Water, water (or ice) everywhere—that’s the refrain this year. This week we covered the study declaring that the moon was home to perhaps 100 times more water than previously thought, and it was just two months ago that sky-watchers spotted the first frosty asteroid out in the Asteroid Belt. Now, in a study in Nature, a team of astronomers says they’ve found another icy surprise in our solar system: a bright shiny object way out in the Kuiper Belt.
The Kuiper Belt is that mess of objects orbiting the sun out beyond Neptune, but not as far as the Oort Cloud (once-proud Pluto is a Kuiper Belt object). There are plenty of icy bodies out there, including Pluto. But what doesn’t make sense about this one, KBO 55636, is how it stayed so pristine after a billion years of floating alone. MIT’s James Elliot, who led the study, says the object’s albedo, or reflectivity, is striking:
“That turned out to be very high, almost 90 percent… That’s consistent with it having a very highly reflective surface like water ice.” The finding was surprising because such old, distant bodies tend to have weathered, dull surfaces. “Objects orbiting that far out in space get generally darkened by accumulating dust… We don’t have an explanation for how it could stay so pristine” [Space.com].
A cold and sterile chunk of rock orbiting the sun in the vicinity of Neptune and Pluto has been officially named Makemake, after a Polynesian god. The International Astronomical Union (IAU) has also designated Makemake the solar system‘s fourth dwarf planet and third “plutoid,” as researchers’ new aptitude for locating small orbital bodies has required a new and controversial system of classification.
Astronomers discovered Makemake (pronounced MAH-keh MAH-keh)… in 2005 and believe its surface is covered by a layer of frozen methane. It is bright enough to be seen by a high-end amateur telescope [SPACE.com]. Researchers say it’s about two-thirds the size of Pluto.