NASA’s pioneering Pioneer Venus mission.
Credit: NASA

Scientists diving back into decades-old data collected by NASA’s Pioneer Venus spacecraft mission have found evidence for phosophine in the clouds of Venus – considered a potential biosignature for life.

Pioneer Venus went into orbit around Venus in December 1978.  The spacecraft made a destructive plunge into the planet’s atmosphere on October 8, 1992.

Re-examine data

The recent ground-based data about phosphine in Venus’ clouds inspired researchers to re-examine data obtained from the Pioneer-Venus Large Probe Neutral Mass Spectrometer (LNMS) to search for evidence of phosphorus compounds.

The LNMS obtained masses of neutral gases (and their fragments) at different altitudes within Venus’ clouds.

Venus in ultraviolet taken by NASA’s Pioneer-Venus Orbiter in 1979 indicating that an unknown absorber is operating in the planet’s top cloud layer.
Credit: NASA

Habitable zone?

Published mass spectral data correspond to gases at altitudes of 50-60 km, or within the lower and middle clouds of Venus – which has been identified as a potential habitable zone.

“We find that LMNS data support the presence of phosphine; although, the origins of phosphine remain unknown,” the investigators report.

“We believe this to be an indication of chemistries not yet discovered, and/or chemistries potentially favorable for life. Looking ahead, and to better understand the potential for disequilibria in the clouds, we require a sustained approach for the exploration of Venus,” they write.

Go to their paper at:

Also, refer to this paper — Venus’ Spectral Signatures and the Potential for Life in the Clouds — led by Sanjay S. Limaye of the University of Wisconsin at:

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