In a Q&A, UC Berkeley astronomer Gibor Basri reality-checks the recent sci-fi movie and talks about the chances of encountering life elsewhere in the galaxy.
In the sci-fi book and now movie Project Hail Mary, astronaut Ryland Grace, played by Ryan Gosling, encounters three different alien lifeforms in the vicinity of Earth. He joins forces with one of them, from the star 40 Eridani, to try to stop another, an alien microbe from Tau Ceti, that is eating stars — including our sun. The third lifeform saves the day.
Aliens have long been a common trope in science fiction, but for audiences not steeped in Star Trek and Star Wars or who may be skeptical that UFOs are alien spacecraft, this premise may seem far-fetched.
So we asked UC Berkeley astronomer Gibor Basri, who has conducted research on distant planets, how likely it is that life exists around two stars a relatively short distance from Earth, with one being an advanced technocivilization.
A long-time science fiction buff who liked the book and movie, Basri said one-celled life in the galaxy is not unlikely at all. If you make optimistic assumptions about the conditions required for simple life to arise, there may be hundreds of billions of habitable planets and moons in our galaxy where it could happen. In a recent perspective piece in the journal Nature Astronomy, Basri reviewed what’s known about the stars and planets with stable environments conducive to the origin of life — those in so-called Goldilocks zones — and speculated about the chances we will encounter other life within the Milky Way galaxy.
Basri, who taught in the astronomy department for 35 years, is best known as the discoverer of the first confirmed brown dwarf — dim but massive objects that are bigger than a planet but just shy of the mass needed to ignite nuclear fusion and become a star. Today, astronomers think that these failed stars may be as common as planets in the galaxy.
His specialty is star formation and the magnetic fields of stars — he authored the 2021 textbook An Introduction to Stellar Magnetic Activity — so he has opinions about the premises behind the Project Hail Mary book, by Andy Weir, and the movie, directed by Phil Lord and Christopher Miller. According to the plot, a microbe dubbed Astrophage is sucking up the energy from our sun and dimming it, which is destined to turn Earth into a frozen, dead planet. Basri also was a principal investigator for the Kepler mission to discover exoplanets a decade ago.
Suffice it to say, he has had a lot of time to think about habitable planets and the necessary requirements for life to arise — at least, life as we currently know it.