Astronomers found them using Hubble

Apr 30, 2010 06:36 GMT  ·  By
The Hubble telescope reveals Pluto as having alternating dark and bright spots on its surface
   The Hubble telescope reveals Pluto as having alternating dark and bright spots on its surface

A group of experts using the Hubble space telescope has recently uncovered a few peculiarities on the surface of Pluto, one of the outermost planets in our solar system. Datasets recovered from the famous observatory revealed the existence of alternating bright and dark spots on the celestial body, and many experts were puzzled as to what they might be. Currently, a team of investigators from the California Institute of Technology (Caltech) is proposing a new explanation for Pluto's features.

The group here believes that the dark spots are in fact accumulation of primitive organic compounds. They base their hypothesis on a closer analysis of the Hubble information. The idea makes sense when considering that experts already know that other, similar chemicals exist on the distant world. The new observations of Pluto were carried out last year, but the results of the investigation were only released this February, Space reports.

“We know there's methane on Pluto. Here's what we think happens: Sunlight hits the methane and breaks it apart into its chemical components – hydrocarbons. Over millions of years this process makes a dark reddish-brown oil or tar-like substance that sticks to the ground. These darker areas spread larger as they absorb more sunlight and cause additional frost to sublimate,” explains Caltech scientist and dwarf planet expert Mike Brown.

The team adds that the alternating bright patches may in fact be caused in frost generated by carbon monoxide. At this point, the temperatures on Pluto rank around minus 385 degrees Fahrenheit (minus 232 degrees Celsius), but they are still elevated following the planet's close approach to the Sun, late in the 1980s. Researchers say that seasonal variations occur much slower on the space rock than they do on Earth, primarily because it takes some 248 years for Pluto to complete a circle around the Sun.

“Until the mid-1980s, Pluto's northern hemisphere was tilted away from the sun for over 100 years, accumulating a substantial amount of frost. Now the northern hemisphere is coming into sunlight and appears, as shown in the Hubble images, to have been growing brighter,” adds Southwest Research Institute (SwRI) expert Marc Buie, who is also the leader of the study. “Now, Pluto is headed away from the sun again. It will gradually get colder and colder and its atmosphere will refreeze to its surface. In fact, that should have already started happening, but apparently it has not. It's a mystery,” Brown concludes.