Nov. 3, 2009: The MESSENGER spacecraft's third flyby of the planet Mercury has given scientists, for the first time, an almost complete view
of the planet's surface and revealed some dramatic changes in Mercury's comet-like tail.
"The new images remind us that Mercury continues to hold surprises," says Sean Solomon, principal investigator for the mission and director of the
Department of Terrestrial Magnetism at the Carnegie Institution of Washington.
NASA
And what sort of surprises? Well, something I find particularly interesting is the variance in Mercury's sodium exosphere "tail" between the
first and second flyby:
According to NASA, approximately 98% of Mercury's surface has now been surveyed and photographed, and many new
images are now available for us to pour over and test our brains for anomaly
recongnition.
Future flybys will focus on the poles of Mercury, as when Messenger goes into orbit.
The observations also show that calcium and magnesium in the exosphere exhibit different seasonal changes than sodium--a difference that
researchers do not yet fully understand. After MESSENGER enters Mercury orbit in 2011, it can make a continuous study of seasonal changes in all
exospheric constituents. That will provide key information on the relative importance of the processes that generate, sustain, and modify Mercury's
atmosphere.
. Amazing. More info about the calcium/magnesium emissions
HERE.
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