We are “the stuff of stars,” as connected to the cosmos as the Galaxy that spawned us. This stuff includes the light elements of hydrogen and helium that emerged from the Hot Big Bang some 14 billion years ago, along with the heavier elements of carbon, nitrogen, oxygen, and silicon that were forged in the bellies of giant stars, and the even heavier elements of iron, lead, cobalt, uranium, and other weighty isotopes that were created and dispersed by supernova explosions.
Thanks to the especially promiscuous ways of the carbon atom, interstellar space positively reeks with organic compounds. These include polycyclic aromatic hydrocarbons (PAHs), alcohols, sugars, and perhaps even amino acids. Water abounds – as vapors within star-forming clouds, as ices in pre-planetary disks, and in the flamboyant comets that have been found in orbit around nearby stars.
Artist’s rendering of the disk that surrounds the star Beta Pictoris. The disk is known to contain both exoplanets and exocomets. Image courtesy of Lynette Cook, the Far Ultraviolet Spectroscopic Explorer (FUSE), and NASA.
Within our own Solar System, we have found clear evidence for amino acids in the ...