Understanding the Evolution of Molecules in Space: Implications for Astrophysics, Astrochemistry, and Astrobiology

Abstract

The past 40 years have shown that, rather than hostile and barren, space is seething with dust, ices, and molecules evolving through time by a variety of intricate chemical processes. Combined theory, laboratory simulation, and observation show that organic molecules permeate the universe. Organics from space likely seeded the Earth after its formation 4.56 billion years ago and played a crucial role in the development of life as we know it. Such compounds likely fall on the surfaces of virtually all newly formed planets. This cosmic material is the final product of a complex cycle commencing with the outflow of matter from dying stars, proceeding through the diffuse interstellar medium, and into the dense molecular clouds where new stars and planetary systems form. The identities, abundances, distributions, and inter-relationships of these molecular building blocks of life remain largely unknown. Tracing this evolutionary path within our galaxy, and beyond, is an outstanding obligation of modern astrophysics. In this white paper we describe the systematic studies that must be made, and show that infrared spectroscopy from 2.5 to 40 μm is by far the most effective and efficient way to address this important enterprise. The required measurements are achievable using current technology, and can be executed by a medium-sized Astrophysics-class mission.