Mickey Mouse on Mercury
September 19, 2012

Mercury MESSENGER Finds The Planet Is Truly Of Different Origins

Lee Rannals for redOrbit.com - Your Universe Online

After spending the last year-and-a-half orbiting Mercury, NASA's MESSENGER spacecraft is revealing new information about the planet that lies closest to the sun.

New x-ray data from the space probe shows that the planet contains high levels of magnesium and sulfur on its surface, making its composition quite different than that of other planets.

MESSENGER's X-ray spectrometer shows a planet whose northern volcanic plains formed through upwellings of rocks that are also unique to Mercury.

The older terrain on Mercury has higher ratios of magnesium to silicon, sulfur to silicon, and calcium to silicon, but lower ratios of aluminum to silicon.

The latest data consists of 205 measurements of the surface composition from the X-ray spectrometer, which focuses on the large expanse of smooth volcanic plains at high northern latitudes and surrounding areas that are higher in crater density and older than the northern plains.

The concentration of sulfur observed on the surface is about 10 times that seen on Earth, according to Shoshana Weider, a researcher at the Carnegie Institution of Washington.

The researchers published their findings recently in the Journal of Geophysical Research.

The Planetary Data System (PDS) released data collected during MESSENGER's seventh through twelfth month orbit around Mercury back in early September. This release made images and measurements of Mercury available to the public.

MESSENGER first reached Mercury in March 2011, and it is only the second spacecraft to reach the planet and orbit it.

Mercury is about 5 percent the size of Earth, and it revolves around the sun every 88 days. The planet has a surface temperature that reaches up to 800 degrees Fahrenheit.