Mercury's Dark Side is Unmasked by Messenger

If you pay much attention to many other space/astro news sites or blogs then you most likely already know that NASA's MESSENGER craft has recently flown by Mercury and taken the first ever pictures of one of its hemispheres.

When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed.

The MESSENGER probe flew closer to the first rock from the sun than any previous man-made craft, around 124 miles from its surface. The image on the right was taken at a distance of about 17,000 miles, about 80 minutes after MESSENGER's closest approach to the planet, using a filter sensitive to light near the red end of the visible spectrum. NASA has also said that more pictures will be on the way, so as soon as I get them I will put them up.

Image: Mercury, hidden hemisphere. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

More Info: MESSENGER homepage
Picture Perfect Little Mercury
The Side Nobody has Seen

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NASA spacecraft has a date with Mercury next week

Next week NASA's MESSENGER probe will skim just 124 miles (200 km) above Mercury's uncharted hemisphere. The craft's closest pass will occur at 2:04 p.m. EST (1904 GMT) on Monday. It will conduct three flybys that will help it reduce speed and ultimately enter Mercury's atmosphere. Launched in August of 2004 MESSENGER will be the first spacecraft to visit Mercury since NASA's Mariner 10 probe swung past the planet three times between 1974 and 1975. MESSENGER will enter orbit in 2011 for a one-year science campaign. The mission will have a total price tag of around $446 million and will probe the secrets of Mercury, from its wispy thin atmosphere to an unusually dense interior. The mission will also generate the first maps of some 55 percent of the planet's rocky surface. The craft will travel a total distance of 4.9 billion miles to get to Mercury. Over half of the planet hasn't been mapped and the flyby will take the first photos of it in 33 years. The team from NASA is anxious for the first of the nearly 1200 photos to start flowing in.

Here is a picture MESSENGER took from around 3 million miles away from Mercury:

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