Hubble presents some smash hits

Pictures of the week must be Hubble's latest release which you could call a crash course in the phenomenon of colliding galaxies. The space telescope team have isssued a collection of 59 new colour images of these vast star cities running into each other to mark the 18th anniverary of Hubble's launch. They show a fascinating array of intricate structures as the galaxies interact, and tidal effects change the forms of their wisps and loops. Contrary to what one might imagine, galactic collisions do not result in enormous explosions. They are not like a cosmic car crash. The reason is the vast distance between the stars which means that they simply pass each other as they sail through space in different directions. The Hubble team note that interacting galaxies are found throughout the universe and can trigger bursts of star formation or even form new galaxies. Such mergers, which were more common in the early universe than today, are thought to be one of the main driving forces for cosmic evolution. They switch on quasars, spark frenetic star births and prompt explosive stellar deaths. Even apparently isolated galaxies will show signs in their internal structure that they have experienced one or more mergers in their past, say the astronomers. The merging galaxies captured in the released series of images are snapshots of different moments in the long interaction process. Our own Milky Way contains the debris of the many smaller galaxies it has encountered and devoured in the past, and it is currently absorbing the Sagittarius dwarf elliptical galaxy. In turn, it looks as if our Milky Way will be absorbed by its giant neighbour, the Andromeda galaxy. They are rushing towards each other at a staggering 500,000 km per hour - yet the collision will still not happen until around two billion years time, forming a new super galaxy which wags have dubbed Milkomeda. Picture: NASA, ESA and the Hubble Heritage Team. • 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

NASA challenge boy, 13, on asteroid

NASA has got caught up in an astonishing clash with a 13-year-old schoolboy over the threat of an asteroid impact, though they were reacting to some rather wild press reports rather than the lad's own dubious maths. The German student calculated that a 350-yard wide space rock called Apophis has a one-in-450 chance of colliding with the Earth in 2036, contradicting NASA's own estimate that the odds are a low one-in-45,000. Nico Marquardt based his results on the possibility that the deadly asteroid could smash into satellites orbiting the Earth, deflecting its course, as it makes a previous close pass on Friday 13th of April, 2029. Apophis is expected to come inside the orbits of communications satellites such as those used by Sky TV. But NASA say the chance of any collision is "exceedingly remote". In an unprecedented statement, NASA's Jet Propulsion Laboratory in California said it "has not changed its current estimates for the very low probability (1 in 45,000) of an Earth impact by the asteroid Apophis in 2036." The space scientists added: "Contrary to recent press reports, NASA offices involved in near-Earth object research were not contacted and have had no correspondence with a young German student, who claims the Apophis impact probability is far higher than the current estimate. "This student's conclusion reportedly is based on the possibility of a collision with an artificial satellite during the asteroid's close approach in April 2029. However, the asteroid will not pass near the main belt of geosynchronous satellites in 2029, and the chance of a collision with a satellite is exceedingly remote. "Therefore, consideration of this satellite collision scenario does not affect the current impact probability estimate for Apophis, which remains at 1 in 45,000." The US-based Planetary Society has put up a $50,000 prize for whoever comes up with the best scheme to tackle the threat that Apophis poses. Last year, scientists revealed they had discovered the type of rock that makes up Apophis - a "know your enemy" finding that could help them deal with it. Picture: A NASA artist's impression of an asteroid impact. • 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

Cassini gets more time to explore Saturn

NASA today extended the life of one of its most successful missions to the planets - the exploration of Saturn and its moons. The fantastic voyage of the unmanned Cassini spacecraft, supported by European space scientists, was due to come to an end in July. But the two-year extension is expected to deliver a stream of new discoveries about the ringed planet as Cassini makes 60 more orbits of Saturn and its family. Cassini was launched in 1997 but did not reach Saturn until 2004 after a journey of 2.2 billion miles across the solar system. One of its earliest successes was to send a separate probe called Huygens to land on Saturn's biggest moon, Titan. UK scientists played a major role in the Titan triumph with Professor John Zarnecki, of the Open University at Milton Keynes, in charge of experiments on the surface. Titan is the only moon to have a dense atmosphere. Scientists believe its organic chemistry resembles that on a young Earth and that life could be coming into existence in its seas of methane. Cassini also discovered geysers of water-ice spewing into space from another moon, Enceladus, and helping to stock up the particles in Saturn's spectacular rings. Cassini program manager Bob Mitchell, of NASA's Jet Propulsion Laboratory, in California, said: "The spacecraft is performing exceptionally well and the team is highly motivated, so we're excited at the prospect of another two years." NASA has a history of lengthy planetary missions. A probe called Galileo spent eight years orbiting the biggest planet Jupiter before being deliberately sent crashing into its clouds in September 2003. And two robot rovers, Spirit and Oportunity, are still trundling about on the surface of Mars after arriving early in 2004 for missions each designed to last 90 days. Picture: Saturn imaged by Cassini. (NASA) • 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

Brown dwarf is the coldest star known

Astronomers have discovered the coldest star ever found - and believe it is a "missing link" between suns and planets. The star, known as a brown dwarf, lies only 40 light-years away from Earth, meaning we are seeing it as it was in 1968. Despite its proximity, the star, dubbed CFBDS0059, shines dimly because its temperature is only around 350 C. It is between 15 and 30 times the size of Jupiter, the biggest planet in the solar system. The new star was found in the constellation of Cetus, the whale, by an international team of French and Canadian astronomers using giant telescopes in Hawaii and Chile. The team, who will announce their discovery in the journal Astronomy & Astrophysics, suggest that the star be considered the prototype of a new class of brown dwarfs, to be called Y dwarfs. Planets such as Jupiter and Saturn are called gas giants because they are not rocky worlds like the Earth. It appears that they may be more closely related to cool stars that failed to burn as intensely as the sun. The Y dwarf CFBDS0059 looks more like a giant planet than the previously known and hotter L and T classes of brown dwarf. Y dwarfs therefore become the coldest stellar objects known and a missing link between stars and giant planets. Because of their low mass, the temperatures at the cores of brown dwarfs is not high enough to maintain thermonuclear fusion reactions over a long time. Unlike the sun, which spends most of its lifetime burning hydrogen and keeping a constant internal temperature, a brown dwarf gets steadily colder and colder after it is formed. The first brown dwarf was not spotted until 1995. The discovery of an even closer one, 12.5 light-years away, was announced two years ago. Stars and planets are both believed to form from swirling clouds of gas and dust. Picture: A photo of the field of stars containing the brown dwarf dubbed CFBDS0059. It is the deep red object in the upper part of the photo. (© Canada-France-Brown-Dwarf-Survey 2008). • 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

Amazing new pictures from Mars

Stunning new images of Mars have been released by Nasa, including close-ups of its larger moon Phobos. The one we show here is a general colour view of the tiny world - thought to be a captured asteroid, with its fascinating craterlets and grooves. But Nasa also released a 3D image, viewable if you have blue-and-red glasses, taken by the HiRise camera on the Mars Reconnaissance Orbiter. Rather than using two cameras to take the twin exposures necessary, scientists simply took two photos ten minutes apart to achieve a similar effect. The Phobos pictures reveal a phenomenon called Marsshine which is the equivalent to Earthshine on the Moon. Just as sunlight reflected back from the Earth illuminated the dark disk of a "New" Moon, so the light from Mars lights up craters on Phobos that would otherwise be in darkness. Professor Alfred McEwen, HiRise principal investigator at the Lunar and Planetary Laboratory at the University of Arizona, said: "Phobos is of great interest because it may be rich in water ice and carbon-rich materials." Another amazing picture from HiRise shows sand dunes that look so perfectly sculpted that you could be forgiven for thinking they were designed by artistic aliens. But the dunes, within the Hellespontus region of Mars, are simply the result of powerful winds blowing from west to east (left to right in the picture) according to the experts. Prtevious wonderful images from Mars Reconnaissance Orbiter have included a look back at the Earth and Moon plus clear pictures that put a damper on claims that fresh water is still flowing on Mars. • 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

Jules Verne docks with space station

A European spacecraft finally docked with the International Space Station today in a landmark event for the orbiting outpost. The successful link-up by the space tug Jules Verne was carried out using automatic laser-guided systems, boosting Europe's role as a major player in the ISS project. There were cheers and a round of applause at mission control in Toulouse as the successful mating occurred. Although the craft, called an Automated Transfer Vehicle, is currently designed to carry cargo, it could eventually be adapted to become a manned spaceship. The ship looked like something out of Star Wars thanks to its four long solar panels stretching out in the shape of an "X". For several minutes, it sat 62ft away from its target awaiting the final command to approach. Then space scientists at Houston, Moscow and Toulouse, all watched intently as the 20-ton spacecraft closed in silently for a perfect docking at 3.45 pm UK time with the Russian Zvezda service module of the ISS. Both spacecraft were zipping around the Earth at nearly five miles per second in an amazing example of formation flying. But their approach was carried out slowly to avoid any risk of a collision that could have jeopardised the space station and its astronauts' lives. The craft had already made two flawless approaches to the orbiting outpost this week to demonstrate that its automatic laser-guided navigation systems were working well. During dress rehearsals it also responded perfectly to an "Escape" command from astronauts aboard the space station, 212 miles above the Earth, by withdrawing to a safe distance. The Jules Verne is carrying 1,100 lbs of food, fresh clothes for astronauts on the space station plus a hardback copy of From The Earth To The Moon by sc-fi writer Jules Verne. Also on board are 300 lbs of spare parts for Europe's new Columbus module which was attached to the space station in February. Space station astronauts will enter the Jules Verne to unload its cargo and fill it with rubbish during its four-month visit. The craft's thrusters will also be used several times to boost the space station to a higher orbit to counter a gradual downward drift. The Jules Verne was launched way back on March 9 but has had to wait patiently in space while the shuttle Endeavour arrived and completed its own mission to the space station. In August, the ship will undock and be steered to burn up over the Pacific. Picture: The Jules Verne pictured from the ISS during a docking rehearsal. (ESA). • 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

Black hole lurks in famous cluster

The Hubble space telescope has found a black hole in one of the brightest star clusters in the sky. The discovery has forced scientists to reconsider the nature of Omega Centauri which is easy to spot from countries in the southern hemisphere. Astronomers had thought the object was an unusual example of a globular cluster - tightly packed balls of hundreds of thousands of stars that are found orbiting galaxies like the Milky Way. Now they believe that Omega is probably a dwarf galaxy itself but one that has been stripped of its outer stars. The new discovery was made with the Advanced Camera for Surveys combined with data from a spectrograph on the Gemini South telescope in Chile. They show that Omega Centauri appears to harbour a medium-sized black hole in its centre - that is one of moderate mass. Eva Noyola, of the Max-Planck Institute for Extraterrestrial Physics in Garching, Germany, led the team that made the discovery. She said: "This result shows that there is a continuous range of masses for black holes, from supermassive, to intermediate-mass, to small stellar mass types." Omega Centauri is visible with the naked eye as a blur almost the size of the full moon and is a favourite target for stargazers with backyard telescopes. It lies 17,000 light-years away from Earth and was first listed in a catalogue drawn up by Ptolemy nearly two thousand years ago. The English astronomer John Herschel was the first to identify it as a globular cluster in the 1830s. Astronomers are still trying to observe more closely a black hole at the centre of our own Milky Way. Circumstantial evidence has also already been found of a black hole in a satellite galaxy of our own. Picture: A photo of the mysterious Omega Centauri. (NASA/ESA) • 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

Watching shooting stars on Mars

British astronomers have, for the first time, detected a shower of shooting stars on another planet. They checked records from a space probe orbiting Mars to catch meteors streaking through its thin atmosphere. The scientists, from Armagh Observatory, first calculated the dates when Mars' path around the sun would cross the trails of debris left by comets. Six possible showers were identified. The team found Mars' orbit intersected with that of Comet du Toit-Hartley in April 2003 and March 2005. The Armagh team then checked those dates with records from the Mars Global Surveyor satellite and found it had recorded flashes in the Red Planet's upper atmosphere. Dr Apostolos Christou will describe the fascinating results at the National Astronomy Meeting in Belfast today. He said earlier: "Just as we can predict meteor outbursts at Earth, such as the Leonids, we can also predict when meteor showers are going to occur at Mars and Venus. "We believe that shooting stars should appear at Venus and Mars with a similar brightness to those we see at Earth. However, as we are not in a position to watch them in the Martian sky directly, we have to sift through satellite data to look for evidence of particles burning up in the upper atmosphere." Observations of meteor showers help astronomers learn more about the history of comets which come from the depths of othe solar system. About four times more comets fly close to Mars than the Earth, a high number of them in orbits tied to the planet Jupiter, and so scientists believe Mars offers a major opportunity to understand them. Flashes have been spotted before as meteors struck the Moon where there is no atmosphere to burn them up. It is a project that amateur astronomers can take part in. Picture: How Mars Global Surveyor looks orbiting the Red Planet. (NASA/JPL-Caltech). • 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

Here comes a solar tsunami

A pair of satellites have recorded for the first time a massive explosion blasting its way from the depths of the Sun. The solar tsunami resembled a tidal wave on Earth but travelling at speeds of well over half a million miles an hour. Such blasts can hurl electrically charged material at the Earth, threatening communications satellites, power grids and even the lives of astronauts. The tsunami bursting out of the Sun's lower atmosphere - called a coronal mass ejection - was captured by Nasa's twin Stereo spacecraft which produce 3D images of our home star. The event, which happened on May 19 last year, will be reported to the National Astronomy Meeting in Belfast today. The observations were made by a team from Trinity College, Dublin. Yesterday we told how another team has mapped in detail, the solar corona. Team member David Long said: "The energy released in these explosions is phenomenal, about two billion times the annual world energy consumption in just a fraction of a second. In half an hour, we saw the tsunami cover almost the full disc of the Sun, nearly a million kilometres away from the epicentre." The Stereo instruments monitor the Sun at four wavelengths, which allowed observers to track the tsunami as it travelled through different layers of the solar atmosphere. But tracking its path has raised new questions for astronomers to answer. Fellow researcher Peter Gallagher said: "To our surprise, the tsunami seems to move with similar speed and acceleration through all the layers. As the chromosphere is much denser than the corona, we'd expect the pulse there to drag. It’s a real puzzle." Despite this, the team hope that results from Stereo and other sun-watching satellites will soon help them to identify the cause of coronal mass ejections. Picture: A single Stereo image of another explosion on the Sun. (Nasa). • 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

Astronomers find supernova factories

Astronomers have discovered two stores of cosmic firecrackers deep in the galaxy, they will reveal today. The rare clusters contain 40 ancient stars all primed to explode as supernovae - the biggest blasts seen within the Milky Way. Both star clusters are around 20,000 light-years away in a straight region called the Galactic Bar which runs across the spiral pattern of our home galaxy. They lie 800 light-years apart. The stars are Red Supergiants right at the end of their life cycles. However, it is impossible to predict exactly when they will be seen to explode. Since they lie so far away, it is possible that some have aleady erupted and the light of their blasts is still racing across space to reach us. A supernova briefly becomes as bright as all the billions of other stars in the galaxy combined as it blows itself to pieces. Dr Ben Davies will announce the discovery of the clusters, in the constellation of Scutum, the shield, today at the National Astronomy Meeting in Belfast organised by the Royal Astronomical Society. He said yesterday: Red Supergiants, or RSGs, represent the final brief stage in a massive star's lifecycle before it goes supernova. They are very rare objects, so to find this many in the same place is remarkable. "Together they contain 40 RSGs, which is nearly 20 per cent of all the known RSGs in the Milky Way. These stars are all at the brink of going supernova." Cluster 1 contains 14 RSGs and is 12 million years old. Cluster 2 contains 26 RSGs and is 17 million years old. Massive stars are rarely observed because they burn their fuel up very quickly. RSGs are rarer still because they are only a brief period of that short life cycle. Dr Davies, of the Rochester Institute of Technology, New York, added: "The next supernova could go off in one of these clusters at any time. We estimate that it's about 5,000 years between explosions for these clusters and we can see the remnants of a supernova that went off around 5,000 years ago. That means that the next one could be any time between today and 7008 AD." The team first spotted the clusters in a survey of the galaxy made by Nasa's heat-seeking Spitzer Space Telescope. Their exact positions were then pin-pointed using a giant telescope on Hawaii. It is hundreds of year since a supernova was seen in our own Milky Way but they are regularly spotted in distant galaxies since there are so many of them. A supernova in a satellite galaxy of the Milky Way 21 years ago later revealed a stunning ring-of-pearls effect. Picture: One of the clusters spotted by the team. • 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

X-ray scan maps Sun's corona in 3D

Scientists have used a medical X-ray technique on their biggest ever "patient" - the Sun. They used the same method used for CAT scans to produce the first detailed map of the structure in its outer atmosphere. This region, called the corona, is the ghostly glow that can be seen around the Sun during a total eclipse. It produces a force called the solar wind, a stream of electrically charged particles that blow out through the solar system. The medical technique, called tomography, takes images from many different angles to build up a 3D map of a patient's body for doctors. Dr Huw Morgan, of the University of Aberystwyth, used it instead on images recorded with a satellite called Soho that constantly monitors the Sun. He will present his results today at a gathering of space scientists, the National Astronomy Meeting, in Belfast, organised by the Royal Astronomical Society. Dr Morgan, who worked with colleagues at the University of Hawaii, said: "This is a breakthrough for scientists trying to understand the corona and the solar wind. "We've been attempting to apply tomography to the solar corona for more than 30 years but it's proved very difficult and very inaccurate until now. The new technique that I've developed is only in its infancy but shows great potential for areas of research like space weather." Space weather includes dramatic explosions on the Sun that can send material hurtling towards Earth, threatening communication satellites, power grids, and even the lives of astronauts. Mapping the corona is seen as a major step towards understanding and predicting these storms. Other new Sun-watching satellites include Hinode and Stereo which are bringing us remarkable new images of our home star. Picture: A Soho satellite image of the Sun's corona. (ESA/Nasa) • 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

Planet hunters find ten new worlds

Two planet-hunting observatories built in the UK with the help of eBay have discovered ten new worlds in just six months. It brings their overall tally to 15, making them the most successful discovery instruments in the world. The observatories are each made up of a battery of eight cameras which scan the sky for flickers in starlight indicating the planets' existence. Astronomers had to turn to the auction site to track down 13 lenses, costing £4,000 each, after they learned that Canon no longer made them. News of the impressive tally by the observatories in the Canary Islands and South Africa will be revealed to astronomers meeting in Belfast today. The sky survey project, called SuperWASP - short for Super Wide Angle Search for Planets - watches millions of stars every night. More than 270 so-called extrasolar planets have been discovered orbiting other stars since the first was found in the early 1990s. Most were detected by a wobble in the star's position due to the planet's gravitational tug on it. SuperWasp uses a different method, watching for a tiny dip in the star's brightness caused by a Jupiter-sized planet passing in front of it. Each observatory is kitted out with the specially-built digital cameras which cost £30,000 each and were made by Andor Technology in Belfast. Together they cover an area of sky 250 times the size of the Full Moon. Complex computer software constantly checks the brightness of every star in the area being viewed, building up millions of measurements. The planets detected automatically by SuperWASP were then confirmed using giant telescopes on La Palma in the Canary Islands, Chile and Southern France. The new planets range in size from half to 8.3 times the size of Jupiter. One, named WASP-12B, takes just over a day to orbits its parent star. It lies so close to it that daytime temperatures are thought to reach 2,300 C. Discovery team member Dr Don Pollacco, of Queen's University Belfast, said: "SuperWASP is now a planet-finding production line and will revolutionise the detection of large planets and our understanding of how they were formed. It's a great triumph for European astronomers." Dr Carole Haswell, of the Open University at Milton Keynes, had the idea of using eBay to find the extra lenses from sellers around the world. This week's National Astronomy Meeting is organised by the Royal Astronomical Society. The photo shows one of the SuperWasp cameras. Picture: David Anderson • 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