Astronomy Picture of the Day

Explanation: The first to orbit Mercury, the MESSENGER spacecraft came to rest on this region of Mercury's surface yesterday. Constructed from MESSENGER image and laser altimeter data, the scene looks north over the northeastern rim of the broad, lava filled Shakespeare basin. The large, 48 kilometre (30 mile) wide crater Janacek is near the upper left edge. Terrain height is colour coded with red regions about 3 kilometres above blue ones. MESSENGER'S final orbit was predicted to end near the centre, with the spacecraft impacting the surface at nearly 4 kilometres per second (over 8,700 miles per hour) and creating a new crater about 16 metres (52 feet) in diameter. The impact on the far side of Mercury was not observed by telescopes, but confirmed when no signal was detected from the spacecraft given time to emerge from behind the planet. Launched in 2004, the MErcury Surface, Space ENvironment, GEochemisty and Ranging spacecraft completed over 4,000 orbits after reaching the Solar System's innermost planet in 2011.