[EvaH (OP)]

Elena wonders...

I wonder, if indeed the phosphine found on Venus is from bacterial origin, how likely - if at all- could it be due to an "inoculation" of the Venus' atmosphere by the soviet missions to Venus. Assuming that some bacteria were picked up in the Earth's atmosphere, survived the trip and thrived and multiplied on Venus...would they be enough to produce the amount of phosphine, which was observed?

What do you think?

[evan_au]

A space probe smashing into the atmosphere of Venus at high speed would effectively sterilize the outside of the spacecraft.
- A spacecraft landing on the surface of Venus (which is hot enough to melt lead) would also sterilize the spacecraft from any Earth microbes.

The atmosphere of Venus is radically different from environments found on Earth. So it is highly unlikely that Earth microbes gently injected into any part of the atmosphere of Venus would last very long.