Clara Sousa-Silva is a quantum astrochemist at the Harvard-Smithsonian Center for Astrophysics. She investigates how molecules interact with light so that they can be detected on faraway worlds. Clara spends most of her time studying molecules that life can produce so that, one day, she can detect an alien biosphere. Her favorite molecular biosignature is phosphine: a terrifying gas associated with mostly unpleasant life. When she is not deciphering exoplanet atmospheres, Clara works hard to persuade the next generation of scientists to become an active part of the astronomical community.
David Grinspoon is an astrobiologist, award-winning science communicator, and prize-winning author. His research focuses on climate evolution on Earth-like planets, potential conditions for life elsewhere in the universe, and the planetary scale impacts of human activities on Earth. For the 2020-2021 academic year, he is Distinguished Visiting Scholar in the College of the Environment at Wesleyan University. He is a Senior Scientist at the Planetary Science Institute, Adjunct Professor of Astrophysical and Planetary Science at the University of Colorado, and Adjunct Professor of Science, Technology and International Affairs at Georgetown University. He is involved with several interplanetary spacecraft missions for NASA, the European Space Agency and the Japanese Space Agency. In 2013 he was appointed as the inaugural Chair of Astrobiology at the U.S. Library of Congress, where he studied the human impact on Earth systems and organized a public symposium on the Longevity of Human Civilization. He has given dozens of public lectures about climate change in the Solar System and has collaborated with numerous scholars from the humanities on the ethical, spiritual and political dimensions of space exploration.