Could NASA have unknowingly detected signs of potential extraterrestrial life on Venus back in 1978? A fresh analysis of Pioneer Venus data suggests exactly that.
In September 2020, astronomers stunned the world by detecting phosphine in Venus's upper atmosphere, where conditions mimic Earth's sea level. On Earth, this gas is primarily produced by anaerobic bacteria, sparking debate about possible microbial life.
Once dismissed as too hostile for life, Venus is now back in the spotlight, shifting focus from Mars. But was this finding truly groundbreaking, or did we miss clues decades ago?
Researchers led by Rakesh Mogul at California Polytechnic State University revisited NASA archives and pinpointed phosphine signatures in data from the Pioneer Venus Multiprobe (Pioneer 13) mission, which deployed a probe into Venus's clouds in December 1978.
The probe's Large Probe Neutral Mass Spectrometer (LNMS) sampled atmospheric gases during descent. Original analyses overlooked phosphorus compounds like phosphine, prioritizing others, as the instrument wasn't optimized for them.
This reanalysis confirms detection of a molecule matching phosphine's mass, at concentrations aligning with the 2020 study.
"I believe the evidence for these potential biosignatures was discounted because we assumed they couldn't exist in Venus's atmosphere," Mogul explains. The team also identified unexpected chemicals like chlorine, oxygen, and hydrogen peroxide.
"We need deeper, sustained exploration of Venus, akin to Mars efforts," the researchers urge. Missions are underway: Rocket Lab plans a 2023 probe to hunt for life signs by sampling clouds.
NASA's Discovery program finalists include the DAVINCI+ mission, mirroring Rocket Lab's approach. If selected, it could launch in 2026.
