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Explanation of Nebulae.
In case you missed it, I hosted the 4th Carnival of Space yesterday here at universe Today, so no astrosphere. But today is a new day, and there's an astrosphere:
First, Skymania News takes us on a tour of the new planetarium which is part of the restoration of the Royal Observatory in London.
Really Rocket Science considers the Planetary Society's challenge of tagging an asteroid. How hard would it really be?
Space Prizes has a quick note about some new scholarships announced by the American Astronomical Society. $10,000 would go a long way to paying off tuition fees.
Alan Boyle joins other space bloggers in Houston for the International Space Development Conference.
A telescope made from rotating liquid is an old idea, but now people want to put one on the Moon.
The Astroprof gives you a detailed explanation of nebulae.
Coastal Scene on Titan
Take a look at the image attached to this story. If you didn't know any better, you'd think you were looking at a rugged coastline somewhere on Earth. Maybe some island in the Mediterranean, or Norwegian fjord. Nope, you're looking at a completely alien world: Titan.
NASA's Cassini spacecraft took this image on May 12, 2007 during its most recent flyby of Saturn's largest moon. During the flyby, its radar instrument captured this image using its radar instrument. Smooth surfaces, like liquid are seen as black, while the textured regions are land.
While other bodies of liquid such as lakes have been seen on Titan before, nothing has had these kinds of features: channels, islands, bays, and other terrain you'd see on Earth. But instead of water, this liquid is probably a mixture of ethane and methane. Since there are no brighter regions in the liquid regions of the image, scientists are assuming the ocean exceeds tens of metres deep.
The image is about 160 kilometers (100 miles) by 270 kilometers (170 miles) across.
Original Source: NASA/JPL/SSI/ESA News Release
Telescope Under the Ice in Antarctica
If you think you need to install a telescope on a mountaintop, or even above the surface of the Earth, think again. A new telescope currently being installed near the South Pole has detectors more than 2 kilometres under the surface of the Antarctic ice cap. For the neutrinos it's searching for, that much ice is the same as nothing at all.
Neutrinos are illusive particles generated by the fusion reactions in the Sun and other cosmic events. They barely interact with normally matter, passing right through like it's complete vacuum. Only in the rarest occasions will a neutrino collide directly normal matter, releasing a torrent of subparticles and radiation.
Once completed, the IceCube observatory will consist of detectors arranged in a 1 kilometre cubic array frozen underneath the surface of the Antarctic ice cap. Construction is currently into its 3rd year, with more than 20 institutions participating. The final instrument will consist of more than 70 strings, each containing more than 60 optical detectors frozen into the ice.
When operational, IceCube will be able to detect neutrinos from the Sun, as well as some of the most catastrophic events in the universe, such as a supernova or black hole. The neutrinos will interact with particles of ice within the array, and produce a cascade of particles that will produce a flash of light captured by the optical detectors.
The full construction is going to take another 3-4 years, but the array is already operational, and gathering scientific results.
Original Source: University of Delaware News Release
Metal Poor Star Found With Planets
When you look at the ground beneath your feet, you're looking at matter created in the heart of stars at the end of their lives. Some of the heavier elements were fashioned in the supernovae explosions of massive stars. And in many cases, these elements went through several generations of stars. So it was a tremendous surprise this week when Astronomers discovered planets orbiting a metal poor star.
The Discovery was made by a team of researchers from the University of Texas using the 9.2-metre Hobby-Eberly Telescope at McDonald Observatory. They found a system of two Jupiter-like planets orbiting a star that's so low in metals that it shouldn't have planets at all.
But there they are.
The star is known as HD 155358, and the planets were discovered using the radial velocity method, where the gravity from the planets pull the star back and forth with a velocity we can detect here on Earth. This allows Astronomers to calculate their mass and the length of their orbit.
One planet has an orbital period of 195 days and has 90% the mass of Jupiter. The other takes 530 days and has 50% the mass of Jupiter. They actually orbit so close to one another, that they must gravitationally interact. They push each other around.
A commonly-held model of planetary formation requires that there are large quantities of heavy metals present in the protoplanetary disk. Finding such a low metal star, but still with two planets around it, is an impressive find, and will give Astronomers reason to reconsider their theories.
Original Source: UT Austin News Release
Carnival of Space #4
Universe Today is hosting the Carnival of Space for a second week. This time, it's the mighty carnival #4. Once again, we've got a round-up of cool space-related articles from writers and bloggers. If you want to get involved, and maybe even host the carnival in a future week, you can find out more at the Carnival of Space website. Thanks for dropping by, I hope you enjoy the stories.
First up, Chris Lintott takes us into the submillimetre spectrum. And it's looking good.
At Cumbrian Sky, Stuart Atkinson is dreads the day when one of the Mars rovers dies. Not tonight...
The astronomy Picture of the Day submits a dark night over Death Valley, and highlights the dangers of encroaching light pollution.
Deborah Byrd from the EarthSky Blogs is wondering is the line between science and science fiction is beginning to blur with the search for Spock's homeworld.
From hi-tech to low-tech. Do modern assumptions about astronomical observation work when looking at astronomy in ancient societies? Alun Salt from Clioaudio ponders that question.
Alan Boyle from MSNBC's Cosmic Log reports that James “Scotty” Doohan's ashes have been found.
Centauri Dreams considers our future, when the Milky Way and Andromeda Galaxy crash into one another. Who keeps the Sun?
Amanda Bauer is a fan of robots for space exploration, especially those hardworking Mars rovers. But is it time to enact the three laws of robotics?
A Babe in the universe blog reports on the new dedication for the SOFIA airborne observatory.
Getting to space isn't easy. Staying fit in space is hard too. Read this post from James Watt.
Pamela Gay explains the wonders of jets. No, not airplanes; the torrents of particles blasting away from black holes, new stars, and now, a brown dwarf.
Robert Pearlman at collectSPACE has been following the launch of the Shuttle Launch Experience, a new $60 million simulator designed to deliver to tourists at the Kennedy Space Center Visitor Complex the feelings and emotions during a ride to orbit. collectSPACE will be covering the public opening on Friday, but before then, they got an early look inside.
Ian Musgrave from Astroblog has news on an exotic Neptune-sized world covered in hot ice.
Terraforming Mars. Is that a good idea, or a bad idea? Colony Worlds weighs in with an opinion.
When he's not furious, the Angry Astronomer calmly explains stellar evolution in a four part series.
Would you rather see a hundred thousand acres of restored prairie or the same space covered by solar collection arrays? Thought so. But only 62 miles away is nearly limitless room and sunshine undiluted by an inconvenient atmosphere. Brian Dunbar has his opinion.
And finally, I look forward 3 trillion years into our lonely future.
Thanks to everyone who participated, and thanks for letting me be the host. I had a blast. I'll see you next week at the next stop in the Carnival of Space.
Ejected Black holes May Take Their Fuel With Them
The huge majestic spiral Galaxy we live in today was built up over billions of years through mergers with other galaxies. And in 5-10 billion years from now, we'll merge together with the Andromeda Galaxy. Since both galaxies are thought to have a supermassive black hole at their centre, what will happen when they merge together? One possibility is that one black hole will get ejected from the combining galactic core at a tremendous velocity.
Astronomers have suspected this kind of interaction might happen. The velocities and gravitational forces are so great during a black hole merger, that one of the objects could be flung out like a slingshot. It was believed that the black hole would be stripped of its accretion disk as it's flung out into the galaxy, so it would be impossible to detect.
But new calculations by Avi Loeb, a researcher with the Harvard-Smithsonian Center for Astrophysics, indicate that an ejected black hole might be able to bring its accretion disk along for the ride. And the radiation pouring out of this disk might be detectable here on Earth.
If the calculations are correct, the two merging black holes will be releasing torrents of gravitational radiation in the direction they're orbiting. The momentum from this radiation will give one black hole a kick in the opposite direction, ejecting it at 16 million km/hour (10 million mph). At this speed, a black hole would traverse its Galaxy in just 10 million years.
According to Loeb, as long as the gas within the disk was orbiting at a speed far great than the black hole ejection speed, it would follow the black hole on its journey. It could last a few million years, consuming this disk of material, and blazing brightly enough that powerful telescopes could detect it. The host Galaxy would seem to have a double quasar.
Original Source: CfA News Release
Longer Lasting Gamma Ray Bursts
When a gamma ray burst detonates, it releases more energy in just a few minutes than our Sun does in its entire lifetime. For a brief time, a gamma ray burst outshines its entire host galaxy. And now NASA's Swift satellite has found evidence that some bursts can remain active for minutes, or even hours.
Gamma ray bursts are now believed to be a special kind of supernova, where the core of a massive star collapses into a black hole or Neutron star. Inrushing gas forms a disk around the central core, and magnetic fields channel material into twin jets emanating from the black hole at nearly light speed.
Early observations by NASA's Swift satellite found that gamma ray bursts are often followed minutes or hours later by short-lived X-ray flares. These flares suggested that the object that created the gamma ray burst is still active, after that initial flash. Instead of consuming all the material in a single burst of energy, there seem to be ongoing waves of material falling into the black hole. With each wave of consumption, the black hole gives off a torrent of X-ray radiation until everything is gone.
Original Source: NASA News Release
Saturn's rings Could Be Twice as Massive as Previously Believed
New observations from NASA's Cassini spacecraft have revealed that Saturn's largest ring isn't a smooth distribution of particles like it looks in photographs. Instead, it's actually made up of tightly packed clumps of material surrounded by empty spaces.
According to researchers, these clumps of material are constantly colliding, breaking up, and reforming. And these clumps have hidden the mass of Saturn's rings. Scientists originally estimated the mass of Saturn's rings, assuming that particles were evenly distributed. But taking these clumps into account, the rings could be two or more times previous estimates.
To make the calculation, Astronomers measured the brightness of a stars as they passed behind the rings. This allowed Cassini to measure the amount of material obscuring the stars, and so scientists could determine the thickness of the rings. Instead of fading gradually, the stars flickered in brightness as they passed behind these clumps.
These observations confirm that theory that the particles in Saturn's rings gravitationally attract one another, bunching up into “self-gravity wakes”. If they were further from Saturn, the clumps would eventually form moons. But Saturn's gravity tears them apart, halting their growth when they get larger than 30 to 50 meters (about 100 to 160 feet) across.
Original source: NASA/JPL/University of Colorado News Release
Brown Dwarf Discovered with Jets
Jets of material have been seen blasting out of quasars, young stars, black holes and other massive objects. But now Astronomers have discovered that even a lowly brown dwarf can have jets of outflowing material.
The Discovery was made using the European Southern Observatory's Very Large Telescope, which observed the brown dwarf 2MASS1207-3932. It was already a very interesting object because it has a 5 Jupiter mass planetary companion, and it's surrounded by a planetary disc, like a young star. And like many young stars, it's spewing jets of material from its poles.
The brown dwarf only has about 24 times the mass of Jupiter, so it's not large enough to ignite solar fusion. But even so, it has these twin jets of outflow, stretching out a billion kilometres into space.
With an object this small having jets, Astronomers think that young giant planets could also have outflows.
Original Source: ESO News Release
Astrosphere for May 23, 2007
Once again, it's time to see what's happening on other space-related blogs.
Ever wonder what goes into making up a meal for astronauts? Here's a link to a cool video called “Food in Space“.
I know you enjoy Astronomy Cast, but did you know there are dozens of space-related podcasts now? There's a great tool called the Astronomy Media Player, which lists them all, and lets you play recent episodes.
Colony Worlds has an interesting analysis of Ceres as a future target for human exploration.
Want to find your planets? Softpedia has an article pointing the way to finding 4 of them with the unaided eye this week.
Centauri Dreams discusses an interesting way to sail through space, propelled by a magnetic field.
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