Is there life on Venus? American scientists ready space missions to explore the possibility

A group of scientists thinks they detected signs of life on Venus and America is intent on finding out the truth through a combination of public and private missions to Earth’s neighbor.

NASA is making plans for an uncrewed trek to Venus before the end of the decade to answer questions about life on other planets.

New attention to Venus was spurred on by a U.K.-led research team’s apparent discovery last year of phosphine gas in the planet’s atmosphere. Scientists used powerful telescopes to discover the gas.

On Earth, phosphine is associated with life. On Venus, scientists are trying to figure out if it is a sign of life.

In June, NASA selected two new missions: DAVINCI+, focused on Venus’ atmosphere, and VERITAS, focused on Venus’ surface. Tom Wagner, a NASA scientist who leads the Discovery Program that selected the missions, said the DAVINCI+ mission will measure phosphine.

“The potential phosphine discovery, or the possibility that phosphine was discovered in the atmosphere of Venus, that was like a lightning bolt through the community, right?” said Mr. Wagner. “Because there are questions like, ‘Hey, some people think that life could survive in the atmosphere of Venus even if it doesn’t survive on the surface.’ It’s a really intriguing question.”

Venus, the second planet from the sun and Earth’s neighbor, is the brightest natural object in Earth’s night sky other than the moon. But it has traditionally been Earth’s other neighbor, Mars, that captures the imagination and inspires tales of extraterrestrials.

The potential phosphine gas discovery on Venus provoked a vigorous debate on the possibility of life on the brightly lit and extremely hot planet. Some scientists argued that the U.K.-led scientists misinterpreted the data.

Sara Seager, an MIT planetary scientist who co-authored the U.K.-led research team’s study, said she is eager to examine more information but it was not just phosphine that was unexpectedly detected on Venus. She said there is other evidence of things in Venus’ atmosphere that do not make sense, including small amounts of molecular oxygen and the “tentative detection of ammonia NH3.”

“It’s like someone leaving these clues, you know?” Ms. Seager said. “Like a forensic crime scene, we’ve got a puzzle something together and you can’t just say, ‘Oh, that means there’s life.’ Cause it doesn’t, but it’s not just phosphine.”

Mr. Wagner said NASA’s team is considering making a subtle change to the instruments to measure trace amounts of phosphine in Venus’ atmosphere that it might otherwise miss.

NASA has said the DAVINCI+ and VERITAS missions, each costing $500 million, are both intended to study the “lost habitable” world of Venus.

According to NASA, Venus may have been the first habitable world in our solar system complete with an ocean and an Earth-like climate. Mr. Wagner said he expects NASA’s upcoming missions to rewrite the textbooks on Venus and serve as a rediscovery of the planet.

“It’s not just going there and measuring phosphine, it’s actually really going and understanding how the planet works as a system, if phosphine was there, how it was generated, and what other markers for life might be your precursors to life, and overall habitability questions — that’s what we’re really getting at,” Mr. Wagner said.

The DAVINCI+ and VERITAS missions will take approximately six months to get from Earth to Venus, according to NASA officials. Mr. Wagner said VERITAS will orbit Venus for at least a couple of years mapping the planet while DAVINCI+ will descend through the atmosphere in approximately 40 minutes. Once DAVINCI+ hits Venus’ surface, it will have approximately 10 minutes to take readings before succumbing to the planet’s surface temperature that can top 900 degrees Fahrenheit.

NASA’s focus on Venus is not fleeting. Both missions are expected to launch between 2028 and 2030, but NASA is already taking steps to make other trips to Venus possible. In June, NASA published a solicitation for partners to help develop “Hot Operating Temperature Technology” for Venus that Mr. Wagner said was about making electronics, batteries, and radios that can survive extreme heat.

The long-term outlook of NASA stands in stark contrast to the strategies of billionaires Jeff Bezos, who intends to visit outer space later this month, and Elon Musk, who has designs on colonizing Mars.

NASA’s careful plodding is part of the approach that has sustained the agency throughout its history and enabled it to exceed expectations.

“We use ‘habitability’ when it’s like, ‘OK, we’re not looking for a living thing moving around,’ right? We’re trying to understand maybe how life could have formed,” Mr. Wagner said. “Heck, if we see life, that’s great. But you know, if we don’t, it’s still another piece of the puzzle.”

If there is life on Venus, Ms. Seager said she thinks it would be associated with the planet’s cloud droplets and her team is working on a privately funded mission to examine the droplets. Her team is also working with Rocket Lab, a California-based company, that has made plans to hunt for life in Venus’ clouds in a mission scheduled for 2023.