Institute of Astronomy

Exploring the Origin of Carbon in Terrestrial Worlds

SpeakerTalk DateTalk Series
Edwin Bergin31 July 2014Across HR 2014 Talks


Given the central role of carbon in the chemistry of life, it is a fundamental question as to how carbon is supplied to the Earth, in what form and when. In this talk I will outline our knowledge about carbon in the Earth and discuss the potential reservoirs available to supply needed carbon to a young-forming planet. An important conundrum lies in the fact that nearly half of the carbon in the interstellar medium is found in some refractory solid state and yet the Earth's surface (and primitive undifferentiated meteorites) are significantly carbon-poor relative to silicon. This problem extends beyond our Solar System as metals in the atmospheres of white dwarfs are suggested to be a result of accretion of asteroids, and these systems often display a marked carbon deficiency. We suggest that chemical kinetics plays a key role in accounting for this carbon deficiency. We will outline models that explore the destruction of carbon grains in the disk and explore the evolution of the molecular carbon reservoir that precedes planet formation. Where possible I will outline the astrophysical observations that can set limits on the potential distribution and evolution of these reservoirs in protoplanetary disks.