Traces of phosphine gas was recently detected in the clouds of Venus, which suggests it could supports life – but a new study proposes the compounds may have originated from Earth.
Harvard researchers theorize that the biosignatures gas came to Venus from meteorites that grazed our planet’s atmosphere and crashed into the distant planet.
This notion was developed from a 2017 meteor that grazed Earth’s atmosphere over Australia for 90 seconds and then headed back on its journey to deep space.
The team believes this meteor could have collected up some 10,000 microbial colonies from our world and carried it to another.
The study notes that over the last 3.7 billion years, at least 600,000 space rocks that dipped into Earth’s atmosphere have a collided with Venus.
The 2017 meteor skimmed across Earth’s atmosphere for one and a half minutes at more than 35,000 miles per hour before returning to space.
Based on its trajectory as it skimmed the atmosphere, the team estimate that the rock was around 12 inches across and likely weighed at least 132 pounds.
‘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,’ the Harvard study reads.
‘As a result, the origin of possible Venusian life may be fundamentally indistinguishable from that of terrestrial life.’
Previous research determined that life is found up to an altitude of 43 miles from the surface.
Earth-grazing asteroids can dip 52 miles without experiencing significant heating – another lower would kill any life it gathered from our planet.
‘Further work is needed to investigate the existence and abundance of microbial life in the upper atmosphere,’ reads the study.
The team also notes that if a meteor coming from Earth enters the atmosphere of another planet, hitchhiking microbes could be released in clouds before the rock disintegrates in the atmosphere.
‘A future probe that could sample the habitable cloud deck of Venus will potentially enable the direct discovery of microbial life outside of Earth, the team wrote.’
‘Specifically, the capability to either directly analyze microbes in situ or to return an atmospheric sample to Earth will be critical in the design of a successful mission. Finding exactly the same genomic material and helicity on Venus and Earth would constitute a smoking gun for panspermia.’
On September 14, researchers announced Venus has traces of the biosignatures gas.
Astronomers at Wales’ Cardiff University and colleagues observed Venus using both the James Clerk Maxwell Telescope at Hawaii’s Mauna Kea Observatory and the Atacama Large Millimeter/submillimeter Array in Chile.
They detected a so-called spectral signature that is unique to phosphine — and furthermore were able to estimated that the gas is present in Venus’ clouds in an abundance of around 20 parts-per-billion.
The team explored assorted ways that the gas could have been produced in this setting — including from sources on the surface of the planet, micrometeorites, lightning, or chemical processes happening within the clouds themselves.
However, they were unable to determine exactly what is the source of the detected trace quantities of the gas.
The researchers have cautioned that the detection of phosphine is not itself robust evidence for alien microbial life — and only indicates that potentially unknown geological or chemical processes are occurring on the planet.
Further observations and modelling will be needed, they added, to better explore the origin of the gas in the planet’s atmosphere.