Venus's Lost Oceans



Did Venus once have oceans? Results from ESA's Venus Express spacecraft suggest it had and that the hot hell planet of today may have evolved from a more temperate past. The spacecraft's analysis of Venus's atmosphere ( http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Was_Venus_once_a_habitable_planet ) suggests that Venus was once much wetter than it was now. The missing water was lost to space but the spacecraft's results suggest echoes of the lost oceans remain in the water vapour still in the atmosphere. Venus Express's map of the surface of Venus ( http://www.esa.int/Our_Activities/Space_Science/Venus_Express/New_map_hints_at_Venus_wet_volcanic_past) also suggests that the highland areas might be continents and that plate tectonics might oncenhave operated on the planet. The results are controversial and modelling by Japanese scientists has suggested that owing to it's closeness to the sun Venus may have never had liquid water (http://www.csmonitor.com/Science/2013/0529/Why-doesn-t-Venus-have-oceans-Study-offers-intriguing-new-theory.) but the only way to find the answer is to put a lander on Venus and examine the rocks.

"Of all the planetary-science questions we have, the question of why are the Earth and Venus different is the most gigantic and fundamental unanswered question we've got," says Lindy Elkins-Tanton, director of the Carnegie Institution of Washington's Department of Terrestrial Magnetism and a researcher who studies planet evolution. " If scientists want to say they know anything about what makes for a habitable planet, she says, "We'd better be able to answer that one."

Surely even at this time of budget cuts a mission to Venus, the easiest and the cheapest planet to get to and land on should be a scientific priority?