New data show amazing atmospheric phenomena at the planet

Oct 1, 2011 00:11 GMT  ·  By
FIPS found that at the magnetic cusps near the planet's poles, the solar wind is able to bear down on Mercury enough to blast particles from its surface into its wispy atmosphere
   FIPS found that at the magnetic cusps near the planet's poles, the solar wind is able to bear down on Mercury enough to blast particles from its surface into its wispy atmosphere

The innermost planet in our solar system is being subjected to a constant beating at all times. Intense solar winds, which are undiluted due to the close proximity between the two bodies, literally sandblast Mercury's poles, triggering phenomena similar to the ones that generate auroras on Earth.

The new conclusions belong to a study that was published in the September 30 issue of the top journal Science, alongside six other papers detailing various interesting processes discovered on the planet.

These new data were collected by the 485-kilogram (1,070-pound) NASA MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) space probe, which has been orbiting the innermost planet since March 18, 2011.

According to the new study, it would appear that the primary targets of solar winds are the sodium and oxygen particles that make up the exosphere surrounding Mercury. The planet cannot hold on to a proper atmosphere, so its air is only made up of rarefied chemicals.

As these particles are kicked higher up into the exosphere, they are electrically charged by the solar winds, causing them to display bright lights similar to the phenomenon called auroras here on Earth.

Data used for this particular study were collected using the Fast Imaging Plasma Spectrometer (FIPS) instrument, which was developed and constructed at the University of Michigan (U-M). The tool was recently able to compile the first global measurements of Mercury's exosphere and magnetosphere.

Ultimately, researchers hope to be able to figure out the exact nature of the relationships that developed between the planet and our parent star. Even before MESSENGER started its mission, scientists had some theories on the origins and composition of particles in Mercury's surroundings.

“We had previously observed neutral sodium from ground observations, but up close we’ve discovered that charged sodium particles are concentrated near Mercury’s polar regions where they are likely liberated by solar wind ion sputtering, effectively knocking sodium atoms off Mercury’s surface,” Thomas Zurbuchen says.

The expert, who holds an appointment as a professor in the Department of Atmospheric, Oceanic and Space Sciences and Aerospace Engineering at the U-M College of Engineering, is the leader of the FIPS project.

“Our results tell us is that Mercury’s weak magnetosphere provides very little protection of the planet from the solar wind,” he adds, explaining that such studies also shed more light onto how the Sun itself functions within.

“We’re trying to understand how the sun, the grand daddy of all that is life, interacts with the planets. It is Earth’s magnetosphere that keeps our atmosphere from being stripped away. And that makes it vital to the existence of life on our planet,” FIPS operations engineer and U-M PhD student Jim Raines adds.