Degas, Mariner 10, The Nine (8) Planets, Bill Arnett
http://www.nineplanets.org/

It’s that time again!  On September 29, 2009, Messenger will make it’s 3rd Mercury flyby, having traveled more than 3.5 billion miles in over five years.  The planned flyby on the 29th will be Messenger’s 6th planetary flyby; two of Venus, two of Mercury, and one of Earth.

South polar mosaic, http://nssdc.gsfc.nasa.gov/planetary/image/mercuryfact_bg.gif

As a result of Messenger’s last two flybys, more than 90% of Mercury’s surface has been imaged.  In addition to planetary flybys, in March of 2011, Messenger will become the first spacecraft to enter into orbit around Mercury.

You can find Messenger’s (and Mercury’s) location in the solar system at any given time with:  http://messenger.jhuapl.edu/whereis/index.php

Mercury is the smallest planet in the solar system, and is much like the moon in appearance.  It is heavily cratered with no natural satellites and no substantial atmosphere.  Astronomers recorded observations of Mercury back before the first millennium BC, when it was initially thought to be two planets; Apollo (visible only at sunrise), and Hermes (visible only at sunset).  Mercury’s surface temperature averages 442.5K, with ranges from100K to 700K between the equator and the poles.  Despite the generally high surface temperature, there is strong evidence to suggest that ice exists on Mercury on the floors of deep craters at the poles.