Electric wind: The destroyer of oceans and atmospheres

21 Jun 2016

NASA has discovered a very powerful ‘electric wind’ on Venus that strips the planet of any moisture or atmosphere. It means Earth 2.0 etc may need a rethink.

When looking for potentially habitable planets, NASA, ESA et al seek out places with similar orbits, similar distances from stars, similar temperatures and similar gravitational pulls as Earth.

What they don’t look for, though, is electric winds. This is important, as these winds could be the reason why planets like Venus seem so arid.

Venus is similar to Earth in many ways but, as it’s so much closer to the sun, any chances of oceans appearing on its surface are slim.

Its temperature of more than 460ºC means water would simply boil off, rising up as steam into the planet’s atmosphere. However, on Venus, even the steam is absent.

To find out why, NASA’s Glyn Collinson led a team of researchers investigating the comparable winds on Earth and Venus.

Electric winds are thought to be weak on most planets, far outfought by gravity. They are also present in many daily chores: towels sticking together in the tumble dryer, your phone’s electrical currents being forced through wires, etc.

Venus and Earth are similar sizes and have similar gravity, but Venus is bone dry and more than 10 times as hot as our home planet, via NASA/Conceptual Image Lab.

Venus and Earth are similar sizes and have similar gravity, but Venus is bone dry and more than 10 times as hot as our home planet, via NASA/Conceptual Image Lab

The team found that Venus’ electric wind is so strong that even water gets pushed away from the planet, meaning a rethink is needed for potentially habitable planets in the universe.

“We found that the electric wind, which people thought was just one small cog in a big machine, is, in fact, this big monster that’s capable of sucking the water from Venus by itself,” Collinson said.

“If you were unfortunate enough to be an oxygen ion in the upper atmosphere of Venus then you have won a terrible, terrible lottery.

“You and all your ion friends will be dragged off kicking and screaming into space by an invisible hand, and nothing can save you.”

New research suggests that the electric field around Venus may be a key factor in shaping what molecules exist in the Venusian atmosphere, including its lack of the molecules needed to make water, via NASA/Conceptual Image Lab

New research suggests that the electric field around Venus may be a key factor in shaping what molecules exist in the Venusian atmosphere, including its lack of the molecules needed to make water, via NASA/Conceptual Image Lab

Why Venus’ electric field is stronger than that of Earth is a bit of a mystery, though NASA and the ESA – who worked together on this – suggest it’s tied into the planet’s distance from the sun, “and the ultraviolet sunlight being twice as bright”.

Researchers are already looking at this on Mars, with more studies needed to “understand how this universal process works,” said Andrew Coates, leader of the electron spectrometer team at University College London in the UK and a co-author of the paper.

It may be the reason why Mars seems relatively dry, too. To better understand, this nice short video should explain all.

Main planet image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic

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