New experiments simulating the surface of Saturn’s icy moon Enceladus suggest that organic compounds found in plumes emanating from its subsurface ocean may form on the moon’s surface, rather than within the sea itself. Further analysis showed these plumes were coming from rows of cracks on the moon’s surface that scientists compared to tiger stripes. To best approximate Enceladus’ surface ice, the team made ice with a mixture of water, methane, carbon dioxide, and ammonia. In organic life forms, amino acids make up the peptide chains in proteins that drive metabolic reactions, repair damaged cells, and transport nutrients, making them critical for life. “Molecules considered prebiotic could plausibly form in situ through radiation processing, rather than necessarily originating from the subsurface ocean,” Richards explained.