Despite its Earth-like size and raw materials, Venus is extremely dry, meaning that water is almost completely lost to space. Planetary scientists at the University of Colorado Boulder and the University of Arizona Tucson Institute for Atmospheric and Space Physics used computer simulations to show that hydrogen atoms in the planet's atmosphere are blown off into space through a process known as dissociative recombination. , discovered to cause Venus. You will lose about twice as much water each day compared to previous estimates.
Today, Venus is dry because water is lost to space as atomic hydrogen. Image credit: Aurore Simonnet / Laboratory for Atmospheric and Space Physics / University of Colorado Boulder.
Despite being very close and similar in size and materials to Earth, Venus is extremely dry.
Research suggests that water from Venus' once-vapor-dominated atmosphere was lost to space through a mechanism called hydrodynamic outflow.
However, this mechanism cannot remove all the water needed to explain the current situation, and other escape mechanisms that have been studied are too slow to complete the water removal process.
“Water is really important for life,” says Dr. Erin Kangi, a researcher at the Atmospheric and Space Physics Laboratory at the University of Arizona, Tucson.
“We need to understand the conditions for liquid water to exist in the universe, which may have created the very dry conditions on Venus today.”
“Venus is definitely dry. If you took all the water on Earth and spread it around the planet like jam on toast, you'd have a layer of liquid about 3 kilometers (1.9 miles) deep. ”
“If you do the same thing on Venus, where all the water is trapped in the air, you'll only get 3 centimeters (1.2 inches), barely enough to get your toes wet.”
“Venus has 1/100,000 times less water than Earth, even though they are basically the same size and mass,” said Dr. Michael Chaffin, a researcher at the Institute for Atmospheric and Space Physics at the University of Arizona, Tucson. “Nevertheless,” he added.
The study authors propose a new explanation. It's a reaction called HCO+ dissociative recombination, and it releases more hydrogen than any previously suggested process.
HCO+ Dissociative recombination would nearly double the rate of water loss from Venus to space, resolving long-standing difficulties explaining the water abundance and isotope ratios measured on Venus.
Future Venus probe missions will need to measure HCO+ Abundance to determine whether it is HCO+ In fact, dissociative recombination is the primary mechanism of water loss.
“Our findings reveal new hints as to why Venus, which perhaps once looked almost identical to Earth, is almost unrecognizable today,” Dr. Changi said.
“We're trying to figure out what small changes occurred on each planet that drove them into these vastly different states.”
of result appear in the diary Nature.
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MS Chaffin other.Venus' water loss is dominated by HCO+ Dissociative recombination. Nature, published online on May 6, 2024. doi: 10.1038/s41586-024-07261-y
Source: www.sci.news
