Hello, astro-nuts!

The lovely clear skies came and went, and now it is back to being cloudy and dreary (and windy!). February is pretty much over now, which means we may start seeing signs of spring at some point soon....just not this weekend! I would say that, at least here in State College, March is coming in like a lion! I have heard from some of you that you'll be posting pictures and video of comet Lulin and other neat sky events; keep me posted about your postings so I can mention them here! There are a couple of interesting stories to talk about today; one discusses the dune fields across Saturn's moon Titan, and another discusses a solar eclipse as seen from the Moon!

Check This Out!

First and foremost, a pretty picture of Comet Lulin, thanks to Jay Edwards! Keep checking the AccuWeather.com Photo Gallery, a few of you have posted and said you will post pics and videos of Lulin on there.

If you are lucky enough to have clear skies tonight, check out the western sky around sunset. The just-after-new Moon and Venus will make a pretty pair as they will only be about one degree apart (for reference, put up your thumb and hold it out at arm's length. Venus and the Moon will fit just about at the tip. Venus will shine brightly at around magnitude -4.6; twenty times brighter than Sirius. If you are using a telescope you'll notice that both Venus and the Moon are in a pretty crescent phase; the Moon at 10% illumination and Venus 20%.

A couple of weeks ago, two satellites high above Earth collided; the remaining pieces are still being tracked and counted. So far, the count for Iridium 33 is 109, and for Kosmos 2251, 245. New computer images are available to show where the majority of the debris from Iridium 33 and Kosmos 2251 are located in orbit among all the other space debris. Both maps reveal that Kosmos debris is scattered more widely than that of Iridium 33. Some of the Kosmos fragments have descended to the same orbit level as the ISS; however, little danger is posed to the station as the fragments are mainly over the Antarctic.

Astronews!

The dune fields across Saturn's largest moon, Titan, have been mapped using four years worth of radar data from Cassini. Some 20 radar images were digitized and combined to produce the new map of the dunes, of which there were about 16,000. The orientation of the dunes has scientists scratching their heads about the global winds there because the dunes run from east to west, while the winds blow from the west to the east. This tells them that the surface winds go opposite the way suggested by previous global circulation models of Titan. The lack of clouds on Titan has made it diifficult to determine global wind direction; however, tracking the formation of the sand dunes has given some better insight. Knowing how the wind pattern on the big moon will be helpful for future endeavors to send craft such as balloons into the atmosphere to study Titan further. The dunes are believed to be made of hydrocarbon sand grains and tend to accumulate near the equator and can pile pretty high. Drier conditions in this area may allow for easier wind transport. Meanwhile, the higher latitudes are thought to be more damp with liquid hydrocarbons, which would be tougher for sand to move around. The Cassini spacecraft is expected to pass by Titan again at the end of March; a total of seventeen flybys are scheduled for 2009.

Japan's Kaguya lunar orbiter has sent back some amazing imagery direct from the Moon; high-resolution images of a solar eclipse were recently captured and made into a movie. The Sun, Earth and Moon lined up nearly in a perfect row on February 9th. From the view of Kaguya, Earth moved right in front of the Sun, causing a "diamond ring" eclipse. When the event first began, Kaguya could not see clearly because of the lunar horizon. However, as the movie progresses, the view improves and you can see Earth moving past the sun, which lights up Earth's atmosphere, resulting in a ring of light. Kaguya is the largest Moon mission since the Apollo program. Kaguya consists of a mother ship and two smaller orbiters which are working together to relay data back to Earth even from the Moon's far side. The HDTV cameras aboard Kaguya were really only meant to provide what are now popular transmissions for Japanese citizens; however, now that this event has been recorded, the cameras may be put to further scientific use. Later in 2009, the US will launch the Lunar Reconnaissance Orbiter, which will then join Kaguya and Chandrayaan-1 in lunar orbit.

The next space shuttle mission has been tentatively rescheduled for March 12th. Work continues to be done on the shuttle's three hydrogen flow control valves, and more testing and study of the valves will be necessary before the Space Shuttle Program Team can give the green light to the Discovery launch. Over 4,000 images of the valves will be taken and inspected closely for cracks or other damage. Engineering teams will analyze and test the valves to determine the consequences if they were to be damaged or break off and strike a pressurization line between the shuttle and external tanks. It may be necessary for hardware to be installed around the lines to protect them. Part of the delays in launch has also been because teams were trying to identify what caused damage to a control valve aboard Endeavour back in November. A readiness meeting will be held on March 4th to go over the new data and assess current work on the valves.

Keep your eyes to the sky and enjoy the view!
~Lisa C.

Posted by Lisa Beightol on Friday, February 27, 2009 7:39 AM
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