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The Last Month in Astronomy


MAR-09-2011 • Discovery’s last landing • The Space Shuttle Discovery completed its last planned mission. Discovery is now expected to go take up residence in the Smithsonian Air and Space Museum. However, at this time that is not guaranteed. The next shuttle flight, Endeavor’s final flight, is scheduled for April 19.

MAR-08-2011 • Enceladus Power • New estimates of the power fueling the water geysers on Enceladus suggest that it is the equivalent of 20 coal-fueled power stations. This new estimate is 10 times higher than the previous estimate.That earlier pegged the power at 1.1 gigawatts from the tidal interactions with the moon Dione and another 0.3 gigawatts from radioactivity. The newer number, 15.8 gigawatts, is based on observations from 2008 covering the south polar area. The higher output increases the likelihood of liquid water below the surface.

MAR-04-2011 • No success, no Glory • The NASA mission named Glory failed ignominiously when the fairing, a protective shell around the intended satellite, failed to separate from the rocket. After more than 50 years of experience in launching rockets, the idea that NASA cannot get the cover to pop off is galling. But it is all the worse when the same thing happened on the same Taurus XL rocket dooming the Orbiting Carbon Observatory in 2009. After the OCO failure, an Investigation board developed a corrective action plan and the fairing separation was radically different on this mission. However, the final effect was exactly the same. The result of these two launches is nothing except losses of $700 million.

MAR-03-2011 • Sunflower in IR • The Spitzer telescope team has released a new photo of M63, the Sunflower galaxy. This photo shows the dust lanes in the galaxy’s spiral arms. To make this image, light with a wavelength of 3.6 microns is printed as blue; 4.5 micron light is printed as green; and 8 microns becomes the red component. Then the starlight measured at 3.6 microns is subtracted from the 8 micron image to produce a result that enhances the dust features.

FEB-24-2011 • Superconductor in space • The NASA Chandra X-ray observatory is studying the neutron star that is in the supernova remnant Cassiopeia A. One finding is that Cas A has cooled by about 4% over the last 10 years, a surprisingly large amount. In a neutron star the pressure is so high that electrons are forced to merge with protons, thus creating neutrons. “The rapid cooling in Cas A’s neutron star ... is the first direct evidence that the cores of these neutron stars are, in fact, made of superfluid and superconducting material.” A superfluid is a friction-free state of matter. Superconductors allow electric current to flow with no resistance.

FEB-21-2011 • Taking the universe’s measure • Quick, what astronomical instrument gives the highest resolution, Hubble, Keck with adaptive optics, Chandra? The answer is the Very Long Baseline Array Telescope (VLBA), a radio telescope. The VLBA uses 10 25-meter diameter dish antennas distributed from Hawaii to St. Croix to the Caribbean and operated by the NRAO in Socorro, New Mexico. The antennas work together allowing them to act like an antenna that has the diameter equal to the longest distance between dishes. The latest measurements place galaxy NGC 6264 at a distance of 450 million light-years with an uncertainty of 9%. The previous longest direct measurement of a galaxy was 160 million light-years.

FEB-16-2011 • Herschel and Dark Matter • The Herschel Space Observatory, a project led by the ESA but strongly supported by NASA, has made an important determination about dark matter and galaxy formation. According to Asantha Cooray (from U.C. Irvine), “If you start with too little dark matter, then a developing galaxy would peter out. If you have too much, then gas doesn’t cool efficiently to form one large galaxy, and you end up with lots of smaller galaxies.” The right amount of dark matter is a mass equal to about 300 billion suns.

FEB-14-2011 • New spectrograph complements Kepler • A new spectrograph has been built at the Harvard-Smithsonian Center for Astrophysics. The spectrograph is designed to detect the stellar wobbles created by earth-size planets that closely orbit their stars. The idea is to use this instrument to better characterize the planets found by the Kepler spacecraft.


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