Can comets deliver prebiotic molecules to rocky exoplanets?
Published version
Peer-reviewed
Repository URI
Repository DOI
Change log
Authors
Abstract
jats:pIn this work, we consider the potential of cometary impacts to deliver complex organic molecules and the prebiotic building blocks required for life to rocky exoplanets. Numerical experiments have demonstrated that for these molecules to survive, impacts at very low velocities are required. This work shows that for comets scattered from beyond the snow-line into the habitable zone, the minimum impact velocity is always lower for planets orbiting Solar-type stars than M-dwarfs. Using both an analytical model and numerical N-body simulations, we show that the lowest velocity impacts occur onto planets in tightly packed planetary systems around high-mass (i.e. Solar-mass) stars, enabling the intact delivery of complex organic molecules. Impacts onto planets around low-mass stars are found to be very sensitive to the planetary architecture, with the survival of complex prebiotic molecules potentially impossible in loosely packed systems. Rocky planets around M-dwarfs also suffer significantly more high velocity impacts, potentially posing unique challenges for life on these planets. In the scenario that cometary delivery is important for the origins of life, this study predicts the presence of biosignatures will be correlated with (i) decreasing planetary mass (i.e. escape velocity), (ii) increasing stellar-mass and (iii) decreasing planetary separation (i.e. exoplanets in tightly-packed systems).</jats:p>
Description
Peer reviewed: True
Publication status: Published
Funder: Science and Technology Facilities Council (STFC) PhD Studentship
Keywords
Journal Title
Conference Name
Journal ISSN
1471-2946
Volume Title
Publisher
Publisher DOI
Sponsorship
Royal Society (URF\R1\211421)