Here is a problem that has been quietly gnawing at astronomers for decades.

The standard approach to detecting #life on other worlds involves scanning #exoplanet #atmospheres for #oxygen, #methane, and #ozone, whose presence is difficult to explain without #biology.

It's a clever idea, but it carries a hidden flaw. That entire shopping list was written by studying Earth. It is, inevitably, a search for life like us.

The list of ways that #chemistry alone can accidentally mimic these #biosignature gases is growing faster than the list of new ways to detect life.

Each new false positive scenario demands even more information about the #planet to rule it out, and there is a genuine question about whether that information can ever be gathered exhaustively.

But there is a solution.

#Assembly theory doesn't ask what #molecules are present in an #atmosphere. Instead, it asks how hard they were to make.

Every molecule can be assigned an assembly index, a minimum number of construction steps required to build it from basic #chemical building blocks.

Simple molecules are easy to assemble by chance, but truly complex ones, requiring many sequential steps, don't arise without something doing a great deal of deliberate selection.

That something would then be life itself.

#astrobiology #astronomy
https://phys.org/news/2026-03-life.html

Paper by Walker et al. (2026): https://arxiv.org/abs/2603.11086

#KnowledgeByte: An #Alien #Biosignature is any observable feature—such as a substance, pattern, or phenomenon—that provides scientific evidence of past or present life beyond Earth.

Scientists look for these "fingerprints of life" in the atmospheres and on the surfaces of planets and moons.

https://knowledgezone.co.in/posts/Alien-Biosignature-69b9060ffa60ffdd1b7b92e7

3I/ATLAS: ALMA Detects Most Enriched Concentration Of Methanol And Hydrogen Cyanide Observed In Any Comet Ever

https://fed.brid.gy/r/https://in.mashable.com/science/103046/3iatlas-alma-detects-most-enriched-concentration-of-methanol-and-hydrogen-cyanide-observed-in-any-co

Scoperte possibili grotte carsiche su Marte: nuovi indizi sulla presenza passata di acqua e vita

https://fed.brid.gy/r/https://www.galaxyaddicted.it/2025/11/grotte-carsiche-marte-hebrus-valles/

#Phosphorus Prepared #Earth For Complex #Life And Could Be A Valuable #Biosignature

https://www.universetoday.com/articles/phosphorus-prepared-earth-for-complex-life-and-could-be-a-valuable-biosignature

"A potential biosignature, which is how the Sapphire Canyon finding is described, is a substance or structure that might have a biological origin but requires more data or further study before scientists can make a conclusion about the absence or presence of life."

https://theconversation.com/scientists-detected-a-potential-biosignature-on-mars-an-astrobiologist-explains-what-these-traces-of-life-are-and-how-researchers-figure-out-their-source-265157

#Mars #Biosignature #Life #Chemistry #Evidence #Biology

*Fossilized Martian living bug slime. Maybe. #biosignature

https://www.nature.com/articles/s41586-025-09413-0