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CryoSat Version 2.
The loss of CryoSat was a sad day for Earth observation. It was destroyed in October 2005 when an onboard flight-control system failed on a Russian Rockot launch vehicle. But engineers kept their plans, and the development of CryoSat version 2 is well underway. This replacement spacecraft is scheduled for launch in 2009, and will measure the thickness of land and sea ice to determine how quickly it's melting away.
With this second try, mission planners have added a few new extras. The spacecraft will be carrying a backup for its main payload, the SAR/Interferometric Radar Altimeter (SIRAL). That means it needs a second set of electronics. More expensive, but it'll have complete redundancy now. Some other design shortcomings were fixed, and the software has been improved to make the spacecraft easier to operate.
If all goes well, the spacecraft should be almost completely reassembled by late 2007, in preparation for its 2009 launch.
Original Source: ESA News Release
A Very Long Lasting Gamma Ray Burst
Gamma ray bursts are some of the most energetic events in the Universe. Even more amazing is just how quickly it all unfolds. One moment, everything's quiet. A moment later, there's a tremendous explosion that we can see from billions of light years away. And just seconds later, it's gone again - the afterglow will be around for a few days, but that's it. Astronomers and spacecraft have only a few seconds to a few minutes to find the explosion and study it before it fades away.
But a recent burst started off so bright, and faded so slowly, that Astronomers were able to study it for months. The burst is called GRB 060729, and it was first discovered on July 29, 2006 by NASA's Swift Satellite. Since it lasted so long, Astronomers think the initial explosion might have been receiving continuous amounts of energy from some other source.
One possibility is a magnetar; a neutron star with an ultra-powerful magnetic field. The magnetic field acts as a brake, forcing the star to slow down, and transfers energy into the gamma ray burst explosion. This energy could keep the afterglow going for weeks and months.
Original Source: NASA News Release
Asteroid Sample Return Mission Proposed
A new NASA mission is being proposed to fly out, extract a sample from a nearby asteroid, and return it to Earth. The asteroid is known as 1999 RQ36, and the mission is OSIRIS.
The mission's acronym is a bit of a stretch. It's 'O' for origins, 'SI' for spectral interpretation, 'RI' for resource identification, and 'S' for security (of our planet). Put those all goals together, and you get OSIRIS.
The mission itself, though, sounds really cool. If all goes will, it'll launch in 2011, reach asteroid 1999 RQ36 in 2013 and acquire a sample, and then return it back to Earth by 2017.
1999 RQ36 is a useful target for two reasons: it's close, and it's covered in organic material that will provide scientists with valuable data about how our planet formed billions of years ago, and what conditions were around for the formation of life. OSIRIS will return 150 grams (5 ounces) of the asteroid to scientists here on Earth to study. It's actually a lot cheaper and easier to send a sample return mission than to try and send sample analysis equipment to the asteroid.
OSIRIS was one of two dozen proposals given to NASA as part of its Discovery program. Which mission concepts will finally go ahead will be decided in late 2007.
Original Source: NASA News Release
Seas Discovered on Titan
Planetary scientists had reported lakes around Titan's southern poles, but now it looks like the northern hemisphere has liquid on the surface as well. Of course, we're not talking about water, that would be frozen solid. These are seas filled with liquid methane or ethane.
The seas were turned up by Cassini's radar instrument during a recent flyby past Titan's north pole. The largest of these features measures about 100,000 square kilometres (39,000 square miles). That's a surface area larger than Lake Superior here on Earth.
Since Cassini used its radar instruments to image the seas, scientists aren't completely positive that's what they're looking at. In rader, liquids appear as dark patches, indicating smooth surfaces. Another flyby is planned for May, where Cassini will fly directly over these dark patches and get a better look.
Original Source: NASA/JPL News Release
Photo Contains More Than 1,000 Supermassive Black Holes
Each of the multicoloured dots in this photograph is a black hole. The panorama was created using images taken by NASA's Chandra X-Ray Observatory, the Spitzer Space Telescope, and several ground-based telescopes. The scale image of the Moon should give you an idea of how large a portion of the sky was imaged.
Each one of black holes in the picture is really the supermassive black hole that lies at the heart of another galaxy. Although the singularity itself is black, material chokes up around it, releasing the radiation we see. Astronomers call these active galactic nuclei, or AGNs.
This impressive new survey raises some doubts about what the environment around these black holes looks like. Astronomers used to think they were surrounded by a torus (or doughnut) of gas. This torus would block our view of certain kinds of radiation depending on its orientation. We should see some black holes unobscured, others partially obscured, and some completely obscured.
But instead of matching this prediction, the black holes are either completely visible, or totally obscured, and almost nothing in between. Astronomers will have to revise their models to better understand the environment around an actively feeding black hole.
Original Source: Chandra News Release
Radioactive Core Might Explain Geysers on Enceladus
Since Cassini arrived at Saturn, it has made many impressive discoveries. One of the most intriguing is the discovery that Saturn's icy Moon Enceladus has geysers spewing water ice into space. Some planetary scientists theorize that there are pockets of liquid water near the surface of Enceladus that could harbour life. But where is the heat coming from to fuel these geysers?
A new model proposes that the rapid decay of radioactive elements might be keeping the Moon hotter than it would normally be. This heat is released through cracks in the moon's surface, and since Enceladus is covered with ice, it has water geysers.
The theory says that Enceladus started out as a ball of ice and rock, with rapidly decaying isotopes of aluminum and iron. Over the course of just a few million years, this decay produced a tremendous amount of heat, creating a rocky core and a surrounding shell of ice. The Moon then slowly cooled over the course of billions of more years.
This theory matches some of the elements seen in Enceladus' geysers, such as gaseous nitrogen, methane, carbon dioxide, propane and acetylene. These could come from the decomposition of ammonia deep inside the Moon where the warm core and water meet.
Original Source: NASA/JPL News Release
New Globular Cluster Discovered
Globular star clusters are gigantic collections of stars formed at the same time, and held together by their mutual gravity. Amazingly, they're some of the oldest objects in the universe - some are more than 10 billion years old. More than 150 globular clusters have been discovered in the Milky Way by astronomers. And now you can add one more to that list.
The new cluster is located about 30,000 light years away, in the inner dust-shrouded parts of the Milky Way. Since it's only about 10,000 light years from the centre of the Milky Way, it would normally be hidden to observatories that see in the visible spectrum. The European Southern Observatory's New Technology telescope can see into the Infrared spectrum, revealing objects behind the obscuring dust.
Living inside the cluster would be an amazing experience. It's only 7 light-years across. This is only double the distance from the Sun and its nearest star, Proxima Centauri. Instead of just a couple of stars in this volume, you would see more than 100,000 stars blazing in the night sky.
Original Source: ESO News Release
What's Up this Week: March 12 - March 18, 2007
Monday, March 12 - Tonight let's return again to NGC 2362 and start at the cluster's north-northeast corner to have a look at a single, unusual star - UW Canis Majoris. At magnitude 4.9, this super-giant spectroscopic binary is one of the most massive and luminous in our galaxy. Its two stars are separated by only 27 million kilometers (17 million miles_ and revolve around each other at a frenzied pace - in less than four and a half days. This speed means the stars themselves are flattened and would appear to be almost egg-shaped. The primary itself is shedding material that's being collected by the secondary star.
Now drop southwest of NGC 2362 for another open cluster - NGC 2354. While at best this will appear as a small, hazy patch to binoculars, NGC 2354 is actually a rich galactic cluster containing around 60 metal-poor members. As aperture and magnification increase, the cluster shows two delightful circle-like structures of stars, similar to a figure 8. Be sure to make a note' You've captured another Herschel 400 object!
Tuesday, March 13 - On this day in 1781, Uranus was discovered by William Herschel. Also on this day, in 1855, Percival Lowell was born in Boston. Educated at Harvard, Lowell went on to found the observatory which bears his name in Flagstaff, Arizona, and spent a lifetime studying Mars. This morning, you can honor Lowell by seeing Mars yourself before sunrise. While there won't be a great many details, think of how many strides have been made since Lowell's time and how advanced our knowledge of Mars has become!
Tonight let's hop about four fingerwidths east-northeast of Sirius. Look for 5th magnitude SAO 152641 to guide you to a faint patch of stars in binoculars and a superb cluster in a telescope - NGC 2360. Comprised of around eighty 10th magnitude and fainter stars, this particular cluster will look like a handful of diamond dust scattered on the sky. Discovered by Caroline Herschel in 1783, this intermediate-aged galactic cluster is home to Red Giants and heavy in metal abundance. Mark your notes, because not only is this a Herschel object, but is known as Caldwell 58 as well!
Wednesday, March 14 - Today is the birthday of Albert Einstein. Born in 1879, Einstein was one of the finest minds of our times. He developed the theory of gravity in terms of Spacetime curvature - dependent on the energy density. Winner of the 1921 physics Nobel prize, Einstein's work on the photoelectric effect is the basis of modern light detectors.
Tonight let's hop about a fistwidth north of bright Eta Canis Majoris and have a look at a 'double cluster' - NGC 2383 and NGC 2384. Just showing in binoculars as a faint patch, this pair will begin resolution with larger scopes. Studied photometrically, it would appear these fairly young clusters have contaminated each other by sharing stars - which has also occurred in some clusters located in the Magellanic Clouds. Enjoy this unusual collection of stars'
Thursday, March 15 - Today celebrates the birth of Nicolas Lacaille. Born in 1713, Lacaille's measurements confirmed the Earth's equatorial bulge. He also named fourteen southern constellations. To honor Lacaille tonight, let's begin some explorations in a constellation he named - Puppis!
For SkyWatchers living in high northern latitudes, you'll never see all of this constellation, but there will be some things for you to explore, as well as a great deal for our friends in the southern hemisphere. The first is a Herschel object that lies directly on the galactic equator around five degrees north-northwest of Xi.
NGC 2421 is a magnitude 8.3 open cluster that will look like an exquisitely tiny 'Brocchi's Cluster' in binoculars and begin good resolution of its 50 or so members to an intermediate telescope, in an arrowhead-shaped pattern. It's bright, it's fairly easy to find, and it's a great open cluster to add to your challenge study lists!
Friday, March 16 - On this day in 1926, Robert Goddard launched the first liquid-fuel rocket. But he was first noticed in 1907 when a cloud of smoke issued from a powder rocket fired in the basement of the physics building in Worcester Polytechnic Institute. Needless to say, the school took an interest in the work of this shy student. Thankfully they did not expel him, and thus began his lifetime of work in rocket science. Goddard was also the first to realize the full implications of rocketry for missiles and space flight, and his lifetime of work was dedicated to bringing this vision to realization. While most of what he did went unrecognized for many years, tonight we celebrate the name of Robert H. Goddard. This first flight may have gone only 12 meters, but forty years later on the date of his birth, Gemini 8 was launched, carrying Neil Armstrong and David Scott into orbit!
Tonight we'll pick up a challenge cluster and a planetary nebula on the Herschel list by returning to NGC 2421 and hopping about a fingerwidth northeast for NGC 2432. This small, loose open cluster is rather dim and contains around 20 or so faint members shaped like the letter B. About another degree northeast is NGC 2440 - an elongated, small 11th magnitude planetary nebula. Look for its central star to cause a brightening and up the magnifying power to reveal it.
While out, be on watch for the Corona-Australids meteor shower. While the fall rate is low - 5 to 7 per hour - our friends in the southern hemisphere might stand a chance with this one!
Saturday, March 17 - If you're up before dawn this morning, Mercury will be about 1 degree north of Moon. This could be an occultation from your area, so be sure to check IOTA!
On this day in 1958, the first solar-powered spacecraft was launched. Named Vanguard 1, it was an engineering test satellite. From its orbital position, the data taken from its transmission helped to redefine the true shape of the Earth.
Tonight let's return to Xi Puppis and head less than a fingerwidth east-northeast for Herschel study NGC 2482. At magnitude 7, this small fuzzy spot in binoculars will resolve into around two dozen stars to the telescope. Look for the diagonal chain of stars along its edge.
Now drop about two fingerwidths south of Rho in chains.
Sunday, March 18 - Although you can't see it with just your eyes, Uranus is less than a degree from the Moon this morning. For some areas this could be an occultation, so be sure to check IOTA information!
Today in 1965, the first ever spacewalk was performed by Alexei Leonov onboard the Soviet Voskhod spacecraft. The 'walk' only lasted around 20 minutes and Alexei had problems in re-entering the spacecraft because his space suit had enlarged slightly. Imagine his fear as he had to let air leak out of his space suit in order to squeeze back inside. When they landed off target in the heavily forested Ural Mountains, the crew of two had to spend the night in the woods surrounded by wolves. It took over twenty-four hours before they were located and workers had to chop their way through the forest and recover them on skis. Brave men!
Tonight let's honor them by studying a small area which contains not only three Herschel objects - but two Messiers as well - M46 and M47. You'll find them less than a handspan east of Sirius and about a fistwidth north of Xi Puppis.
The brighter of the two clusters is M47 and at 1600 light-years away, it's a glorious object for binoculars. It is filled with mixed magnitude stars that resolve fully to aperture with the double Struve 1211 near its center. While M47 is in itself a Herschel object, look just slightly north (about a field of view) to pick up another cluster which borders it. At magnitude 6.7, NGC 2423 isn't as grand, but it contains more than two dozen fairly compressed faint stars with a lovely golden binary at its center.
Now return to M47 and hop east to locate M46. While this star cluster will appear to be fainter and more compressed in binoculars, you'll notice one star seems brighter than the rest. Using a telescope, you'll soon discover the reason. 300 million year old M47 contains a Herschel planetary nebula known as NGC 2438 in its northern portion. The cluster contains around 150 resolvable stars and may involve as many as 500. The bright planetary nebula was first noted by Sir William Herschel and then again by John. While it would appear to be a member of the cluster, the planetary nebula is just a little closer to us than the cluster. Be sure to mark your notes' There's a lot there in just a little area!
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