Researchers from NASA have confirmed that it would have been impossible for advanced life forms, like fish or mammals, to live in the Earth's early oceans because it was such a toxic environment. The scientists studied ancient rock formations, and found evidence of photosynthetic bacteria living as recently as 1.6 billion years ago. This bacteria would have required both sunlight and an environment rich in hydrogen sulfide - this environment would have been quite toxic for air breathing creatures.

ESA's CryoSat ice observation satellite is scheduled for a Saturday launch from Russia's Plesetsk Cosmodrome. Once in orbit, the satellite will used a specialized radar altimeter to measure changes in land and sea ice thickness over a three-year period. Until now, scientists have known that Arctic sea ice is shrinking, but not if it's thinning. Existing Earth observation satellites don't have the resolution to detect smaller pieces of pack ice, so CryoSat will help fill the gaps.

This Cassini photograph shows several of the large craters that pockmark Dione, one of Saturn's moons. The most prominent crater in the image is 188 km (73 mile) Dido, and the smaller crater above it is Antenor. On the sunlit side you can see some of the wispy markings, which Cassini has revealed to be a complex system of fractures in the moon's surface.

Gregory Blount captured this image of the International Space Station as it passed over his my farm near Ketchum, Ok. Greg used a Nikon D70. This photo is facing south, just as ISS passed below Corona Borealis and into Sagittarius.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Scientists from the University of Arizona think they have an explanation for a strange bright spot on the surface of Titan. It originally wasn't clear whether this crescent-shaped feature was a mountain, cloud, or even a geological hotspot. By comparing observations of the region in both visible wavelengths and microwave radiometry, the scientists were able to rule out hotspots. It hasn't moved for years, so it's probably not a cloud. They currently think this region must be a bright patch with a different composition to the surrounding areas.

NASA engineers tested out a prototype unmanned sailplane this week at the Dryden Flight Research Center in California. This robotic aircraft is capable of detecting and using rising air thermals, similar to a glider or bird, to gain altitude. It launched from the ground, and navigated to a likely location for updrafts. Once it found a thermal, it turned off its engine and circled to stay within the updraft. NASA hopes to develop techniques for using thermals that could extend the range of unmanned aerial vehicles that often have very limited fuel.

An international team of astronomers think they've solved the mystery of short gamma-ray bursts. These powerful explosions shine brighter than a billion suns for only a few milliseconds and fade away quickly. But now, thanks to NASA's Swift satellite, which can detect and analyze these blasts anywhere in the sky, astronomers were able to measure short bursts. The evidence now points to the theory that these bursts occur when a black hole consumes a neutron star, or two neutron stars collide together.

Tour guides add vibrant, often personal accounts of locales along your travels. They impart much more knowledge than simply standing in front of a building and reading some brief nameplate. By including a relative context, they tie a building to its neighbours and even substantiate its mere existence. Ron Miller and William K. Hartmann in their book The Grand Tour, A Traveler's Guide to the Solar System equally provide this important service for worlds within our solar system. They take the reader along on a detailed tour, and, without assuming prior knowledge, they vividly distinguish and join each of the worlds into a technical and visual journey.

Tom Davis wows us again with this astonishing picture of M45 (aka Pleiades). It was taken using his AP 155 EDF f/7 refractor and STL-11000M CCD camera.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

NASA's Hubble Space Telescope took this beautiful photograph of supernova remnant N132D, located in the Large Magellanic Cloud - a satellite galaxy to our Milky Way. By measuring the wispy cloud, astronomers estimate that the original star probably detonated about 3,000 years ago. A supernova-generated shockwave is traveling through space at a velocity of more than 2,000 kilometers per second (4 million mph), and colliding with surrounding material. This causes the material to heat up to millions of degrees so we can see it from here on Earth.

Astronomers knew something was hiding inside a dark, dusty cloud, but they weren't sure exactly what it was. The Spitzer Space Telescope confirmed a faint infrared object within the cloud. But by focusing the Hawaii-based Submillimeter Array on the object, astronomers learned that the hidden object has a weak outflow of material, which was predicted by star formation theories. This revealed the object to be a young star, perhaps only 10,000 to 100,000 years old with only 25 times the mass of Jupiter.

Australian researchers are using ESA's Envisat Earth Observation Satellite to peer down and help judge the health of the Great Barrier Reef. Envisat's MERIS sensor can detect coral bleaching down to 10 metres below the surface of the water. This bleaching occurs when the symbiotic algae living with the coral are expelled when ocean temperatures rise. Since Envisat images the entire planet every three days, scientists will be able to watch this bleaching process on a weekly basis to see how the reefs are doing.

Greetings, fellow SkyWatchers! We hope that the skies were cooperative for today's annular eclipse. This week we'll explore the "Helix" nebula, begin tracking a new comet, remember our history, visit the lunar surface, watch Mars and be treated to two meteor showers. So open your eyes to the skies, because...

Here's what's up!

Christophe Bogaert captured today's annular eclipse from Beligium. This partial eclipse was taken using an 8" newtonian telescope with a Canon EOS 300D camera. The final photograph is a stack of three 1/640 sec. exposures.

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The newly discovered 10th planet - which the discoverers have dubbed "Xena" - appears to have a moon of its own. Nicknamed "Gabrielle", this moon is 100 times fainter than Xena, and seems to orbit the planet once every couple of weeks. It's estimated to be 1/10th the size of Xena, so approximately 250 km (155 miles) across. The powerful Hubble Space Telescope will be turning its gaze on the pair in November/December, and should reveal even more details.

The Soyuz spacecraft carrying the crew of Expedition 12 and space tourist Greg Olsen docked with the International Space Station on Monday. The visitors were greeted by the crew of Expedition 11, who have been on board the station for nearly 6 months. Olsen will conduct several experiments on the station, and then return with the crew of Expedition 11 in about a week.

Efrain Morales took this recent photograph of Mars. He took 750 individual frames of the planet with his telescope in Puerto Rico, and then merged them on computer to build these composite photographs.

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According to Genesis, 'First there was light.'. According to scientists, this initial light is still about us, shining down from the heavens. Not only does it shine, it's red-shifted, and, depending on its composition, it indicates whether the universe is static, expanding or contracting. All we need do is detect this light to learn about our origin. This is the story in Michael Lemonick's book Echo of the Big Bang. In particular, he tells the tale of the Wilkinson Microwave Anisotropy Probe (WMAP), its place in remote sensing and its role in cosmology. From it, we learn a little more about the first light and we know it is good.

NASA is planning on sending rovers to crawl around the surface of Mars for the foreseeable future, but there's only so much terrain they can explore. Global Aerospace Corporation is proposing a future balloon mission that would float just a few kilometres above the surface of Mars, and explore a much larger territory in tremendous detail. The balloon would trail a wing beneath that would work like a rudder, and allow it to steer itself in the Martian winds.

The massive Keck Observatory at the top of Hawaii's Mauna Kea has learned a new trick: it can block the light from stars to see faint objects near them. This will be an invaluable tool for analyzing young star systems, since planetary disks are often impossible to see next to the dazzling light of a star. This new instrument is called a "nuller", and it's able to reduce the light from a star by a factor of 100 times. Similar technology will be used in future planet hunting missions to see dim planets lurking beside their stars.

Cassini made its first flyby of Saturn's moon Hyperion last week, and took this amazing photograph. The spacecraft got within 500 km (310 miles), and you can clearly see how unusual this spongy-looking moon is. Scientists think that Hyperion is little more than a pile of rubble, loosely held together by its own gravity because much of its mass is just empty space. Hyperion is only 266 kilometers (165 miles) across, has an irregular shape, and spins in a chaotic rotation.

With the "Snowball Earth" hypothesis, scientists have proposed that our planet was once encased under a thick layer of ice and snow. Life could only survive huddled around hot vents deep under water. But now scientists have found fossil evidence of creatures that lived during this period, but were photosynthesizing. This means they needed to live under thin enough ice for sunlight to get through. It's possible that the entire planet wasn't encased in ice, instead there were large patches of thin ice, or even open water near the equator.

The European Southern Observatory's Very Large Telescope took this incredible image of galaxy NGC 1350, which is located 85 million light years away in the Fornax constellation. Astronomers classify it as an Sa(r) type galaxy, which means it's a barred spiral with two central regions. It is 130,000 light years across, so it's a little larger than our own Milky Way.

Here's an amazing picture of the Antares-Rho Ophiuchus region of the Milky Way taken by Thomas Davis from his home observatory.

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A supernova that exploded 41,000 years ago might have led to the extinction of mammoths, according to researchers at Berkeley Lab. They found ancient mammoth bones peppered with iron-rich grains that had been traveling at 10,000 km/second. These grains might have been emitted from a supernova that exploded about 250 light-years away from Earth. It's also possible that debris from the supernova coalesced into comet-like objects; one could have struck the earth about 13,000 years ago.

The latest images released from the Hubble Space Telescope pinpoint an enormous galaxy located almost 13 billion light-years away - at a time when the Universe was only 800 million years old. This galaxy contains 8 times the mass of stars as the Milky Way, and really shouldn't exist according to current astronomical theories. This research demonstrates that mature stars and large galaxies formed much earlier than astronomers had ever expected.

Paul Mayo captured this photograph of NGC 253 from his backyard observatory in Newcastle Australia. Paul used a Canon EOS 300D to take 7 separate images with his 0.3 metre telescope. You can see more of Paul's amazing photos at his website.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

NASA's New Horizons spacecraft has arrived at Florida's Cape Canaveral to be prepared for launch. If all goes well, New Horizons will lift off atop an Atlas V rocket on January 11, 2006, and begin the decade-long journey to Pluto. It's equipped with seven scientific instruments, and will study Pluto and its moon Charon during a relatively brief flyby. The mission may even be extended, giving the spacecraft an opportunity to study additional objects in the region.

ESA engineers have figured out how to extend the life of SMART-1's ion engine, giving the mission more time to orbit the Moon. The mission was originally supposed to end in May 2006, but by conserving fuel and changing the way it engine operates, the engineers have pushed its demise back to July 2006. SMART-1 is completely out of fuel now, though, and will coast until its decaying orbit smashes it into the Moon.

Greetings, fellow SkyWatchers! Ah, yes. Dark skies are ours again and we'll begin the week with the magnificent M2. There will be plenty of galactic action as we study NGC 7331, hunt down Stephan's Quintet, and relax in the stellar swarm of M34. For early risers, the sky offers some splendid scenery as two planets join two visible open clusters. But dark skies always mean just a little more, don't they? Then think Caldwell 44 and 43 as you open your eyes to the skies, because...

Because here's what's up!

Shahriar Davoodian took this cool picture of the Dumbell Nebula (M27) from Damavand, Iran. He used a Canon EOS 300D attached to a Meade LX90 8" Telescope with a 4 minute exposure.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

That which was old is new again. The Moon, once thought a 'fait accompli', is now firmly back in the centre of many people's targets. We have to thank George W. Bush in giving his recent directive to NASA. This, together with NASA's announcement on how they plan to return to the moon, seems to indicate a golden lunar age has returned. You'd think smiles would be positively radiant at the recent seventh meeting of the International Lunar Exploration and Utilization Working Group, held from September 18-23 in Toronto, Ontario. Yes, many smiles enlivened the group. However, these smiles weren't like that of the child holding a cookie but like those of wise parents checking the list of ingredients. For this cookie has come before but disappeared all too quickly.

Instead of waiting for asteroids to slam into the Earth, the European Space Agency is working on a mission that will reach out and try to shift a space rock's orbit. The mission is called Don Quijote, and it will consist of two spacecraft: an orbiter and an impactor; similar to NASA's Deep Impact. The Sancho orbiter will rendezvous with a target asteroid and carefully calculate its orbit before and after the Hidalgo impactor slams into it. The ESA has chosen two candidate asteroids as potential targets, and will make a final decision in 2007.

A Boeing Delta II rocket successfully launched the first of a new class of modernized Block IIR global positioning system satellites early Monday morning. The rocked lifted off from Space Launch Complex 17A at 0337 GMT (11:37 pm EDT Sunday) from the Cape Canaveral Air Force Station in Florida. This new class of GPS satellites will broadcast additional signals to improve civilian and military accuracy, and prevent any jamming attempts.

Researchers answer their true calling by flinging themself headlong into discovering and perhaps add a little more to humanity's collective knowledge. Their friends, sleep and even food get deleted to a secondary role as just one more lead, one more calculation or one more experiment could endow understanding. The cost for a researcher in answering this call might be years of personal neglect, even though society benefits greatly. Marcelo Gleiser in his book The Dancing Universe takes us through the history of physics from the gods of yesteryear to the cosmologists of today. He focuses on some of the really productive researchers and, in so doing, gives us a clearer understanding of physics, people and our society.

Joe Cahak captured this beautiful photograph of light from the setting Sun glinting off the launch trail left by yesterday's Minotaur rocket from Vandenberg Air Force Base.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

The European Space Agency's Envisat satellite took this photo of Hurricane Rita on September 22, 2005 as it was passing Southern Florida. Envisat can use its radar instruments to peer through a hurricane's clouds and measure the roughness of the ocean beneath it. This is how scientists can estimate the wind speed of the storm at various points. Rita is expected to slam into Texas or Louisiana early Saturday morning.

By looking at the most distant Universe, astronomers are hoping to learn what kinds of galaxies formed first, leading through mergers to the mature galaxies we see today. The more galaxies you look at, the better the predictions. A team of French and Italian astronomers have used the VIsible Multi-Object Spectrograph (VIMOS) instrument on one of the ESO's 8.2 m telescopes to image and measure thousands of galaxies. They found 2 to 6 times as many early galaxies with vigorous star formation than astronomers had previously expected.

In 1572, Danish astronomer Tycho Brahe observed and studied an exploding star that would later be named after him. NASA's Chandra X-Ray Observatory shows that the Tycho's Supernova remnant is an expanding bubble of debris which is inside a larger bubble of high-energy electrons. Astronomers think that remnants like this could be a source of cosmic rays; high-energy nuclei found throughout the galaxy which constantly bombard the Earth.

To have the current elements in the Universe, cosmologists believe there had to be several generations of stars, building up heavier and heavier elements. But what did that first generation of stars look like? They were probably huge, weighing 50-500 times the mass of the Sun. They lived quickly and then died as massive supernovae that seeded the surrounding space with heavier elements forged during this explosion. They could even be the source of gamma ray bursts, which are the most powerful known explosions in the Universe.

The European Space Agency's Mars Express spacecraft will have its mission extended by one Martian year - approximately 23 months - beginning December 2005. Since it began science operations in early 2004, Mars Express has made several findings: volcanic and glacial processes happened quite recently; there are small quantities of methane gas in the Martian atmosphere, which could indicate life; and large bodies of liquid water might have lasted under the surface of Mars for a long period of time.

Cassini recently took this beautiful photograph of Saturn's rings, sweeping across the sky. Its tiny moon Pan (26 kilometers, or 16 miles across) is barely visible inside the Encke gap, in the middle of the photograph. The Cassini Division is the darker area at the upper left-hand portion of the picture.

Beauty is in the eye of the beholder. For a desolation to be beautiful, there must be something special. Just after Dr. Buzz Aldrin stepped onto the moon, Neil Armstrong asked him what were his thoughts. He replied, "it's a magnificent desolation". Nearly forty years later, Tom Hanks, Gary Goetzman and Mark Cowen combine the wizardry of IMAX with the magic of top flight professional entertainers to the film Magnificent Desolation. The result puts the viewer on the surface of the moon and lets them experience its strange but magnificent beauty all for themselves.

NASA has announced its fifth Centennial Challenges prize competition: the Regolith Excavation Challenge. Teams will compete head to head in 2006 or 2007 to see whose digging machine can excavate the most lunar soil, or regolith, in 30 minutes and deliver it to a collector. Any future moon base will require large quantities of regolith to be moved around by robotic diggers, so NASA is hoping to see innovative ideas now to base future technologies around.

Mars is a more dramatically changing place than scientists had ever imagined. Thanks to its long lifetime, the Mars Global Surveyor has spotted a gully coming down the side of a sand dune that didn't exist just three years ago. The gully could have formed when frozen carbon dioxide was suddenly warmed up enough that it evaporated, releasing gas that flowed downhill like a liquid. Mars Global Surveyor is still very healthy, and could be making observations 5-10 years from now.

Newborn stars hide in a shroud of dust and gas, so they're difficult to photograph. Astronomers have used the infrared UKIRT telescope on Mauna Kea, Hawaii to peer through one of these envelopes to see a pair of newborn stars - probably only 100,000 years old. The stars are quite large; however, they weigh 10 times the mass of the Sun together. The surrounding disk of material probably has enough left over to create 100 Jupiter-mass planets.

Astronomers have known about a strange blue light coming from the heart of the Andromeda Galaxy (M31) for many years, but they were never sure exactly what it was. Thanks to new observations from Hubble, they now know it's a ring of young hot stars which are whipping around the supermassive black hole in the middle of M31. The 400 stars are packed into a disk only 1 light-year across, which is nestled inside a larger ring of older, redder stars. Our own Milky Way might have a similar phenomenon, which means this could be the situation in most galaxies.

Of all the meteorites found around the world, on 45 formed before our Solar System. They provide a unique insight into the composition of the stellar nebula that went on to form our Sun and planets. These early rocks have very few volatile materials in them, like zinc, lead and sodium. So this "volatile depletion" must have been one of the first things to happen in the stellar nebula, and not during planetary formation as previously believed.

Astronomers from Case Western Reserve University have created the deepest, wide-view image of the Virgo Cluster of galaxies, which shows the faint web of starlight that connects the different galaxies together. The image was built up over the course of 14 moonless nights using the newly refurbished 24-inch Burrell Schmidt telescope at the Kitt Peak National Observatory in Arizona. This web of stars is evidence of the violent collisions that galaxies go through as they merge together to form larger galaxies.

Researchers from Open University have uncovered that the Earth suffered a sudden, severe period of global warming approximately 180 million years ago. During this period, vast quantities of methane gas were released in three huge pulses when underwater stores of gas hydrate melted. This greenhouse gas warmed the Earth by 10 degrees C and resulted in the extinction of many species on land and in the oceans.