Venus likely once had oceans made of carbon dioxide, according to researchers.
Venus is the planet most similarly compared to Earth because it's closest to Earth in size, mass, distance and chemical makeup.
Previous research suggested that Venus could have even had water like Earth, although it's much hotter and much more acidic. Instead, a team of scientists believe the planet was actually formed by oceans of carbon dioxide, reported Space.com.
"Presently, the atmosphere of Venus is mostly carbon dioxide, 96.5 percent by volume," lead study author Dima Bolmatov, a theoretical physicist at Cornell University in Ithaca, New York, said to Space.com.
The carbon dioxide present on Venus is different than the carbon dioxide exhaled by animals and used by plants in photosynthesis on Earth.
The carbon dioxide that we are used to dealing with every day can exist in three forms - solid, liquid or gas. On Venus, the carbon dioxide is existing in a fourth state of matter called a "supercritical" state, reported Space.com.
Supercritical fluids have properties of both a liquid and a gas - it could, for example, dissolve minerals like a liquid, while flowing like a gas.
The scientists researching the apparent carbon dioxide oceans on Venus looked at the supercritical carbon dioxide found on the planet.
They concluded that there could have been supercritical carbon dioxide present on the planet because Venus is currently more than 90 times that of Earth, but at one time Venus' surface pressure could have been dozens of times greater, reported Space.com.
"This in turn makes it plausible that geological features on Venus like rift valleys, riverlike beds, and plains are the fingerprints of near-surface activity of liquid-like supercritical carbon dioxide," Bolmatov told Space.com.
The scientists are continuing to study this supercritical form of matter found on Venus.
Their latest findings were published in the Journal of Physical Chemistry Letters.
