Astro Blog

Source:    European Southern Observatory  Release eso1142 Excerpt: In November 2010, the distant dwarf planet Eris passed in front of a faint background star, an event called an occultation. …Occultations provide the most accurate, and often the only, way to measure the shape and size of a distant Solar System body. …The combined observations from the two Chilean sites indicate that Eris is close to spherical. …Eris… discovery was one of the factors that led to the creation of a new class of objects called dwarf planets and the reclassification of Pluto from planet to dwarf planet in 2006. Eris is currently three times further from the Sun than Pluto. …Eris’s newly determined diameter stands at 2326 kilometres, …This makes its size better known than that of its closer counterpart Pluto, which has a diameter estimated to be between 2300 and 2400 kilometres. …The motion of Eris’s satellite Dysnomia was used to estimate the mass of Eris …27% heavier than Pluto … Eris i...

Source:   Europlanet  Press Notice EPSC11/13 Excerpt: Uranus’s highly tilted axis [98 degrees] makes it something of an oddball in our Solar System. The accepted wisdom is that Uranus was knocked on its side by a single large impact, but new research to be presented on Thursday 6th October at the EPSC-DPS Joint Meeting in Nantes rewrites our theories of how Uranus became so tilted and also solves fresh mysteries about the position and orbits of its moons. By using simulations of planetary formation and collisions, it appears that early in its life Uranus experienced a succession of small punches instead of a single knock-out blow. This research has important ramifications on our theories of giant planet formation. www.europlanet-eu.org/outreach/index.php

Source:  NASA  Excerpt:  …Astronomers have found a new cosmic source for the same kind of water that appeared on Earth billions of years ago and created the oceans. The findings may help explain how Earth's surface ended up covered in water. New measurements ...show that comet Hartley 2... contains water with the same chemical signature as Earth's oceans.  www.nasa.gov/home/hqnews/2011/oct/HQ_11-338_Herschel_Comet_Water.html

Source:   Europlanet  Press Notice EPSC-DPS Joint Meeting 11/05 Excerpt: Global and high resolution mapping of Enceladus confirms that the weather forecast for Saturn's unique icy moon is set for ongoing snow flurries.  The superfine ice crystals that coat Enceladus's surface would make perfect powder for skiing, according to Dr Paul Schenk of the Lunar and Planetary Institute….The ghost-like features on the plains and the slope breaks on steep canyon walls are interpreted as due to the formation of a loose poorly-consolidated material lying on top of more solid crustal ices….  The layer is on average roughly 100 meters (350 feet or so) deep in this area.   …The models of plume deposition indicate that the rate of deposition on Enceladus is extremely slow by Earth standards, less than a thousandth of a millimetre per year.  To accumulate 100 meters of deposits would require a few tens of millions of years or so.  …Without replenishment, the...

Source:    NSF Press Release 11-212   Excerpt: Astronomers ...discussed details of the first scientific observing cycle with the Atacama Large Millimeter/submillimeter Array or ALMA. ... the first test image released by the ALMA collaboration...a composite of views of the "Antennae Galaxy" was taken with several different types of telescopes, including test data from ALMA. www.nsf.gov/news/news_summ.jsp

Source:   NASA Excerpt: …A new scientific model suggests Saturn's rings formed from the shredding of an ancient moon's outer envelope before it finally collided with Saturn.  solarsystem.nasa.gov/yss/display.cfm