There is a hole in the atmosphere of Mars that opens up every two years and dumps water into outer space.
Previous observations have revealed that Mars has water vapor high in its atmosphere, but how it got there remains a mystery to scientists. Like Earth, the Red Planet has a middle layer in its atmosphere that serves as a barrier to prevent gas from rising even further.
"The Martian middle atmosphere is too cold to sustain water vapor," the researchers wrote in the study published in the American Geophysical Union's Geophysical Research Letters.
Through computer simulations, a team of researchers from Germany and Russia identified two atmospheric processes unique to the Red Planet. These could explain how the once waterlogged world lost most of its water and offer clues as to how Earth manages to keep its reserve.
The Water Cycle Of Mars
Every two years, when the Martian Southern Hemisphere experiences summer, water vapor rises from the lower to the upper atmosphere. The team explained that during that time, a window opens, allowing water vapor to escape from the lower to the upper atmosphere.
The infamous dust storms of the Red Planet can also move water into the upper atmosphere. Whenever a dust storm occurs, it blocks light from the surface. However, whatever light is blocked warms the atmosphere, creating a condition suitable to move water around. Tiny particles of water ice form around dust and float into the upper atmosphere.
Once the water passes through the middle layer, two things happen. Some of the water gets carried toward the north and south pole where it is deposited back. The rest, however, gets subjected to the ultraviolet radiation of the sun, splitting water into hydrogen and oxygen. The hydrogen escapes into outer space.
How Mars Lost Its Water
Once upon a time, ancient Mars had rivers and lakes. However, billions of years ago, it lost all of its water and to this day, Earth's next-door neighbor continues to leak hydrogen into space.
The researchers believe that this odd water cycle turned the Red Planet into what it is today.
"Apparently, the Martian atmosphere is more permeable to water vapor than that of the Earth," said Paul Hartogh, one of the authors of the study. "The new seasonal water cycle that has been found contributes massively to Mars' continuing loss of water."
