Views of Mercury's surface from space
(click for larger image)
NASA has published photos of Mercury, taken from a probe that traveled within 125 miles of the planet's surface.
The Messenger mission orbited the planet Oct. 6, around 4:40 a.m. ET, for the second time this year. The craft captured hundreds of photos and collected data for transmission early Tuesday morning. One of the images captured Kuiper, a crater on Mercury that scientists first identified during the Mariner 10 mission about 30 years ago.
The images captured the first spacecraft views of Mercury's surface to the east of Kuiper. The images show a large pattern of rays beginning in the northern parts of Mercury and stretching south of the crater.
NASA believes that the rays come from a young crater never previously captured by spacecraft. Although it's the first time the crater was captured in photographs, Earth-based radar had detected it before the Messenger's flyby. A second, more prominent, crater, southeast of Kuiper, has also appeared in photographs for the first time.
Messenger is the first mission sent to orbit Mercury. It launched in 2004. NASA hopes the probe will become the first spacecraft ever to orbit Mercury beginning in March 2011.
A key Messenger design element deals with the intense heat of Mercury. The sun is up to 11 times brighter than we see on Earth, and surface temperatures can reach 450 degrees Celsius.
Messenger is made of a graphite epoxy material. It's designed to operate at room temperature behind a sunshade of heat-resistant ceramic cloth, which allows it to withstand intense heat from the sun on Mercury. It gains power from solar panels and a nickel-hydrogen battery. The craft also contains a 25-MHz processor and a 10-MHz fault-protection processor.
Star-tracking cameras and an Inertial Measurement Unit made up of four gyroscopes and four accelerometers, with six backup Digital Solar Sensors, four reaction wheels, and small thrusters help the spacecraft orient itself.