Astronomy Picture of the Day

Explanation: Mars Pathfinder is nearing the end of its 7 month journey. The robot spacecraft is scheduled to use parachutes, rockets, and airbags to "bouncedown" on the red planet tomorrow - July 4th. This Hubble Space Telescope image of Mars was taken a few days ago to check on the weather. The pathfinder landing site, on the ancient floodplain Ares Vallis, is just right of centre - 500 miles southeast of where Viking 1 landed in 1976. Along with the martian north polar cap, some water ice clouds are visible in both the northern and southern hemisphere. About 600 miles south of the landing site a dust storm can be seen as a brownish ribbon stretching through the the Valles Marineris, a continent sized canyon system. Fortunately, the dust storm is not expected to seriously affect operations at the landing site.