How scientifically accurate is the Hail Mary Project?

The highly anticipated science fiction film Hail Mary Project was released in theaters today. In it, light-eating alien microbes sap the sun’s energy, threatening life on Earth with extinction. To find a solution, an unlikely hero – a college professor played by Ryan Gosling – is sent on a one-way mission to star Tau Ceti and meets a sidekick nicknamed Rocky along the way.

The premise is fantastic, but the concepts that inspired the story are real and not as implausible as you might think.

Andy Weir, author of the eponymous book that inspired the film, carefully studied the physics, astronomy, and biology that drive the plot, and he even consulted on set to maintain scientific accuracy while the actors improvised during scenes.

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“The actors are an integral part of the creative process, [but] Sometimes the science on what they’re saying would be wrong,” Weir says. “And so I would go to the directors, and then they would say, ‘Oh, okay, well let’s try it again, but this time let’s say nanograms instead of milligrams.'”

With this in mind, Scientific American spoke with Weir, as well as an astrobiologist, a physicist, and a few astronauts, about the real-life science that inspired this work of cinematic fiction.

How does the film’s “Astphage” work?

The premise of the film is that alien microbes called Astrophage (roughly translated from ancient Greek as “star eater”) colonize the sun and travel between our star and Venus to reproduce. As the star-clutching Astrophage population increases, it dims sunlight, endangering life on Earth.

Microbes could travel from Sun to Venus and back with the right amount of energy, but the trip would require different amounts in each direction, says Chad Orzel, a physicist at Union College. “From Sun to Venus would not be so difficult because there is already a constant flow of [solar] “The particles are going in that direction,” he says, but going back “would require a little more effort” to counteract the solar wind.

The way Weir solved this problem, he says, was to imagine Astrophage as capable of absorbing neutrinos, so-called ghost particles that don’t tend to interact with other matter. A neutrino can, for example, pass untouched through a light-year of lead, and every second, tens of billions of them pass through every cubic centimeter of the Earth – and through you, dear reader. Most of these neutrinos come from the Sun, which constantly emits them when it shines. But these ghost particles TO DO transport mass (and therefore energy via Albert Einstein’s practical equation E = MC²). If Astrophage could use the sun’s energy to create neutrinos in their cell membranes (“science” becomes very hand wavy here), Weir mused, maybe they could use the particles as a propellant. Astrophashing could convert most of the neutrino mass back into energy (or, indeed, infrared light) which they would then scatter directionally to produce thrust.

This (imaginary) process would be effective and powerful. In the film, the Astrophages constitute the fuel that powers the Hail Mary, the ship that takes Gosling’s character to Tau Ceti.

“The idea exists,” says Orzel. ” If you want completely convert matter into energy, the usual way to do this is to combine it with an equal amount of antimatter. [But] there just isn’t a lot of antimatter going around.

Are Tau Ceti, 40 Eridani and the planet Adrian real places in the universe?

Yes, these places actually exist, even if Adrian is a fictitious name. Tau Ceti is a star located about 12 light-years from Earth, and 40 Eridani, the astropagus-prone star system from which Rocky hails, is about 16 light-years from Earth. Adrian, the Tau Ceti world that the characters visit, really exists in astronomers’ catalogs of exoplanets like Tau Ceti e (although we know very little about it).

Overall, these places are not that far from each other. According to Weir, the use of stars close and similar to ours in the story was an intentional choice.

In the Hail Mary Project In the universe, all life in the Milky Way sector of our solar system comes from an ancient Astrophage ancestor that radiated long ago from Tau Ceti, Weir says. “Since all life in history is distantly related,” he says, “I wanted everything to take place around similar stars, because similar stars end up with similar elements available on the planets.”

Just like much of life on Earth, Astrophages have cellular organelles called mitochondriawhich would be consistent with the idea that terrestrial life and Astrophage share a common ancestor, notes astrobiologist Mike Wong of Carnegie Science. We know that mitochondria evolved on Earthhowever, he adds.

“There are many life forms on Earth that do not have mitochondria, such as bacteria and archaea,” he says. “If there were an origin for life in the larger cosmic neighborhood, it would seem that Earth would have to be the origin.”

Artificial gravity plays an important role in this film. Are we close to achieving this?

Artificial gravity can exist in theory and could work much like it does on the Hail Mary. Part of a spacecraft could rotate in a circle and the resulting centripetal force could simulate gravity for the passengers inside.

Drew Feustel, senior astronaut of the private space station company Vast and one of the film’s technical consultants, says building a rotating habitat is not only possible but also on Vast’s next priority list. But he points out that there is no known way to simulate gravity on earth (which happens at one point in the film).

Gosling’s character, a college professor, trains to become an astronaut in a short period of time. Is this realistic?

NASA, or any other public space agency, is not in the business of sending just anyone into space. But there’s always been a sliding scale of expertise, says former NASA astronaut Mike Massimino.

Between 1983 and 2003, NASA trained “payload specialists” to fly as Space Shuttle crew members with specialized, mission-critical knowledge. And, it is famous, a professor was really selected to go into space. But overall, payload specialists received less training than full-time astronauts. “Of course it was a huge difference in what you could do,” says Massimino.

A quick look at NASA’s astronaut corps past and present shows that its members have a wide variety of backgrounds, from teaching to engineering to flying to planetary science. What an astronaut needs to know depends on the mission and the skills other crew members have, Massimino says.

At a minimum, “what you need to be able to do is prepare a meal, use the restroom, and know all emergency procedures.”

When Gosling’s character finds himself stranded in space without his crew, the gaps in his knowledge become apparent. But the film does a remarkably realistic job of showing how even the basics can be difficult to understand at first and perhaps even pokes fun at romanticized space films.

“It’s very unglamorous,” Feustel says of space travel. “This is reality.”