Earlier in September, researchers detected phosphine spots in the atmosphere of Venus — suggesting the presence of life — and since then scientists have surmised that a meteor may have scooped particles of Earth's atmosphere in the distant past and delivered them to our solar system's second planet, according to a new study shared on a pre-print server.
Possible life on Venus may come from Earth's atmosphere
The research comes from Harvard University's Department of Astronomy, and suggests asteroids may have grazed Earth's atmosphere in the distant past — at least 600,000 — and carried high-altitude microbes to Venus.
"Although the abundance of terrestrial life in the upper atmosphere is unknown, these planet-grazing shepherds could have potentially been capable of transferring microbial life between the atmospheres of Earth and Venus," wrote researchers Abraham Loeb and Amir Siraj in the study's abstract. "As a result, the origin of possible Venusian life may be fundamentally indistinguishable from that of terrestrial life."
Panspermia, or life origins from other planets
The idea of life transferring between planets via asteroids is called panspermia — the theory that life on one planet began from microorganisms moved from another one. In the recent past, scientists have suggested life on Earth may have begun this way.
Similar theories suggest life on Earth may come from comets and asteroids throughout the universe, reports Fox News. Previous studies have also considered the idea of panspermia, including one published this year — which suggested comets as an origin for and carrier of the "essential element" for life as we know it.
In 2019, NASA discovered sugar molecules on two separate meteorites — lending precedence to the idea of asteroids playing a critical role in giving birth to life on planets.
Possible life on Venus
As with the initial indication of possible life on Venus, this recent study is still awaiting peer review, so caution is advised before jumping to conclusions. In the earlier paper, researchers said the detection of possible life on Venus "is not robust evidence for life, only for anomalous and unexplained chemistry," emphasizing the need for additional work to confirm.
While researchers work to verify the presence of alien life in Venus' atmosphere, it's important to note how this biosignature may not be native to our sister planet. In fact, even if life on Venus arose from meteors skirting our atmosphere, the same might be said of life on Earth.