The Origin of Rocky Planets and their Atmospheres: A Rhapsody in Infrared

The chemical composition of the Earth and the inner solar system is very different than the primordial matter that formed the Sun and the giant planets. We still do not know if this pattern is generally reproduced among rocky exoplanets, but there are plenty of reasons to think that it does. Such differences are linked to events happening during, and soon after, the formation of any planetary system. For instance, because of the high volatility of the molecular carriers of carbon, nitrogen, and oxygen, the Earth formed relatively dry, with a greatly depleted complement of organics. Yet, some volatiles - enough to form the atmosphere and biosphere of present-day Earth - were ultimately delivered. With the recent launch of JWST, we are now in a new era of investigations into the fundamental question: How are water and organics delivered to rocky planets? To address this question, JWST enables sensitive molecular spectroscopy revealing the evolutionary pathway of water and organics from the interstellar medium, and all the way to the inner regions of planet-forming disks. I will review the history of molecular infrared spectroscopy of star- and planet forming matter, discuss new JWST observations, and dream about the future of infrared observatories.