Hello, astro-nuts!
For those of you celebrating the holiday on Thursday, I hope you have a wonderful day; travel safely, eat well, and if you get the chance at night, go outside and look up. Anyway, the Endeavour astronauts have completed the fourth and final spacewalk of STS-126, and the mission has been extended for an extra day. Meanwhile, Hubble has made another pretty picture in the constellation Carina, and we will revisit that weird green cloud known as Hanny's Voorweep.
Check This Out!
I'm sure by now many of you have heard about the NASA toolbag that has been circling Earth since it floated away from Endeavour astronauts on the second space walk last week. So far there have been reports of people being able to see it through binoculars, with an estimated magnitude of about +6.4. Today is unfortunately the last day to see it around here, but spaceweather.com allows you to enter your location so you can see if you can try to spot it over the next few days.
I'm hoping for some decent weather around here this weekend; I don't know about you but I'm really anxious to see the event that will take place November 29-December 2 with Venus, Jupiter and a thin crescent moon! Keep your eyes turned to the south-southwest at sunset. Jupiter and Venus will be within two degrees of each other; the Moon will be below and right of Venus near Sagittarius on 29th before moving closer to the planetary pair on the 30th and December 2nd. Elvis fans! The King has his own asteroid, and it will make its closest approach to Earth today at a distance of 119,262,300 miles. Asteroid 17059 Elvis was discovered in 1999. Meanwhile, Asteroid 2008 WC will pass within 1,208,425 miles of Earth tomorrow.
The Sun continues its jaunt through the zodiac and is now making a very short pass through the constellation Scorpius. When I say short I mean seven days; November 23-29, and will then move into the lesser-known 13th zodiacal constellation, Ophiuchus, on the 30th. Scorpius is of course a scorpion; the mythology behind the constellation says that Scorpius was the killer of Orion the Hunter. The scorpion was sent to punish Orion, who had started thinking a little too highly of himself, and never considered the small creature much of a threat; then he was stung. Orion's last wish was to never be in the sky at the same time as the scorpion, so he rules the winter sky while Scorpius occupies the summer sky. Scorpius is loaded with deep-sky goodies like globular cluster M4 and open clusters M6 and M7. Ophiuchus, the Serpent Holder, is considered the only constellation to be patterned after a human historic figure. Its history takes us back all the way to 27th century B.C. to Imhotep. 2500 years later he was still revered as an incredible leader as well as a god who had amazing powers of medicine and healing. In mythology, Ophiuchus was named for the Greek God of medicine, Aesclepius, who was struck and killed by a thunderbolt when trying to bring Orion back to life. There are, of course, other stories behind Ophiuchus. The constellation contains several Messier Objects such as dense cluster M19, the famous Barnard's Star, and the Pipe Dark Nebula.
Astronews!
The final spacewalk of the STS-126 mission was completed on Monday; astronauts completed all tasks that were given to them, which included some renovating of the International Space Station. Astronauts Steve Bowen and Shane Kimbrough ended their six hour, seven minute spacewalk around 7:30pm EST Monday evening. The spacewalk work included cleaning and replacing eleven ball bearings of a rotation device that was part of a double solar antenna array. A camera was also installed on one of the truss segments and an GPS was placed on the Japanese Kibo Laboratory. Since the ISS has been in orbit, there have been 118 "extra vehicular activities"/spacewalks, with 745 hours and 29 minutes having been used to build or repair the ISS. The mission was extended to Sunday so that a centrifuge motor inside the ISS distillation unit could be repaired. The shuttle Endeavour will undock from the ISS Friday morning and return to Kennedy Space Center on Sunday around 1:18pm.
Quite awhile ago, I talked about Hanny's Voorweep, a bizarre green cloud located about 60,000 light years from galaxy IC2497. There had been questions about its origin and composition, and why there were no stars within the cloud. Thanks to new observations from radio telescopes, some new information has been found. The gas within the strange cloud is very hot; not only that, but a jet of energized particles is being generated by the black hole at the center of IC2497 and is creating a clear path right to Hanny's Voorweep. This channel allows strong optical and UV emissions to light up a part of the gas cloud that surrounds the galaxy. These emissions also heat and ionize the gas cloud, which creates Hanny's Voorweep. A remaining question is where the large amounts of hydrogen gas are coming from; the gas cloud has a mass 5000 times that of the Sun! The thinking is that perhaps the gas came about from an interaction between IC2497 and another galaxy several hundred million years ago. The stream of gas ends about 300,000 light years westwards of IC2497, so perhaps a group of galaxies at the tip of the stream had something to do with the Voorweep's creation.
Hubble does it again! Two of the most massive stars in our galaxy have recently been photographed by the Hubble Space Telescope. The pair had, until recently, been rather difficult to study. The huge stars WR 25 and Tr16-244 are located in the open cluster Trumpler 16, which is located in the Carina Nebula, which is within the southern constellation Carina the Keel. Got all that? The Carina Nebula is known for containing hot stars and two star systems, as well as the lovely Eta Carinae, a very bright blue star with the highest known luminosity. WR 25 is the larger of the two stars and is thought to be binary (at least). WR 25 and Tr16-244 are of interest because they are somewhat rare, and are associated with star-forming nebulae, influencing the structure and evolution of galaxies. Tr16-244 is thought to actually be a triple star system, with the third star in the group taking tens or hundreds of thousands of years to orbit its companions!
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