Electrical Winds Can Remove Oceans And Atmospheres From Planets

Scientists have long been trying to find an answer to explain what has happened to the oceans and atmospheres of different earth “like” planets. NASA feels like they have finally figured it out.

Scientists have found that Venus- which is considered the most closely related planet to Earth, has an “Electric wind” in its upper atmosphere that accelerates the heavy ions from water molecules to speeds greater than the planet’s escape velocity, causing them to fly off into space.

 

“It’s amazing, shocking,” said Glyn Collinson, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We never dreamt an electric wind could be so powerful that it can suck oxygen right out of an atmosphere into space. This is something that has to be on the checklist when we go looking for habitable planets around other stars.”

Venus is very similar to our Earth in regards to mass and volume, but it has an atmosphere that is much thicker than Earths along with a surface temperature of about 460°C (860°F), way too hot to be habitable.

The atmosphere also has significantly less water, between 10,000 and 100,000 times. Solar winds was the likely explanation for where Venus’s oceans went , but the instruments aboard ESA’s Venus Express showed that the planetary electric field has a greater impact on Venus, than previously thought.

“The electric field is started when electrons are produced by sunlight hitting the atmosphere of Venus,” Professor Andrew Coates, co-author of the study, said.

“These electrons can move very quickly along the magnetic field generated by the solar wind and doing so they pull the ions with them, so they create an electrical pull.”

“Venus Express has found possible signs of active volcanism,” added Coates. “So, it could be that the atmosphere is being replenished by these volcanoes but only to then be lost into space.”

The biggest difference between Venus and Earth could be that the distance to the sun is a lot closer for Venus, thus having more of its atmosphere particles being energized.

Venus is not the only object in the Solar System losing material. Mars has lost most of its atmosphere, and Saturn’s moon Titan loses 7 metric tons (7.7 US tons) per day.

“All these objects in the Solar System, they are losing materials from their atmosphere to space,” said Coates. “And we are trying to understand how this loss occurs. This is an important mechanism of the atmospheric evolution of an object through time.”

Understanding how planets lose their atmosphere is important not only for our Solar System but for human colonization of other planets.

 

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