Archive for October 9, 2011

Snow White And The Frozen Dwarf   27 comments

 

Snow White – World of Ice and Methane

Snow White (Photo Credit: NASA)US Astronomers at the California Institute of Technology (Caltech) have discovered that the dwarf planet 2007 OR10 known as Snow White –once a small volcanically active world firing slushy water ice from ancient volcanoes, and boasting an atmosphere, is today an icy, frozen, dead world, tinged red and enveloped in a thin layer of methane that is slowly slipping away to be lost into space.

Snow White — orbits the sun at the edge of the solar system and is about half the size of Pluto, making it the fifth largest dwarf planet. Part of a larger group of icy bodies called Kuiper Belt Objects (KBOs).Ironically Snow White has actually proved to be one of the reddest objects in the solar system.

However last autumn using a newly designed instrument called the Folded-port Infrared Echellette (FIRE), with the 6.5-meter Magellan Baade Telescope in Chile, Adam Burgasser, a former graduate student and now a professor at UC San Diego, and Wesley Fraser, postdoctoral scholar were shocked to find out although Snow White was indeed red, it’s surface was also covered in water ice.

“Water ice is not red! Although ice is common in the outer solar system, it’s almost always white~ Mike Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy.

One other dwarf planet that shares these characteristics is Quaoar, discovered in 2002. Slightly smaller than Snow White, Quaoar is still big enough to have had an atmosphere and a surface covered with volcanoes that sent-up and slush and ice, which as with Snow White flowed over the surface before freezing solid.

But smaller than dwarf planets like Pluto or Eris, it was unable to hold onto volatile methane, carbon monoxide, or nitrogen compounds as long. And two billion years after its formation Quaoar inevitably began to lose its atmosphere to space; now, and today all that remains is the space-irradiated methane which rests on the icy surface Quaoar’s, giving it a glowing reddish hue.

It is clear from indications on the spectrum of Snow White 2007 OR10 which clearly shows the presence of water ice that it too for the last ½ billion years it has followed in the footsteps of Quaoar, still and silent amongst the stars, slowly losing its atmosphere into space until now only a small part remains."

The existence of methane is still open to debate. But the use of a large telescope such as the Keck Observatory will show clearly whether methane exists on Snow White or not. If this proves to be so it will join Quaoar as one of only two dwarf planets that bridge the gap between the tiny selection of entities large enough to hold onto hazardous composites, and the smaller entities that constitute the vast majority of KBOs.