PIA12366: Calcium and Magnesium in Mercury's Exosphere
Target Name: Mercury
Is a satellite of: Sol (our sun)
Mission: MESSENGER
Spacecraft: MESSENGER
Instrument: MASCS
Product Size: 1020 x 759 pixels (width x height)
Produced By: Johns Hopkins University/APL
Full-Res TIFF: PIA12366.tif (2.326 MB)
Full-Res JPEG: PIA12366.jpg (52.63 kB)

Click on the image above to download a moderately sized image in JPEG format (possibly reduced in size from original)

Original Caption Released with Image:

These figures show observations of calcium and magnesium in Mercury's neutral tail during the third MESSENGER Mercury flyby. The distribution of neutral calcium in the tail appears to be centered near the equatorial plane and the emission rapidly decreases to the north and south as well as in the anti-sunward direction. In contrast, the distribution of magnesium in the tail exhibits several strong peaks in emission and a slower decrease in the north, south, and anti-sunward directions. These distributions are similar to those seen during the second flyby, but the densities were higher during the third flyby, a different "seasonal" variation than for sodium. Studying the changes of the "seasons" for a range of species during MESSENGER's orbital mission phase will be key to quantifying the processes that generate and maintain the exosphere and transport volatile material within the Mercury environment.

Date Acquired: September 29, 2009
Instrument: Mercury Atmospheric and Surface Composition Spectrometer (MASCS)

These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy.

Image Credit:
NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Image Addition Date:
2009-11-05