Possibility of microbial life on Venus

US2 wrote: »

They found the chemical Phosphine in the atmosphere of Venus.

AMKC wrote: »

There is nothing on BBC 4 tomorrow about The Sky at Night. I just looked.

Deleted User wrote: »

That last question kinda threw them. They don't know what biological process produces phosphine on earth.

Deleted User wrote: »

Does anyone have a link to the press conference?

Deleted User wrote: »

No, the question before that asking if they knew what produces the gas on Earth. They couldn't definitively answer, but one (Sarah?) said that she was sure (without proof) the gas is produced biologically on Earth.

Despite a large body of robust circumstantial evidence for the production of
phosphine by life, the exact mechanisms for biologically-associated
production of PH3 are still debated, and the metabolic pathway leading to PH3
production in anaerobic bacteria is unknown. However, we note that the
absence of a known enzymatic mechanism is not evidence for the absence of
biological production. The synthetic pathways for most of life’s natural
products are not known, and yet their origin is widely accepted to be biological
{page break}
because of the implausibility of their abiotic synthesis, their obligate
association with life, and their chemical similarity to other biological products.
For example, a recently published, manually curated, database of natural
molecules produced by life on Earth contains ~220,000 unique molecules of
biological origin, produced by thousands of species (Petkowski et al. 2019a)
while the number of known, experimentally elucidated, metabolic pathways
from organisms belonging to all three domains of life is only ~2,720 (Caspi et
al. 2017). Further examples of the complexities in discovering metabolic
pathways for molecules associated with biological activity are provided in
Appendix E.