What does the amino acid found in the atmosphere of Venus mean?

Question

An amino acid is a part of DNA, but it has only been found on Earth. Is the amino acid maybe from one of the space vehicles that has orbited, scanned, or surveyed Venus? How can a part of DNA survive in the dense, sulfuric acid-filled atmosphere? Scientist's haven't been able to determine what organism it's from, but it hasn't been brought to Earth yet. Could this be from the water that covered most of Venus billions of years ago? Did some type of life start to evolve before all the water evaporated? I'm kinda new to this site and have always wondered about this, so thanks to anyone who has an answer!

Answer 1

An amino acid is any acid that has an amine in it. They are not necessarily found in proteins. They can be found in conditions similar to deep space, for example:

In a laboratory at NASA Ames Research Center in California’s Silicon Valley, the team of astrobiologists shone ultraviolet light on deep-space-like "ices," simulating conditions that are commonplace in interstellar space. Deep-space ice is common water ice laced with simple molecules. The team subsequently discovered amino acids, molecules present in, and essential for, life on Earth.

Amino acids are really simple molecules, that could arise from a number of abiotic reactions. Do not be impressed if they are found on a barren planet, for they have been found in meteorites before:

Murchison contains common amino acids such as glycine, alanine, and glutamic acid as well as unusual ones such as isovaline and pseudoleucine. A complex mixture of alkanes was isolated as well, similar to that found in the Miller–Urey experiment. Serine and threonine, usually considered to be earthly contaminants, were conspicuously absent in the samples. A specific family of amino acids called diamino acids was identified in the Murchison meteorite as well.

I'll personally only be impressed when at least a protein or sequence of DNA/RNA is found outside Earth. Then we can speculate about life out there. I do believe it exists - I just think we are getting too excited now with stuff that may not necessarily be biotic.

Answer 2

People got very stirred up a few months ago about claims of a very clear (fifteen sigma) signature of phosphine in Venus's atmosphere. Other scientists reexamined those authors claims and found that that their very clear signature was clear as mud; that their evidence did not even pass the two sigma threshold, let alone a fifteen sigma threshold. (Two sigma is good enough for the social sciences. Five sigma is good enough for the physical sciences. Fifteen sigma essentially means nobody can reject this.) We do not yet know which is correct, the claims or counterclaims. What it does mean is that more investigation is needed.

The claims of the discovery of signatures of glycine in Venus's atmosphere has not yet been published in a peer-reviewed scientific journal. It has only been pre-published on the arXiv, Detection of simplest amino acid glycine in the atmosphere of the Venus. Pre-publishing on the arXiv is a very low bar. Passing peer review (which this article has not yet done) is where science starts. Passing peer review does not mean the evidence is solid. It means that some scientists think the claims in the article they reviewed appear to be plausible.

It will be time to get excited if the claims of the discoveries of phosphine and glycine do turn out to be true. But for now, the best thing to do is to wait for science to follow its slow methodical business.