The Last Month in Astronomy

SEP-10-2011 • GRAIL Launches • The NASA spacecraft launched toward the moon. GRAIL is taking the slow route, taking 3 and a half months. GRAIL is an acronym for Gravity Recovery and Interior Laboratory. Its mission is to study the interior of the moon by careful measurements including detailed mapping of the lunar gravity. It will do this by deploying two spacecraft in the same orbit and measuring relative velocity differences. This same technique has been used in Earth orbit by the GRACE mission since 2002. http://www.nasa.gov/mission_pages/grail/overview/index.html

SEP-07-2011 • Heads Up for UARS • The satellite UARS (Upper Atmosphere Research Satellite) was launched via the Space Shuttle in 1991. It is now ready to come home. But it won’t be an easy landing. Instead, it will break up and partially burn up in the atmosphere, probably before Halloween. This satellite measured ozone depletion, climate change and other atmospheric phenomena. It provided conclusive evidence of the role of chlorofluorocarbons in the creation of the ozone hole. It was decommissioned in 2005 and it was put into a “disposal” orbit so that it would not be a long-term navigation hazard for other spacecraft. The 7 ton satellite will break up into many pieces but some of those pieces will make it to the surface somewhere between 57 degrees North and 57 degrees South, i.e. almost anywhere. If you find a piece of the satellite do not try to sell it on EBay, don’t make it into a coffee table, in fact, don’t even touch it. http://cosmiclog.msnbc.msn.com/_news/2011/09/07/7651951-7-ton-nasa-satellite-set-to-fall Ed. Note: the spacecraft fell to earth around midnight PDT 9/24/2011

SEP-07-2011 • SN 2011fe • The supernova PTF 11kly (aka SN 2011fe) is the brightest SN visible in the Northern Hemisphere in about 40 years. It is in the Pinwheel Galaxy, M101. This galaxy is near Alkaid, the last star in the handle of the Big Dipper. As this is written it is between 11 and 10 magnitude and it may get brighter. An astronomer on the PBS news hour says that a 6 inch telescope can see it and binoculars with 20mm optics can also see it. (see photos on the left)http://www.pbs.org/newshour/bb/science/july-dec11/supernova_09-07.html

SEP-02-2011 • Eyes on the Solar System • NASA has released a new tool called “Eyes on the Solar System”. This web application gives the user a way to experience the solar system as they are on a NASA spacecraft. http://www.jpl.nasa.gov/news/news.cfm?release=2011-277

AUG-26-2011 • Hyperion Viewed • The Cassini spacecraft took new pictures of the irregularly shaped Saturnian moon Hyperion. This was Cassini’s second closest approach of this moon, a distance of 15,000 miles. The moon tumbles so chaotically that it was impossible to predict what face of Hyperion would be viewed during this encounter. The closest encounter was back in September of 2005. It’s next flyby will be twice as far as way and it will have occurred by the time you read this. http://www.jpl.nasa.gov/news/news.cfm?release=2011-266