Venus is leaking carbon and oxygen—and scientists don't know why

"This is the first time that positively charged carbon ions have been observed escaping from Venus' atmosphere," study author Lina Hadid, a researcher at the Plasma Physics Laboratory (LPP) at the Centre National de la Recherche Scientifique (CNRS) in France, said in a statement.

Earth has a magnetic field that protects our atmosphere from being stripped away into space by the sun's solar wind. Venus has no such protection as a result of its internal core being cooler than ours, and therefore not being able to move as much and generate a magnetic field. It does possess a weak "induced magnetosphere", however, which is formed as a result of the charged solar wind slamming into the Venusian atmosphere and ionizing the atoms.

Venus's atmosphere is comprised of 96.5 percent carbon dioxide and 3.5 percent nitrogen, along with trace amounts of other gases like oxygen and sulfur dioxide. Despite being the second planet from the sun, Venus is the hottest planet in our solar system with a surface temperature of over 864 degrees Fahrenheit, due to the powerful greenhouse effect of its atmosphere, and also has an atmospheric pressure of 93 times that of Earth's.

BepiColombo passed through this weak magnetosphere for around 90 minutes in August 2021 as it adjusted its course en route to Mercury, and detected that charged carbon and oxygen ions appeared to be escaping the atmosphere.

Scientists still aren't sure exactly why this happens, but it may be because the solar wind hitting the atmosphere accelerated the ions to such a speed that they could escape the planet's gravity, pouring out into space.

"These are heavy ions that are usually slow moving, so we are still trying to understand the mechanisms that are at play. It may be that an electrostatic 'wind' is lifting them away from the planet, or they could be accelerated through centrifugal processes," Hadid said.

Venus is thought to have at one time been more like Earth, possessing liquid water on its surface many millions of years ago before its surface became so hot.

"Some researchers suggest the existence of habitable surface and oceans as late as around 700 million years ago. However, other researchers think Venus was always too warm for surface liquid water oceans to condense and may have looked like it does today for most of its geological history," Sara Seager, a professor of planetary science, physics and aerospace engineering at the Massachusetts Institute of Technology, told Newsweek.

Studying how the planet loses materials to space may help researchers understand how Venus became the inhospitable hellscape it is today.

"Characterizing the loss of heavy ions and understanding the escape mechanisms at Venus is crucial to understand how the planet's atmosphere has evolved and how it has lost all its water," Dominique Delcourt, a researcher at LPP and the principal investigator of BepiColombo's Mass Spectrum Analyzer instrument, said in the statement.

It is hoped that further missions will find out more details about Venus' atmosphere, magnetosphere, and surface, revealing the secrets of our planetary neighbor's past. In the next few years, ESA's Envision mission, NASA's VERITAS orbiter and DAVINCI probe, and India's Shukrayaan orbiter will be sent to Venus to gather more data.

"Recent results suggest that the atmospheric escape from Venus cannot fully explain the loss of its historical water content. This study is an important step to uncover the truth about the historical evolution of the Venusian atmosphere, and upcoming missions will help fill in many gaps," study author Moa Persson, a researcher at the Swedish Institute of Space Physics, said in the statement.

Do you have a tip on a science story that Newsweek should be covering? Do you have a question about Venus? Let us know via science@newsweek.com.

Uncommon Knowledge

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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.

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