems, interfaces and controls need be suited for human use even though the environment was completely unknown. Mary Jane Chambers and Dr. Randall Chambers in their book
Getting Off the Planet provide a first hand account of some of the challenges that were mastered in resolving this issue and in meshing human to machine. As they note, with judicious testing and training, there was much greater confidence in the success of all the space missions.
Greetings, fellow SkyWatchers! With the Moon exiting the early evening scene it's back to deep sky as we have a look at open clusters, supernovae, and protostars. The weekend serves up a galactic dish and a meteor shower to wash it down. Time to turn an eye to the sky, because...
Here's what's up!
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Since it's often hidden by the glare of the Sun, you don't get many chances to see Mercury. Well, now's your chance. From now until March 1, Mercury will be clearly visible in the west as twilight turns to night. Friday, February 24th will be the best night to look for Mercury, and a thin crescent moon will be close to the planet on March 1st. NASA's Messenger spacecraft is on its way to Mercury, and is expected to arrive in 2008. Until then, make sure you get outside, look west, and enjoy a view of this tiny planet.
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The iron meteorites whizzing around the Solar System are probably remnants of objects that helped form the Earth and the other rocky planets. When they fall down to Earth, scientists get an opportunity to study some of the primordial building blocks of our planet. Although many of the Solar System's asteroids are found in the asteroid belt, they probably emerged out of the same disk of planetary debris that formed the Earth, and then drifted out to their current location.
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Scientists at the University of Chicago have received their first samples of cometary dust from NASA's Stardust mission, which returned back to Earth in mid-January. The samples consist of several thin slices of a single dust grain, as well as a larger piece which can be sliced up even finer. Mission scientists believe that the spacecraft collected a total of 2,300 particles larger than 15 micrometres across (1/3rd the width of a human hair).
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Astronomers now know that the haze of the Milky Way is actually the combined light of millions of stars. The Milky Way has a similar haze in the X-ray spectrum, and that also seems to be coming from a multitude of point sources. Astronomers pooled together 10 years of observations from the Rossi XTE orbital observatory, and they were able to determine that the emissions are coming from a million white dwarf stars, and hundreds of millions of stars with active coronas.
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In orbit for more than a year and a half now, NASA's Cassini spacecraft is only just now getting around to imaging Saturn's northern hemisphere. It's winter in northern Saturn right now, and scientists want to know if the two hemispheres experience different weather patterns depending on the seasons. Cassini took this image on January 6, 2006 when it was 2.9 million kilometers (1.8 million miles) from Saturn.
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Astronomers have been puzzling over a mystery for a few years now, and they think they might have an answer. Everywhere you look, there's a diffuse glow of background X-ray radiation - but where's it coming from? Astronomers pointed the Chandra X-Ray Observatory at a patch of sky for a total of 23 days over a 2-year period, and resolved 600 separate point sources. This isn't a background glow at all, but the X-ray radiation from hundreds of millions of supermassive black holes, like the one at the heart of the Milky Way.
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There are many icons that represent the universe: brilliant stars, the rings of Saturn or something as familiar as Earth's own Moon. But for many, one of the images that best symbolizes the awe and mystery of deep space is the haunting beauty of the Sombrero Galaxy, also known as M-104.
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Mars' moon Phobos casts its shadow across the surface of the Red Planet in this photograph captured by ESA's Mars Express. Phobos is only 27 kilometres by 22 kilometres in size (17 x 14 miles), and it orbits Mars once every 7.5 hours. To an observer on the ground, this eclipse would look similar to one on Earth; however, Phobos would only cover about 20% of the Sun's surface. And it would be over quickly - the shadow moves at 7200 km/h (4400 mph).
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Cassini captured two of Saturn's moons in this image: Titan and Tethys. Titan is in the upper left, and is shrouded by a thick atmosphere that protects it from most impacts. Tethys, on the other hand, has no atmosphere, and has suffered numerious impacts, including the enormous impact that dug out the crater Odysseus. This image was taken on January 6, 2006, when Cassini was 2.7 million km (1.7 million miles) from Tethys, and almost double that distance from Titan.
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ESA's Mars Express spacecraft has spotted evidence of auroras over the night time side of Mars. These auroras make v-shaped structures of accelerated electrons and ions, similar to what we see here on Earth. Mars doesn't have a planetary magnetic field, so the discovery of auroras came as a surprise; however, it does have magnetic regions - the remnants of an old planetary magnetic field. Since Mars is always lit from our vantage point here on Earth, it required a spacecraft to find the auroras, which are only detectable at night on Mars.
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After 100 days of travel, ESA's Venus Express tested its main engine for the first time. The burn only lasted 3 seconds, and changed the spacecraft's velocity about 3 metres/second (10 feet/s). The engine test worked perfectly, and Venus Express was able to reorient itself after the burn, and correctly point its high-gain antenna back at Earth. The engine will be used again on April 11, when it will fire for 51 minutes, putting it into orbit around Venus.
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According to new research published by NASA scientists, Greenland's glaciers are losing ice at an accelerating rate. In the period from 1996 to 2005, the island's glaciers doubled the amount of ice they're shedding annually into the world's oceans. This acceleration is due to a global rise in temperature. Once Greenland's glaciers are all gone, scientists estimate world sea levels will have risen approximately 7 metres (23 feet).
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Our five senses are all we have to allow our brains to interact with the world outside our bodies. Space exploration relies almost entirely on one, the sense of sight. Space probes send us images of planets, moons and other objects which we then have to decipher as best we can. Richard Greenberg in his book
Europa, The Ocean Moon uses recent images of Europa, together with our understanding of celestial mechanics and plate tectonics, to unravel this little moon's mysteries. For Europa's biggest mystery is whether it harbours life who may be looking right back at us from their own little world.
In this beautiful Cassini photograph perfectly lined up along Saturn's ringplane, it's possible to see three of the planet's moons: Dione is at the left, Prometheus is in the centre, and Epimetheus is on the right. This image was taken on January 2, 2006, when Cassini was 2.8 million kilometers (1.7 million miles) from Saturn.
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Japan's recently launched Advanced Land Observing Satellite (ALOS) has sent back its first pictures of Earth - Mt Fuji and its surrounding towns. The satellite was launched on January 24, 2006, and it contains three onboard instruments for Earth observation. One instrument is called the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM). It's capable of taking many 3-D images quickly and accurately.
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If humans are going to be spending longer periods in space, on the Moon, or even on Mars, it's just a matter of time before they'll need surgery. Can delicate surgery even be done in the weightlessness? Doctors from NASA and the Canadian Space Agency think so. They're working out a series of experiments where surgeons will attempt procedures in weightless situations, like underwater or in a special aircraft that simulates weightlessness. They believe that future missions will have at least one surgeon and several of the crew will be trained in surgical techniques as well.
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At first glance, this hazy view of Saturn seems largely featureless, but if you look closely, you can see great oval-shaped storms churning through the planet's clouds. The lines extending away from the storms indicate that there isn't much horizontal mixing between layers. This photograph was taken on January 2, 2006 when Cassini was 2.8 million kilometers (1.7 million miles) from Saturn.
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Spitzer has uncovered an unusual pair of colliding galaxies whose hearts are surrounded by tiny crystals that resemble crushed glass. These crystals look like sand, and were probably shed from massive stars before and while they exploded as supernovae. Although these crystals have been seen in the Milky Way, this is the first time they've been found outside our galaxy. They won't last long, however. Scientists think the crystals will get heated up again and again by multiple supernova blasts and eventually melt back into a shapeless form.
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Astronomers have used the light from a distant quasar to discover a metal-rich hydrogen cloud that would have otherwise been invisible; the quasar is 9 billion light-years away, but the cloud is only 6.3 billion light-years away. By analyzing the spectrum of this galaxy, astronomers have discovered that it contains 4 times more metal than what's contained in our Sun. If more of these clouds are discovered, it might help account for why the Universe seems to contain less metal that cosmologists have predicted it should.
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When NASA's Chandra X-Ray Observatory took this photograph of the supernova remnant Puppis A, it revealed a how a cloud of nebula is being torn apart by the shockwave from the supernova explosion. The oval structure of the cloud with an empty region inside, closely matches experimental simulations done here on Earth, where a shockwave blasts past a cloud of vapourized copper. The cloud briefly compresses, and then rapidly expands leaving a cavity inside.
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NASA astronomers have discovered an unusual solar system about 500 light-years away where the inner planets are going one direction, and the outer planets are going in the opposite direction. This newly forming system is quite different from our own Solar System, where the planets and the Sun all turn in the same direction. It's possible that the system formed from two different clouds of material, which were rotating in opposite directions.
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Scientists are tracking a gigantic electrical storm raging on the surface of Saturn. This storm is the size of the United States, and the most powerful of its type ever seen. The origin of these storms is unknown, but researchers think it might have something to do with Saturn's warm interior. Cassini is expected to get much closer to Saturn in the next few weeks, so scientists will get a much better view.
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A team of French scientists have successfully recreated the structure of primitive interstellar particles in their laboratory. This material is a silicate glass that contains embedded metal and suphides, and astronomers believe it's created in protostellar nebulae. The team heated up particles of olivine under high vacuum and temperatures ranging between 500 to 700ºC, and the resulting material closely matched this interstellar dust. This helps scientists understand some of the processes that occur in stellar nebulae.
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Cassini was only 14,500 km (9,000 miles) from Saturn's moon Telesto when it took this photograph. Telesto is tiny, only 24 km (15 miles across), and it appears to be covered in fine, icy material that obscures ancient meteor strikes. This is quite different from many of Saturn's other moons, which look quite pockmarked in comparison.
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Researchers at the University of St. Andrews and the Free University of Brussels think they have a solution that "fine-tunes" Einstein's groundbreaking theory of gravity to help account for the effect of dark matter. Dr Hong Sheng Zhao and Dr Benoit Famaey have created a new formula that allows the strength of gravity to vary over galactic distances, perfectly matching observations made by astronomers.
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One of the best places to look for life on Mars might be underneath its surface, in vast underground fields of ice. A new mission is being considered that would smash a projectile at high speed into the Martian surface, to reveal the subsurface environment. The Tracing Habitability, Organics and Resources (THOR) project could launch in 2011, and would dig a crater 10 metres (30 feet) deep when it struck. An observer spacecraft would watch the debris plume, looking for any evidence of life.
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This Cassini view of Saturn's moon Titan shows its hazy atmosphere. The photo was taken by combining red, blue, and green spectral filter photographs and has been greatly contrast-enhanced to show some subtle structures in the northern hemisphere. Cassini captured this image on December 26, 2005 when it was approximately 193,000 kilometers (120,000 miles) from Titan.
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Scientists from Ohio State University think they know what created the famous "Man on the Moon" feature. They think that a large object impacted the Moon on the far side, which sent a shock wave through its core and fractured the opposite side. The team used gravity fluctuations measured by NASA's Clementine and Lunar Prospector spacecraft to map the Moon's interior. The data shows that the asteroid impact was so catastrophic, the resulting scar passes clear through the Moon's mantle and core.
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