Particle.news
Download on the App Store

Early Earth’s Atmosphere May Have Forged Sulfur Biomolecules Needed for Life

New PNAS experiments show sunlight on Archean‑like gases produced cysteine alongside other sulfur organics abiotically.

Overview

  • CU Boulder–led laboratory simulations illuminated mixtures of nitrogen, carbon dioxide, methane, and hydrogen sulfide, generating trace sulfur‑bearing organics without biology.
  • Using high‑sensitivity mass spectrometry, researchers identified cysteine, taurine, and coenzyme M in the resulting organic haze, with tentative signals for methionine and homocysteine.
  • Scaling lab yields to planetary levels, the team estimated atmospheric production equivalent to roughly 10^27 cells’ worth of cysteine across early Earth.
  • The study proposes that these compounds could have reached surface environments via rainfall and settling, potentially supplying prebiotic chemistry even if life arose in specialized niches.
  • Findings challenge assumptions about sulfur as a strict biosignature and follow prior work showing dimethyl sulfide can form abiotically, informing interpretation of JWST detections on exoplanets.