David Catling is an astrobiologist and planetary scientist who studies what characteristics of Earth help it support life, and whether what we think of as life might be found on other planets. To this end, he looks at the ways that planetary surfaces and atmospheres develop together, and how life on Earth co-evolved with Earth's atmosphere. His work spans both a variety of disciplines (astronomy, biology, geology) and planets (Earth, Mars, Venus and exoplanets). In addition to his extensive scholarly work, he is the author of Astrobiology: A Very Short Introduction, published by Oxford University Press.