ESA and NASA spacecraft to view Venus

Paris -- Two spacecraft this week will provide astronomers around the Earth close-up images of Venus, showing the same locations a short time apart.

The European Space Agency's Venus Express, in orbit around Venus since April 11, 2006, will be joined for a few hours Wednesday by the National Aeronautics and Space Administration's Messenger (MErcury Surface Space ENvironment GEochemistry and Ranging mission) spacecraft en route to Mercury.

Scientists said the direct, two-point measurements of some planetary phenomena have great potential to offer new science.

At the time of closest approach, Messenger will be flying over Venus at an altitude of approximately 209 miles. At the same time, Venus Express will be behind Venus but looking at the same regions observed by Messenger before and after the fly-by. That will allow scientists to compare data obtained by the two spacecraft within only a short difference in time. Of particular interest will be observations of Venus' cloud deck, plasma environment, atmosphere and its oxygen airglow and surface.

Venus Express, ESA's first mission to Venus, was launched Nov. 9, 2005. Messenger was launched Aug. 3, 2004, and is expected to reach Mercury in 2011.

Copyright 2007 by United Press International.