Oceans on Venus; a Very Long Time Ago; Maybe

"Oceans on Ancient Venus, Study Suggests"
Space.com (July 14, 2009)

"Venus may once have been more Earth-like, with volcanic activity and an ocean of water, a new map of the toasty planet's southern hemisphere suggests.

"The map comprises over a thousand individual images, recorded between May 2006 and December 2007 by the European Space Agency's Venus Express spacecraft. It gives astronomers another tool in their quest to understand why Venus is so similar in size to Earth and yet has evolved so differently.

"Because Venus is covered in clouds, normal cameras cannot see the surface, but Venus Express used a particular infrared wavelength to see through them.

"Although radar systems have been used in the past to provide high-resolution maps of Venus's surface, Venus Express is the first orbiting spacecraft to produce a map that hints at the chemical composition of the rocks...."

The article discusses, briefly, the possibility that the platforms on Venus may be similar, chemically, to the platforms we call continents on Earth. What's been found so far suggests that at least part of Venus' 'continents' are made of granite.

Robotic landers touched down on what may have been the ocean floors of Venus, and found the sort of basaltic rock we find under the organic stuff that coats the bottoms of Earth's oceans.

This article is a pretty good 'snapshot' of what's known about Venus, what's being discovered, and speculation about this near-twin of Earth.

More, about the (very remote) chance of finding living microbes in the clouds of Venus:

• "Microbes Could Travel from Venus to Earth"
  Space.com (August 11, 2008)
• "Life Zone on Venus Possible"
  Space.com (February 11, 2003)

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Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"