Astro Blog

Source:   By Shelby Lin Erdman, CNN Excerpt: Fiery asteroids smash into Earth's atmosphere at such a stunning rate, .... A new NASA map [http://www.nasa.gov/jpl/bolide-events-1994-2013/#.VGjvfoeRl7o] from the ... Near-Earth Object Program [http://neo.jpl.nasa.gov/faq/] , reveals that more than 556 space rocks smashed into the atmosphere over a 20-year period between 1994 and 2013. ...The good news is most are small and harmless fireballs that disintegrate when they hit the atmosphere, .... An obvious exception occurred on February 15, 2013, when an asteroid as large as 55 feet in diameter with a mass of up to 10,000 tons crashed to earth in the Urals region in Russia, streaking through the morning sky in Chelyabinsk [http://www.youtube.com/watch?v=ZMT7rIhETJM] before landing in a fiery explosion that injured more than a thousand people and caused an estimated $33 million in damage . ...NASA said the Chelyabinsk asteroid was the largest to hit the Earth during the agen...

Source:   Kenneth Chang, The New York Times Excerpt: In a technological feat that gives scientists their first opportunity to dig into a remnant of the early solar system, the European Space Agency’s Rosetta mission successfully placed a small spacecraft on the surface of ... Comet 67P/Churyumov-Gerasimenko, a 2.5-mile-wide ball of rock, ice and dust moving faster than 40,000 miles an hour,....” The agency’s director general, Jean-Jacques Dordain said at a news conference... “Not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a probe to a comet’s surface.” ...For scientists, one of the central mysteries that Rosetta will explore is whether Earth’s oceans are filled with melted comets ... slamming into the Earth early on.... See also interview with Joel W. Parker , planetary scientist.... http://www.nytimes.com/2014/11/13/science/space/european-space-agencys-spacecraft-lands-on-comets-surface.html

Source:   4.1, 7.2, 8.3 Excerpt: …scientists… revealed new data uncovered by NASA's Lunar CRater Observation and Sensing Satellite, or LCROSS, and Lunar Reconnaissance Orbiter, or LRO. …evidence that the lunar soil within shadowy craters is rich in useful materials, and … has a water cycle. Scientists also confirmed the water was in the form of mostly pure ice crystals in some places. …"NASA has convincingly confirmed the presence of water ice and characterized its patchy distribution in permanently shadowed regions of the moon," said Michael Wargo, chief lunar scientist…. The twin impacts of LCROSS and a companion rocket stage in the moon's Cabeus crater on Oct. 9, 2009, lifted a plume of material that might not have seen direct sunlight for billions of years. As the plume traveled nearly 10 miles above the rim of Cabeus, instruments …made observations of the crater and debris and vapor clouds. After the impacts, grains of mostly pure water ice were lofted into...

Source:   NASA RELEASE 14-236    Using data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL), mission scientists have solved a lunar mystery almost as old as the moon itself. Early theories suggested the craggy outline of a region of the moon’s surface known as Oceanus Procellarum, or the Ocean of Storms, was caused by an asteroid impact. ... However, mission scientists studying GRAIL data believe they have found evidence the craggy outline of this rectangular region -- roughly 1,600 miles (2,600 kilometers) across -- is actually the result of the formation of ancient rift valleys.  ...rifts are buried beneath dark volcanic plains on the nearside of the moon and have been detected only in the gravity data provided by GRAIL. ...The findings are published online in the journal Nature. Another theory arising from recent data analysis suggests this region formed as a result of churning deep in the interior of the moon that led to a hi...

Try out this interactive simulation for Crater Impacts. Keywords: asteroid, crater, impact, meteoroid http://simulator.down2earth.eu/ 

NASA RELEASE 14-241 Excerpt: Scientists have found evidence of plate tectonics on Jupiter’s moon Europa. This indicates the first sign of this type of surface-shifting geological activity on a world other than Earth. ...While examining Europa images taken by NASA’s Galileo orbiter in the early 2000s, planetary geologists Simon Kattenhorn, of the University of Idaho, Moscow, and Louise Prockter, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, discovered some unusual geological boundaries. ...When Kattenhorn and Prockter rearranged the icy terrain in the images, they discovered about 7,700 square miles (about 20,000 square kilometers) of the surface were missing in the moon’s high northern latitudes. Further evidence suggested the missing terrain moved under a second surface plate -- a scenario commonly seen on Earth at plate-tectonic boundaries. Kattenhorn and Prockter saw ice volcanoes on the overriding plate, possibly formed throug...

A new blog named "Planetary Blog" has replaced the old AstroBlog as of 2014 Sept 1. All AstroBlog posts before that date may still be found at the old blog site: We are working on transferring the old blog entries to the new one. Thanks for your patience. http://www.fossweb.com/astroblog