Through computer simulations, the team from the US university discovered that the hydrogen atoms in Venus' atmosphere go into space through a process known as "dissociative recombination".
This phenomenon causes the planet to lose around twice as much water every day compared to previous estimates.
According to EurekAlert, Venus is extremely dry. If we were to spread all of Earth's water over our planet, we would get a liquid layer of approximately three kilometers. However, if we did exactly the same, but on Venus, we would end up with only three centimeters.
"Venus has 100,000 times less water than Earth, even though it's basically the same size and mass," explained Michael Chaffin, a scientist at the Laboratory for Atmospheric and Space Physics (LASP).
In this study, his team used computer models to understand Venus as a gigantic chemical laboratory, zooming in on the various reactions that take place in its atmosphere.
The results revealed that the HCO+ molecule - an ion composed of a hydrogen atom, carbon and oxygen - may be to blame for the planet's water leak.
But Venus wasn't always like this. Scientists suspect that billions of years ago, during its formation, the planet had almost as much water as Earth. However, a catastrophe has changed this reality.
Clouds of carbon dioxide in the atmosphere started the most powerful greenhouse effect in the Solar System, increasing surface temperatures to 482º Celsius. In this scorching process, all the water evaporated and turned into steam. The vast majority was then carried into space.
The biggest puzzle is that this evaporation cannot explain why Venus is still such a dry planet. Almost all the droplets left on the planet have also mysteriously disappeared and the culprit may even be HCO+.
In the planet's upper atmospheres, water mixes with carbon dioxide to form this molecule. HCO+ is constantly produced in the atmosphere, but the individual ions don't survive for long.
This is how electrons find these ions and split them in two. In the process, the hydrogen atoms disappear and can even escape completely into space - robbing Venus of one of the two components of water.
In this new study, the team calculated that the only way to explain Venus' dry state would be if the planet hosted larger than expected volumes of HCO+ in its atmosphere. But scientists have never observed HCO+ around Venus. This could be because scientists don't have the right instruments to detect the molecule.
The scientific article was recently published in Nature.
M. S. Chaffin
