Few probably remember the August 2004 launch of NASA’s MESSENGER spacecraft, but the little craft recently sent back some unforgettable images.
MErcury Surface, Space ENvironment, GEochemistry, and Ranging probe has completed the first of three fly-by maneuvers past the planet Mercury. The craft will slow itself by making two more passes before attempting to insert itself into orbit around the planet in March 2011. When the mission completes, we will have a complete surface map of Mercury as well as extensive surface composition data.
No craft has been sent to Mercury since Mariner 10 in 1975, which was only able to take images of one hemisphere. Today, NASA released the first ever image of the other hemisphere.
Mercury is the closest planet to our sun, and much about it remains a mystery. Due to the proximity to the sun and extremely thin atmosphere, the planet has enormous temperature ranges from about 80 Kelvin on the dark side to 700 Kelvin on the sun-facing side. These conditions make finding life on Mercury very unlikely. There is evidence however that some of the craters near the poles, where due to axial tilt the temperature fluctuations are less severe, contain water-ice. This was discovered in the early 1990’s using the Very Large Array radio observatory. There is no doubt that MESSENGER will bring forth a host of facts about one of our solar system’s most intriguing objects.