At last week’s “Breakthrough Discuss” meeting in Berkeley, California, the focus was on the migration of life in the Universe and the search for extraterrestrial life and genomes. The annual conference, sponsored by the Breakthrough Initiatives organization, came only a day after the first pictures from a black hole were published, and the same day Israel’s Beresheet probe crashed on the Moon—a reminder that grandeur and failure sometimes go hand-in-hand when advancing high-risk space projects.
The meeting opened on an inspirational note, with music from Star Wars and a video message from the late Stephen Hawking. During the first session on the migration of life, the question loomed large whether panspermia, including the transport of life to Earth from outside the solar system, is possible. Most scientists in the panel discussion seemed to agree it was likely within the solar system, as has been proposed for Venus, Earth, and Mars. They were less enthusiastic about the spread of life from interstellar space, although Steinn Sigurdsson of Pennsylvania State University theorized that an object as extremely “fluffy” as Oumuamua could still deliver a load of microbial life to a planet with a significant atmosphere (such as Earth), because the microbes would slowly and relatively gently descend to the planet’s surface. He reasoned that encounters with interstellar objects may have happened 100 times in Earth’s history.