The Last Month in Astronomy

MAR-11-2010 • Earth knocked for a loop • The 8.8 magnitude earthquake that hit Chile in February was so strong that it might have shifted the axis of Earth. The change in the axis is about 8 cm according to Richard Gross of JPL. “The figure axis defines not how Earth is tilted, but rather how it is balanced.” Is this a big deal? Well, the “figure axis” moves about 10 cm per year as a result of the Ice Age rebound, a change in the crust and mantle of the Earth since last ice age ended 11,000 years ago. http://science.nasa.gov/headlines/y2010/11mar_figureaxis.htm

MAR-11-2010 • No differentiation in Titan • Cassini’s low swoops over Titan have generated a set of gravity maps of the Saturnian moon. The results show that Titan has not differentiated. Scientists say that the interior of Titan was (and is) too cold to split into separate layers of rock and ice. This in turns suggests that Titan formed rather slowly. http://www.jpl.nasa.gov/news/news.cfm?release=2010-084&rn=news.xml&rst=2516

MAR-10-2010 • Water on Moon • Larry Taylor once said that if water is found on the Moon he would eat his shorts. The latest evidence of that water is found in research done by ... Larry Taylor. To celebrate, his colleagues baked a cake decorated with boxer shorts, white with pink polka dots. The new research goes farther than the recent water discoveries. This research shows the moon has probably always held water and that comets play a bigger role in water delivery than was previously supposed. http://www.nature.com/news/2010/100309/full/464150a.html or try http://xenophilius.wordpress.com/2010/03/10/

MAR-09-2010 • Fastest stellar pair • What is the shortest known orbital period of any pair of stars? If it takes you more than 5.4 minutes to answer, one orbit of HM Cancri will be complete. This pair was discovered 10 years ago but it took careful study of the spectra to measure the speed. “This type of observation is really at the limit of what is currently possible. Not only does one need the biggest telescopes in the world, but they also have to be equipped with the best instruments available” according to Paul Groot of the Radboud University Nijmegen in the Netherlands. These measurements were done at Keck. http://keckobservatory.org/index.php/news/keck_telescope_confirms_smallest_known_star_duo/

MAR-03-2010 • Primitive Star Found • Astronomers have found a star that dates back to the second generation of stars formed after the Big Bang. The star is in the dwarf galaxy Sculptor which is 290,000 light-years away. The presence of this star supports the theory that galaxies from by swallowing up dwarf galaxies. That’s because this primitive star has a similar chemical make-up to the oldest stars in the Milky Way. The star is S1020549 and it has a metallicity that is 6000 times lower than the sun. It is 5 times lower than any star previously found in a dwarf galaxy. http://www.cfa.harvard.edu/news/2010/pr201003.html

FEB-21-2010 • STS-130 Lands • The shuttle Endeavour completed a successful mission with a landing at KSC. This mission installed the Tranquility Node and a cupola for making observations of Earth. The next mission for Endeavour is set for late July when it will deliver the Alpha Magnetic Spectrometer. That mission will also be the last for Endeavour. The next shuttle mission is Discovery’s next to last mission currently scheduled for April 5. http://spaceflightnow.com/shuttle/sts130/status.html

FEB-15-2010 • Saturn Edge-On • Hubble took some pictures of Saturn edge-on last year and they have just been released. The image shown above show aurorae in both the north and south poles. The blue color is probably due to Rayleigh scattering, the same effect that makes a midday clear sky appear to be blue. http://hubblesite.org/newscenter/archive/releases/2010/09/image/a/