Postcards from Mars 'reveal water'

NASA's latest visitor to Mars has sent its first postcards home - and they offer clear evidence that it is sitting on top of a huge mass of water ice. The $460 million Phoenix probe's pin-sharp pictures of the landscape in a far north of the Red Planet show a strange honeycomb pattern of polygons in the permafrost. NASA say the polygons are a phenomenon observed in our own Arctic. And a British Mars expert told Skymania News that they are a clear sign that water - essential for life - lies beneath the rust-coloured soil. Dr John Murray, of the Open University, said the honeycomb pattern was evidence of water disappearing into the martian atmosphere in a process akin to evaporation called sublimation. He said: "They look very much like dehydration cracks where the surface has dried up - like the cracks in a dried-up puddle of mud. They are a clear sign that there has been water at the surface and so there are likely to be vast reserves of it frozen as ice just inches beneath the surface. "This should be the bottom of an old ocean because the whole northern region of Mars was covered in water two or three billion years ago. All the ancient catastrophic floods on Mars flooded into theis area so it should be like the bottom of the sea." Dr Murray, a researcher with the Mars Express mission, believe that the European orbiter has photographed the pattern of Arctic-style pack ice, an indication of the ancient martian seas, in a region called Elysium. NASA's mantra has long been to "follow the water". Phoenix is set to touch it for the first time by actually digging through the soil to collect samples of water ice. Dr Murray said: "That is the most exciting thing, that we will soon be holding martian ice in our hands - or in the robot's hands anyway." NASA has been at pains to point out that Phoenix is not designed to discover life itself. But scientists are pointing out that it could spot them because it carries two powerful microscopes. Scientists at Imperial College London engineered the special surface that will hold samples of soil so that they can be examined with a powerful microscope. Dr Tom Pike, of Imperial, said: "It is very difficult to predict what we might find, but if you wanted to look for signs of the earliest forms of past or present life we will be the first to look closely enough." Another UK member of the Phoenix team is David Catling from Bristol University who will investigate weather in the polar region of Mars. NASA has released another astonishing photo, seen above, that shows Phoenix parachuting towards Mars. Taken from the Mars Reconnaissance Orbiter, it is the first time a probe has been pictured landing on another world. • What do you think? Skymania welcomes your comments and views. You can support this site by visiting Skymania's stores in the USA, the UK, Canada and France. They are powered by Amazon so you can buy with confidence. ©PAUL SUTHERLAND, Skymania.com

Success! Phoenix lands safely on Mars

Space scientists are celebrating after their latest Mars probe survived a perilous landing on the Red Planet to begin a mission to seek out clues to life. NASA's $460 million Phoenix craft touched down safely at at 7.53 pm PDT (12.53am UK time). It landed 68 degrees north in the martian arctic region, ready to dig deep into the soil to touch the frozen water for the first time ever. Back at mission control in Pasadena, scientists clapped, cheered and hugged each other. Then they waited for the first pictures of its icy terrain which were not expected to start arriving until at least an hour after landing. Phoenix, weighing a third of a ton and the size of a pick-up truck, had been cruising right on course to reach a region never visited before, called the Green Valley in Vastitas Borealis. Frst it dumped the cruise stage that carried it on its 422 million mile voyage since launch in Florida last August. Then, at 12.46am, it dived into the thin martian atmosphere at 12,750mph, its heat shield reaching a fiery 1,450 C. Other American and European probes already orbiting Mars tracked its descent. Slowing to 1,000mph, the craft jettisoned its heat shield, and opened its parachute and landing legs. Then, just over 1,000 yards up, it fired 12 retro rockets to slow it to less than 6mph for landing seconds later. The probe then stayed quiet for 15 minutes, waiting for dust churned up by the landing to settle before opening its solar panels. The manouvres were fraught with danger. A previous attempt to land like this failed in 1999 when NASA's Mars Polar Lander shut down its rockets too soon, believing from the vibrations that it had already landed. Phoenix became the first spaceprobe to use the social chat network Twitter on the internet. Members of the team posted regular updates of its progress. In the next few days, Phoenix will dig 20 inches down into the permafrost with a robotic drill to look for water ice beneath the soil. Then it will analyse samples in its own on-board laboratory to find organic chemicals and check whether conditions could ever have supported life. The probe is not expected to survive more than six months before the martian winter sets in again and freezes the probe's equipment and solar batteries. But if it does, it will be awoken in the spring. Photo: One of the first colour pictures from Phoenix of its surroundings. More here • What do you think? Skymania welcomes your comments and views. You can support this site by visiting Skymania's stores in the USA, the UK, Canada and France. They are powered by Amazon so you can buy with confidence. ©PAUL SUTHERLAND, Skymania.com

Phoenix heads for Mars landing

NASA's latest space probe to Mars, Phoenix, is heading for a landing in the far north of the planet this weekend. If all goes well, it will dig into the permafrost to look for the basic ingredients for life. Catch up with the latest news in the Mars section of Skymania.

Exploding star is caught live

Astronomers are celebrating after watching the spectacular death of a star happen right before their eyes. For the first time ever, they had ringside seats to witness the cosmic explosion, called a supernova, live. Alicia Soderberg and Edo Berger were monitoring another blast in a distant spiral galaxy called NGC 2770 in the constellation of Lynx, the Wild Cat. But as they examined its dull glow, using a space telescope called Swift that views with X-ray eyes, an extremely bright light suddenly flared in the same galaxy, 90 million light-years from Earth. Supernova 2008D seen exploding in X-ray light, left, and at visual wavelengths a few days later. The earlier supernova is labelled too. The pair, from America's Princeton University, became the first astronomers to catch a star in the act of exploding. Usually they are not found until days or weeks after the event. The pair quickly alerted other scientists including UK researchers. Telescopes around the world and in space were turned on the cosmic suicide. Reports of their observations of the supernova, labelled SN 2008D, are published in this week's issue of the journal Nature. The blast, seen on January 9, actually happened 90 million years ago when dinosaurs walked the Earth. Astronomers are fascinated by supernovae because they collapse into neutron stars where a thimbleful of matter would weigh 100 million tons. Sometimes they even turn into black holes. A box of fireworks ready to explode in our own Milky Way was reported earlier this year. Dr Kim Page of the University of Leicester, who led the X-ray analysis, said: "This observation is by far the best example of what happens when a star dies and a neutron star is born." Colleague Dr Paul O'Brien, of Leicester, said: "Understanding supernovae is important as these nuclear furnaces make the heavy elements from which planets like ours form." Photo: Nasa/Swift Science Team/Stefan Immler. • What do you think? Skymania welcomes your comments and views. You can support this site by visiting Skymania's stores in the USA, the UK, Canada and France. They are powered by Amazon so you can buy with confidence. ©PAUL SUTHERLAND, Skymania.com

Universe shines twice as bright

The universe is shining twice as brightly as previously thought, astronomers have discovered. A team of British, Australian and German scientists found that half the light is being obscured by clouds of dust. Astronomers have long been aware that much of the universe is made up of dust. But they had not realised the extent to which it was masking what we see. The team was led by Dr Simon Driver of the University of St Andrews, in Scotland. He said: "For nearly two decades we've argued about whether the light that we see from distant galaxies tells the whole story or not. "It doesn't. In fact only half the energy produced by stars actually reaches our telescopes directly. The rest is blocked by dust grains." The dust absorbs starlight, then re-emits it in a glow. Astronomers realised their old ideas about the universe were flawed because the dust seems to be emiting more energy than possible with the stars known to exist. Dr Driver added: "You can't get more energy out than you put in so we knew something was very wrong. Even so, the scale of the dust problem has come as a shock. It appears that galaxies generate twice as much starlight as previously thought." The team made their discovery using data from the Millennium Galaxy Catalogue, a high-resolution catalogue of 10,000 galaxies assembled by Driver and his team using the Isaac Newton Telescope in the Canary Islands and others. They used this to test a new model for dust distribution in galaxies developed by scientists in the UK and Germany which allowed them to calculate precisely the fraction of starlight blocked by the dust. The key test that the new model passed was whether the energy of the absorbed starlight equated to that detected from the glowing dust. "The equation balanced perfectly," said Dr Cristina Popescu, of the University of Central Lancashire, who helped draw up the model. "For the first time we have a total understanding of the energy output of the Universe over a monumental wavelength range." The photo shows the spiral galaxy NGC891 edge on, revealing a dark lane of dust. Photo by Robert Gendler. You can see more great photos of galaxies here. • What do you think? Skymania welcomes your comments and views. You can support this site by visiting Skymania's stores in the USA, the UK, Canada and France. They are powered by Amazon so you can buy with confidence. ©PAUL SUTHERLAND, Skymania.com

Missing supernova is found at last

One of the biggest blasts in our galaxy went off without anyone spotting it because it was hidden behind a cloud of dust, astronomers revealed today. The explosion, a suicidal star called a supernova, was brighter than all the stars in the Milky Way combined and might normally have been visible in daylight. However, Victorian stargazers saw nothing of the blast around 150 years ago due to a dense region of obscuring dust and gas. Remnants of its expanding shell have finally been identified by UK scientist Dr Dave Green, of the University of Cambridge, with colleague Dr Stephen Reynolds of North Carolina State University. Experts had often remarked on the fact that no supernova had been recorded within our galaxy since the 17th Century, although they are regularly spotted going off in other galaxies deep in the universe. The two scientists compared an X-ray "photo" of the blast's remains taken using the Chandra satellite in 2007 with another image made with a group of US radio telescopes called the Very Large Array in 1985. They found the supernova remnant, called G1.9+0.3, had expanded at an unprecedented rate, growing in size by 15 per cent in just 23 years. Working backwards, they confirmed that the blast that created them must have happened about 150 years ago. This finding makes the supernova easily the youngest known in our Milky Way galaxy. Although its precise distance is not known, the astronomers believe it lies near the centre of the galaxy. Radio waves and Xrays are able to penetrate dense clouds of dust whereas light cannot. Dr Green said: "The discovery that G1.9+0.3 is so young is very exciting. It fits into a large gap in the known ages of supernova remnants, and since it is expanding so quickly, we will be able to follow its evolution over the coming years." Details of the discovery will appear in the journal Monthly Notices of the Royal Astronomical Society. Planets like our own are believed to form from dust left by supernova blasts. The closest supernova to us in recent years was seen to explode in 1987 in a satellite galaxy of the Milky Way called the Large Magellanic Cloud. It became easily visible with the naked eye and its debris was later pictured shining like a ring of pearls. Last month, astronomers identified clusters of other candidates for supernovae. • What do you think? Skymania welcomes your comments and views. You can support this site by visiting Skymania's stores in the USA, the UK, Canada and France. They are powered by Amazon so you can buy with confidence. ©PAUL SUTHERLAND, Skymania.com

Amateurs monitor storm on Saturn

NASA scientists have acknowledged the value of amateur observations in supporting their exploration of Saturn. They are using studies by hobbyists to help keep track of a powerful thunderstorm that has been raging for five months on the ringed planet. The storm, thousands of miles wide, produces lightning bolts 10,000 times more powerful than those here on Earth. The spaceprobe Cassini, whose mission was extended last month, has been taking colour pictures of the storm, like those shown here. But when Cassini is on the other side of Saturn, the scientists have turned to modern CCD images - taken with exotic versions of the webcam - to keep up with developments. Georg Fischer, of the University of Iowa, has been studying electrostatic discharges from the storm which produce radio signals. He said: "Since Cassini's camera cannot track the storm every day, the amateur data are invaluable. I am in continuous contact with astronomers from around the world." The new storm, first detected on November 27 last year, is raging in Saturn's southern hemisphere, in a region that has been dubbed Storm Alley by mission scientists, following previous bad weather there. You can listen to a previous storm here. Fischer said: "The electrostatic radio outbursts have waxed and waned in intensity for five months now. We saw similar storms in 2004 and 2006 that each lasted for nearly a month, but this storm is longer-lived by far. And it appeared after nearly two years during which we did not detect any electrical storm activity from Saturn." Ulyana Dyudina, of the Cassini imaging team, said: "In order to see the storm, the imaging cameras have to be looking at the right place at the right time, and whenever our cameras see the storm, the radio outbursts are there." The scientists hope their studies will help them learn what causes the amazing storms. They have also been fascinated by a monster storm over Saturn's south pole. • What do you think? Skymania welcomes your comments and views. You can support this site by visiting Skymania's stores in the USA, the UK, Canada and France. They are powered by Amazon so you can buy with confidence. ©PAUL SUTHERLAND, Skymania.com