The Mystery's of Venus' Atmosphere: Giant Holes Examined (VIDEO)

Venus and Earth may be around the same size, but they're almost nothing alike. Now, scientists have found a few more differences; they've discovered giant holes in the electrically charged layer of the Venusian atmosphere, called the ionosphere, which paints a more complicated picture when it comes to Venus' magnetic environment.

"This work all started with a mystery from 1978," said Glyn Collinson, first author of the new paper describing the work, in a news release. "When Pioneer Venus Orbiter moved into orbit around Venus, it noticed something very, very weird-a hole in the planet's ionosphere. It was a region where the density just dropped out, and no one has seen another one of these things for 30 years."

That's why researchers set out to search for signatures of these holes in data from the European Space Agency's Venus Express. Launched in 2006, Venus Express is currently in a 24-hour orbit around the poles of Venus. The data reveals that these holes are actually far more common than previously realized, forming during both solar maximums and solar minimums.The next step, though, is to find out exactly how these holes form.

Venus' interaction with space is dominated by a stream of electrons and protons, a charged, heated gas called plasma. This stream zooms out from the sun and carries with it embedded magnetic fields. While Earth is protected from this radiation by its own strong magnetic field, Venus doesn't possess this type of protection. However, it does have an ionosphere, which is a layer of the atmosphere filled with charged particles.

The ionosphere is bombarded with the charged particles from the sun. This causes the Venusian ionosphere to be shaped as a thin boundary in front of the planet with a long, comet-like tail behind the planet. As solar winds impact the ionosphere, it piles up and creates a thin magnetosphere around Venus.

The holes themselves are likely two long, fat cylinders of low density material that stretch from the planet's surface to way out in space. A magnetic structure likely causes the charged particles to be squeezed out of these areas, like toothpaste through a tube. It's likely that this happens because magnetic field lines from the sun move toward Venus and the far sides of these lines then wrap around the planet, leading to two long straight magnetic field lines trailing directly behind Venus. These lines create the magnetic fields that squeeze the plasma out of the holes.

"We think that some of these field lines can sink right through the ionosphere, cutting through it like cheese wire," said Collinson. "The ionosphere can conduct electricity, which makes it basically transparent to the field lines. The lines go right through down to the planet's surface and some ways into the planet."

The findings reveal a bit more about how the Venusian atmosphere works. Currently, scientists plan to continue to explore exactly what causes these holes, which could lead to future discoveries when it comes to the atmospheres of other planets.

The findings are published in the Journal of Geophysical Research.

Want to learn more? Check out the video below, courtesy of NASA and YouTube.