Although the Earth’s ozone layer is on the mend, the recovery is going more slowly than expected. Scientists have developed a new computer model that takes existing atmospheric data and correctly reproduces the size and shape of the ozone hole above Antarctica for the past 27 years. The model then predicts into the future, forecasting that the ozone hole will stick around until 2068, and not 2050 as scientists originally believed.
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The Mysteries of Enceladus
NASA’s Cassini spacecraft has been on the hunt for atomic oxygen since it arrived at Saturn. The source turned out to be a thin atmosphere of water vapour surrounding Saturn’s moon Enceladus. Cassini flew past the mysterious moon in July 2005, skimming within 175 kilometres (109) of the surface. It discovered that large dark cracks around its southern pole were warm and spewing out water vapour and ice particles. Cassini is due for a second look in 2008 when it will make another close flyby.
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Hubble Camera is Back Online
NASA officials announced this morning that they were successfully able to restart the Advanced Camera for Surveys on the Hubble Space Telescope. The camera initially failed on June 19 because of power problems. Engineers devised a solution to switch the camera and two other instruments to a backup power system, and began uploading commands on Thursday. The space telescope will resume normal operations on Sunday night.
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Squadrons of Planet Hunters Could Find Life
The Hubble Space Telescope demonstrated that the best viewing is outside the Earth’s atmosphere. Over the years, a series of new telescopes have been lofted into space, and expanded this view into other wavelengths: Spitzer, Chandra, Compton, etc. Next up is the James Webb Space Telescope, with a mirror 6 times larger than Hubble, due for launch in 2013. But these observatories will pale in comparison when squadrons of space telescopes reach orbit. Both NASA and ESA are working on next generation space-based interferometers. They could answer one of the most fundamental questions of science: is there other life in the Universe?
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Desert Varnish Might Be a Clue for Life on Mars
Rocks in the desert can form a shiny coating known to geologists as desert varnish. This varnish forms over thousands of years, and can maintain a record of the life around it by binding DNA, amino acids, and other organic compounds into a silica glaze. Geologists from Imperial College in London think that future rovers should be equipped with instruments that can analyze Martian rocks for the presence of past life in this desert varnish.
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Ring of Light Around Titan
Titan glows with a ring of sunlight in this photograph. The picture was taken by NASA’s Cassini spacecraft when Titan was lit almost completely from behind, and it shows how the light scatters through its thick atmosphere. Cassini took this photo on June 2, 2006 when it was approximately 2.3 million kilometers (1.5 million miles) from Titan.
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Star Forming Regions in Andromeda
Astronomers think that stars form inside collapsing clouds of cold hydrogen gas. This gas is mainly molecular hydrogen; where two hydrogen molecules are bonded together. These clouds are very difficult to see because the Earth’s atmosphere absorbs much of the light that it radiates; however, another gas, carbon monoxide is always present as well, and can be observed easily from Earth. Astronomers from the Max Planck Institute for Radio Astronomy have developed a detailed map of these star forming regions in the Andromeda galaxy.
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Protoplanetary Disk Warped by a Hidden Companion
New images of a relatively nearby protoplanetary disk, taken by the Subaru telescope on Mauna Kea, show strange banana-shaped arcs surrounding the central core. The most likely explanation for these arcs is that there’s another object orbiting the star; either a companion star or a large planet, and the gravitational interaction of this companion is distorting the disk of material. The protoplanetary disk, known as HT142527, is located 650 light-years away from Earth.
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Cassini’s Mission is Half Over
NASA’s Cassini spacecraft will reach the half-way point of its 4 year mission on Friday – it arrived at Saturn on June 20, 2004. Although the spacecraft has already visited Titan 15 times, it’ll pick up the pace for the remainder of its mission, performing another 30 flybys. Starting in July, mission controllers will begin altering Cassini’s orbit with respect to the Sun by nearly 180-degrees. This will give it a bird’s eye view of Saturn’s ring system.
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Interacting Galaxies Generate a Supernova
When galaxies interact, it’s never a pretty picture. But it can be a source of rebirth and renewal. In this photograph, captured by the European Southern Observatory’s Very Large Telescope, galaxy NGC 5917 (at the top) is tearing apart its nearby neighbour. The tidal forces between galaxies cause huge clouds of gas and dust to compact, creating nurseries of giant, hot stars. These stars live fast and die young as powerful supernovae. Supernova SN2005cf was discovered last year along the bridge connecting the two galaxies.
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