Universe Today

Hubble, Chandra, and Spitzer – NASA's three Great Observatories – teamed up to create this beautiful photograph of supernova remnant N49. Under visible light, this is the brightest remnant in the Large Magellanic Cloud. It has a strange lopsided shape; unusual because most supernova remnants are spherical. The new data from the triplet of telescopes have revealed that the strange shape is happening because the remnant is expanding into a region of denser gas on one side.
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Type 1a supernovae are used to measure distance in the Universe because they explode with the same brightness, detonating when a white dwarf star consumes a specific amount of material from a binary companion. The accuracy of these distance measurements depends on the shape of the blast. New research indicates that Type 1a supernovae explosions start out clumpy and uneven, but a second, spherical blast overwhelms the first creating a smooth residue. This sets the limits of uncertainty on distance measurements that use Type 1a supernovae.
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NASA senior managers have picked December 7 for the next launch for the space shuttle Discovery. If all goes well, STS-116 will blast off at 9:35 pm local time (0235 GMT December carrying 7 astronauts, and return to the International Space Station. This time, the construction job will be to install a new section of the station's girder-like truss, and activate its power and cooling systems.
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If you want to get a good view of something, you'll want a big telescope, or you want to get close. NASA has decided to both, equipping its new Mars Reconnaissance Orbiter with the largest spacecraft telescope ever built, and then flying it closer to Mars than any previous spacecraft. This telescope is called the High Resolution Imaging Science Experiment, and returning the most detailed images ever seen of the Martian surface. Dr. Alfred McEwen from the University of Arizona is the Principal Investigator on the HiRise instrument, and he joins me from Tuscon Arizona.
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Once again, I've got a little giveaway for the alert Universe Today reader. This time we're giving away a copy of the Year in Space 2007 desk calendar, which will be be sponsoring Universe Today until the end of the year. All you have to do to enter is send me an email with the subject line, "Year in Space 2007 Giveaway", before Saturday, December 2nd at 12:00 noon (Pacific Time). I'll choose one lucky winner at random from the entrants. Then I'll throw away all the other emails (for your privacy).
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Oxygen makes up 21% of the Earth's atmosphere, and we need it to breathe. But early organisms would have found this environment toxic. Ancient bacteria evolved protective enzymes that prevented oxygen from damaging their DNA, but what evolutionary incentive did they have to do this? Researchers have discovered that ultraviolet light hitting the surface of glacial ice can release molecular oxygen. Bacteria colonies living near this ice would have needed to evolve this protective defense. They were then well equipped to handle the growth of atmospheric oxygen produced by other bacteria that would normally be toxic.
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NASA's newest visitor to the Red Planet, the Mars Reconnaissance Orbiter, has been taking a torrent of photographs at the highest resolution ever captured. The spacecraft's High Resolution Science Imaging Experiment (HiRISE) has taken almost 100 images since its main science mission began on November 7. The image with this story shows sculptured sand dunes inside Russell Crater on Mars, but an 15 additional images are featured on the HiRISE website.
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Get ready Mars, you're about to have a visitor. ESA's Rosetta spacecraft, officially headed towards its 2014 encounter with comet 67P Churyumov-Gerasimenko, will pass by Mars in February 2007. This close encounter will give scientists an opportunity to test out Rosetta's optics and scientific instruments on a well photographed target. Rosetta will also get a gravity assisted speed boost as it swings by the planet. Its closest approach will occur on February 25, when its passes just 250 km above the Martian surface.
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Astronomers don't know what dark matter is, but they do know it takes up approximately 25% of the Universe. We can't see it, but we can measure the effect of its gravity on stars and galaxies. A powerful detector, deep underground in a mineshaft in Minnesota might be able to get to the bottom of the mystery. The Cryogenic Dark Matter Search II project will attempt to detect Weakly Interacting Massive Particles (aka WIMPS). These theoretical particles don't normally interact with matter, but the occasional rare collision might be detectable.
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Most scientists agree that a large asteroid strike 65 million years ago ended the dinosaurs' reign on Earth. Some think that a single strike did the trick, while others think it was multiple strikes and additional stresses that pushed the dinosaurs into extinction. New evidence from researchers at the University of Missouri-Columbia supports the single impact hypothesis. They found a single layer of impact-related material in the geologic record that exactly matched marine creatures known to be contemporaries of the dinosaurs. They didn't find any other impact evidence above or below this layer, reducing the possibility of additional impacts.
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Most parents have had that uncomfortable conversation with their children at some point. Mommy, Daddy, where do stars come from? You hem and haw, mumble a few words about angular momentum and primordial hydrogen and then cleverly change the subject. Well, you don't have to avoid the subject any longer. Pamela and Fraser describe formation of stars, large and small, in a tasteful manner, using only understandable and scientific language.
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Astronomers have discovered a gamma ray source in the sky that acts like a natural clock. The object is called LS 5039, and consists of a massive blue star orbiting an unknown object – possibly a black hole. The two objects orbit each other closely, completing an orbit every four days. With each orbit, the black hole flies through the blue star's stellar wind, and accelerates particles to gamma ray levels. This is the first time a source of gamma rays has been discovered with such a regular schedule.
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Saturn's tiny moon Daphnis makes waves as it orbits the Ringed Planet. Even though it's only 7 km (4.3 miles) across, the moon's gravity draws material along the edges of the Keeler gap, creating the serrated knife edge you see in this picture. Cassini took this photo on Ocrober 27, 2006 when it was approximately 325,000 kilometers (202,000 miles) from Daphnis.
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Take a look at this photograph. See Pluto? It's that little orange speck. This photograph was taken by the Pluto-bound New Horizons spacecraft. Although Pluto is just a tiny dot today, it's going to get a lot bigger over the next 10 years when the spacecraft makes its close encounter in 2015. New Horizons used its Long Range Reconnaissance Imager (LORRI) to capture images of Pluto's region of space over several days. Scientists then analyzed the images, looking for an object moving at the right speed across several frames.
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ESA's Integral space observatory has spotted a blast of gamma rays from a suspected black hole in the Milky Way. the outburst occurred on September 17, 2006, and gradually built in brightness over the course of a few days before declining again. It's this rise and fall of brightness, called a light curve, that allowed astronomers identify the source as a black hole. It's likely that a disk of gas and material orbiting the black hole became unstable, and a portion of it collapsed, creating the outburst.
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