This Is How Long You Could Run An Electric Car On The Astrophage From 'Project Hail Mary' If It Were Real

Phil Lord and Christopher Miller officially debuted their masterpiece, "Project Hail Mary", last week, an adaptation of Andy Weir's 2021 science fiction novel of the same name. I had read the book a few years ago, and really liked it, but the film is every bit a love letter to the visual medium. With practical effects, large-scale sets, incredible actors, and beautiful cinematography, this is one of those movies that will be remembered for generations. It's fun, powerful, emotional, and optimistic, all things that set it apart in the cinematic landscape of the mid-2020s. Seriously, if you haven't seen it, get your tickets for tonight. Or get a copy of the book. Or both.

Without wanting to give too much away, the main driving force of the plot (both in the book and the movie) is an extraterrestrial microorganism, eventually dubbed "astrophage", that is consuming the power of the sun and throwing Earth into a climate crisis that threatens to kill half of the global population. Rather than ignoring the climate crisis, like we are doing right now, the fictional governments of Earth in the book and movie band together to develop and execute a long-shot plan to figure out how to prevent an extinction-level event.

Because of the movie's popularity some people putting a little "powered by astrophage" decal on their car's fuel door or EV charging port, which got me thinking about how far a car could theoretically go on a tank full of this hypercharged interstellar powerhouse. This stuff is described as being super close to 100% efficiency, converting mass directly into energy with almost no conversion losses. Obviously it's fictional, but what if you could actually run a car on this stuff? Even better, the stuff actually consumes carbon dioxide, so it's actually carbon negative fuel! Forget renewables, forget fossil fuels, the future is astrophage, baby!

The movie doesn't dwell on the science quite as much as the book does, but the astrophage migrate through space converting heat energy from stars into pure mass with neutrinos, using that energy to travel by emitting massive amounts of infrared light, and breed in carbon-dioxide rich environments. In order to facilitate near-lightspeed space travel, the humans in the story harness the power of astrophage to not only make the plot possible, but to completely revolutionize the production of power and energy here on Earth. Once enriched with sun energy, the astrophage is incredibly power dense, significantly more so than nuclear. At one point in the book the main character, Ryland Grace, notes that just half a gram of astrophage could power New York City for a year.

That's a bit of a nebulous figure, but let's do a little research and math to break it down into a bit more consumable information. The U.S. Energy Information Administration indicates that New York City alone consumes about 1.4% of all electricity in the United States, so we know we're dealing with a big number. The EIA also tells us that over the course of a year The Big Apple will use around 60,000 gigawatt hours of electricity. 

This is a car blog, and we talk about cars, so I wanted to find a way to equate that somewhat arbitrary, possibly throw away line, into a figure that we could all wrap our heads around and understand a little bit. Some of the most efficient electric vehicles on sale right now are using just 22 kilowatt hours of electricity to go 100 miles. 60,000 gigawatt hours divided by 22 kilowatt hours is 2,727,272,730, multiply that by 100 and you get the total number of miles you could theoretically drive on the energy produced by half a gram of astrophage. A little over 272 billion miles. You would have to drive 75 million miles per day for ten years to come even close to this kind of consumption. 

Okay, so we know we definitely don't need half a gram of this stuff. For one thing, that kind of energy would be extremely unstable in a fender bender. If you accidentally T-boned an astrophage-powered car, it could spark a larger-than-nuclear-warhead explosion right there in the middle of the intersection. 

Re-reading back through the book last night, I finally found what I was looking for, a rough number that we can potentially use for this little experiment. A single cell of enriched astrophage produces about 1.5 million joules of energy, which is about 0.42 kilowatt hours of energy. Okay, I can work with that.

Let's say our efficient electric sedan carries an 80 kWh battery pack, and can travel 363 miles on a full charge. Each kilowatt hour of battery weighs about 17 pounds, so if we replace our big traction battery with a few cells of astrophage, the efficiency would likely rise by an appreciable amount, but we're going to ignore variables like that for this rudimentary experiment. To get 80 kWh worth of astrophage, we would need a grand total of 191 individual cells of the stuff, each weighing about 19 nanograms, according to the book. You there, fill it up with 3629 nanograms of high test astrophage, will you? For those keeping score, that's 0.000003629 of a gram. 

There would probably be some transmission losses and the electric motor certainly can't run on infrared light directly, so there's a conversion that each car would have to facilitate. But if we ever did theoretically convert to an entirely astrophage-based energy system here on Earth, cars would probably be one of the first things to be transferred over to this new tech. It would probably make most sense to replace electricity generation plants with new astrophage plants first, followed by intercontinental shipping and airplanes, but cars would come pretty soon after. And unlike gasoline, astrophage will gladly keep breeding and re-enriching itself for decades into the future. You'd never have to buy fuel again!

Who am I kidding? Humans would definitely try to figure out military applications first before any knock-on consumer benefits ever reached us regular folks.