What you need to know:
- The head of NASA hailed the discovery as "the most significant development yet" in the hunt for extraterrestrial life.
Scientists have detected a gas called "phosphine" in the toxic atmosphere of Venus, which on Earth could originate from presence of life.
In an article published Monday in Nature Astronomy, a group of scientists said they used telescopes in the US state of Hawaii and Chile's Atacama Desert to observe Venus' upper cloud deck, around 60 km from the surface, and traced the apparent presence of phosphine gas.
The head of NASA hailed the discovery as "the most significant development yet" in the hunt for extraterrestrial life.
"PH3 (phosphine) could originate from unknown photochemistry or geochemistry, or, by analogy with biological production of PH3 on Earth, from the presence of life," said the article titled "Phosphine gas in the cloud decks of Venus".
Noting the detection of phosphine is not robust evidence for life, the scientists said that "there are substantial conceptual problems for the idea of life in Venus's clouds -- the environment is extremely dehydrating as well as hyperacidic."
Mars, a planet known to have once had all necessary ingredients for carbon-based organisms, has been a longtime target of human beings to find extraterrestrial life.
"Life on Venus? The discovery of phosphine, a byproduct of anaerobic biology, is the most significant development yet in building the case for life off Earth," NASA administrator Jim Bridenstine tweeted Monday.
"It's time to prioritise Venus."