Tuesday, December 16, 2008

Earth and Moon from space


The Voyager 1 image I posted earlier started me wondering about how many times the Earth-Moon system has been imaged or photographed from space. The Voyager image quoted was the first image from deep space, that is, out side the Earth-Moon system, however, it was not the first image of the system, that honour goes to Lunar Orbiter 1.

The image was taken 16:36 GMT on 23 August, 1966 and shows the eastern far side of the moon; the Earth is 380,000 kms away and the terminator (day-night boundary) runs through Odessa, Istanbul, and slightly west of Capetown. To see the a larger version click on the image.

The Lunar Orbiters were sent into space by the US during 1966 and 1967 to photograph the entire surface of the moon at close range. NASA before the Apollo Program could proceed needed to identify potential landing sites, and it also needed to decide how safe those sites were. Lunar Orbiter was a reconnaissance mission designed to do this. Once the program was over all five machines were crashed into the lunar surface so as not to present a hazard to the Apollo spacecraft. As a result of the program 99% of the lunar surface was photographed at a resolution of around 100 meters or less. Information on the Orbiter Program cam be found at NASA (http://nssdc.gsfc.nasa.gov/planetary/lunar/lunarorb.html)

The NASA-JPL Photojournal (http://photojournal.jpl.nasa.gov/index.html) allows the public world wide to see many of the images taken by US (and many non-American) spacecraft, click on the image map or press the "Search Methods" tab at the bottom of the page.

Image credit:
© NASA/GSFC, 1966.

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