Project Hail Mary

by Andy Weir

What’s the cube root of eight?” I take a deep breath and speak slowly. “Two times e to the two-i-pi.” “Incorrect. What’s the cube root of eight?” But I wasn’t incorrect. I just wanted to see how smart the computer was. Answer: not very. “Two,” I say. “Correct.”

Only three tubes remain: an IV in my arm, a tube up my butt, and a catheter. Those latter two are kind of the signature items I wanted removed, but okay.

My crotch hurts so bad I have to laugh. It’s just so absurd. Plus, the endorphins are kicking in and making me giddy. I look back at the catheter by my bunk.

It’s just a thin red line of—

SUBJECT: The Thin Red Line

My subconscious wants to tell me something. Seeing the line of blood must have reminded me of the “Thin Red Line” title of that email.

I ask myself: How far is it from L.A. to New York? My gut answer: 3,000 miles. A Canadian would have used kilometers. So I’m English or American. Or I’m from Liberia. I know Liberia uses imperial units but I don’t know my own name. That’s irritating.

“Eat.” Who am I to question a creepy robot-armed computer overlord? I cautiously lick the substance. Oh my God it’s good! It’s so good! It’s like thick gravy but not too rich. I squeeze more straight into my mouth and savor it. I swear it’s better than sex.

They say hunger is the greatest seasoning. When you’re starving, your brain rewards you handsomely for finally eating. Good job, it says, we get to not die for a while!

Instant toga. “Self-ambulation detected,” says the computer. “What’s your name?” “I am Emperor Comatose. Kneel before me.” “Incorrect.”

“Holy moly!” I say. “Holy moly”? Is that my go-to expression of surprise? I mean, it’s okay, I guess. I would have expected something a little less 1950s. What kind of weirdo am I?

What the fudge is going on?! Fudge? Seriously? Maybe I have young kids. Or I’m deeply religious.

0.348 seconds. Distance equals one-half acceleration times time squared. So acceleration equals two times distance over time squared. These formulas come easily to me. Second nature. I’m definitely skilled at physics. Good to know.

The gravity in this room is too high. It’s 15 meters per second per second when it should be 9.8. That’s why things falling “feel” wrong to me.

Cool thing about pendulums: The time it takes for one to swing forward and backward—the period—won’t change, no matter how wide it swings. If it’s got a lot of energy, it’ll swing farther and faster, but the period will still be the same. This is what mechanical clocks take advantage of to keep time. That period ends up being driven by two things, and two things only: the length of the pendulum and gravity.

“What’s your name?” the computer asks. I look down at my sheet toga. “I am the great philosopher Pendulus!”

Golly. Thing is, in a centrifuge, the farther you get from the center, the higher the centripetal force will be. So if I were in a centrifuge, the “gravity” down here would be higher than it was upstairs. And it isn’t. At least, not enough to get a different number of pendulum cycles.

How do I know all that space stuff? I just know it. It feels like second nature—information I use all the time. Maybe I’m an astronomer or a planetary scientist.

“The sun’s output will drop a full percent over the next nine years. In twenty years that figure will be five percent. This is bad. It’s really bad.” I stared at the graph. “That would mean an ice age. Like…right away. Instant ice age.”

It had been a heck of a year since the JAXA announcement about the Petrova problem. But study after study confirmed their findings. The clock was ticking and the world needed to find out what was going on. So Project ArcLight was born.

ArcLight was the most expensive unmanned spacecraft ever built. The world needed answers and didn’t have time to dillydally. Normally if you asked a space agency to send a probe to Venus in under a year, they’d laugh in your face. But it’s amazing what you can do with an unlimited budget. The United States, European Union, Russia, China, India, and Japan all helped cover costs.

“Venus moves very fast compared to Earth, which means more fuel just to catch up. Even under ideal conditions, it actually takes more fuel to get to Venus than it does to get to Mars.”

“Because the Petrova line is widest there—as wide as the whole planet. And we can use the planet’s gravity to help us out. ArcLight will actually orbit Venus twelve times while collecting samples of whatever material the Petrova line is made of.” “And what is that material, you think?” “We have no idea,”

Is this actually alien life? Am I really that lucky?! To be alive when humanity first discovers extraterrestrial life?! Wow! I mean—the Petrova problem is still terrifying but…wow! Aliens! This could be aliens! I couldn’t wait to talk about this with the kids tomorrow—

I like kids. Huh. Just a feeling. But I like them. They’re cool. They’re fun to hang out with. So I’m a single man in my thirties, who lives alone in a small apartment, I don’t have any kids, but I like kids a lot. I don’t like where this is going… A teacher! I’m a schoolteacher! I remember it now! Oh, thank God. I’m a teacher.

“Ryland Grace?” said a woman’s voice.

“ ‘An Analysis of Water-Based Assumptions and Recalibration of Expectations for Evolutionary Models.’ ” She looked up at me. “You wrote this paper, yes?”

“They’re wrong!” I crossed my arms. “There’s nothing magical about hydrogen and oxygen! They’re required for Earth life, sure. But another planet could have completely different conditions. All life needs is a chemical reaction that results in copies of the original catalyst. And you don’t need water for that!”

“So…when you say ‘a certain amount of authority’…” “I have all of the authority.” “You have an accent. Are you even from America?” “I’m Dutch.

“Scientists all over the world will be looking at them, but I want you to be the first.” “Why?” “It lives on or near the surface of the sun. Does that sound like a water-based life-form to you?” She was right. Water simply can’t exist at those temperatures. After about 3,000 degrees Celsius, the hydrogen and oxygen atoms can’t stay bound to each other anymore. The surface of the sun was 5,500 degrees Celsius.

“The field of speculative extraterrestrial biology is small—only five hundred or so people in the world. And everyone I talk to—from Oxford professors to Tokyo University researchers—seems to agree that you could have led it if you hadn’t suddenly left.” “Gosh,” I said. “I didn’t leave on good terms. I’m surprised they said such nice stuff about me.”

“Wait. The Russians, Canadians, and Americans all just do whatever you tell them?” “Yes. Without question.” “Are you joshing me with all this?!” “Get accommodated with your new lab, Dr. Grace. I have other things to deal with.”

And that velocity…it’s a lot of velocity. Yes, it’s going down, but wow! To reach Earth orbit you only need to go 8 kps. I’m going over 11,000. That’s faster than anything in the solar system. Anything that fast will escape the sun’s gravity and go flying off into interstellar space. The readout doesn’t have anything to indicate what direction I’m going. Just a relative velocity. So now my question is: Am I barreling toward the sun, or away from it?

But then I noticed they only emit light when they’re moving. And boy, do they emit a lot of it. I mean, not a lot from our point of view, but for a tiny single-celled organism it’s a ton.” “And how is that relevant?” “I did some back-of-the napkin math. And I’m pretty sure that light is how they move around.”

“Believe it or not, light has momentum,” I said. “It exerts a force. If you were out in space and you turned on a flashlight, you’d get a teeny, tiny amount of thrust from it.” “I didn’t know that.” “Now you do. And a teeny-tiny thrust on a teeny-tiny mass can be an effective form of propulsion. I measured the dots’ average mass at about twenty picograms. That took a long time, by the way, but that lab equipment is awesome. Anyway, the movement I see is consistent with the momentum of the emitted light.”

Nothing in nature has that kind of energy storage. You don’t understand how much energy these dots are emitting. It’s like…getting to the scales of mass conversion. E = mc2 kind of stuff. These tiny dots have more energy stored up in them than remotely makes sense.” “Well,” she said. “They did just come from the sun. And the sun is losing energy.” “Yeah. That’s why I think it’s a life-form,” I said. “It consumes energy, stores it in some way we don’t understand, then uses it for propulsion. That’s not a simple physical or chemical process. That’s complex and directed. Something that must have evolved.”

“People always assumed our first contact with alien life—if any existed—would be little green men in UFOs. We never considered the idea of a simple, unintelligent species.” “Yeah,” I said. “This isn’t Vulcans dropping by to say hi. This is…space algae.” “An invasive species. Like cane toads in Australia.”

This star I’m looking at…it’s not the sun. I’m in a different solar system.

Astrophage can propel itself with light and has absurd energy-storage capability. It’s had God-knows-how-many billion years of evolution to get good at it. Just like a horse is more energy efficient than a truck, Astrophage is more energy efficient than a spaceship.

I even put a few Astrophage in a radiation-containment vessel and exposed it to the gamma rays emitted by Cesium-137 (this lab has everything). I called it the “Bruce Banner Test.” Felt good about that name. Anyway, even gamma couldn’t penetrate the little bastards.

Back to the microscope. “Okay, you little reprobates. You’re radiation-proof, I’ll grant you that. But how about I stab you in the face?” Normally a nanosyringe would be controlled by finely tuned equipment. But I just wanted some stabby time and didn’t care about the tool’s integrity.

“How did you do it? What killed it?” “I penetrated the outer cell membrane with a nanosyringe.” “You poked it with a stick?” “No!” I said. “Well. Yes. But it was a scientific poke with a very scientific stick.” “It took you two days to think of poking it with a stick.” “You…be quiet.”

“Can we pick our own teams?” Trang asked excitedly. “No. That just leads to a bunch of drama. Because children are animals. Horrible, horrible animals.”

Besides, if I had a nickel for every time I wanted to smack a kid’s parents for not teaching them even the most basic things…well…I’d have enough nickels to put in a sock and smack those parents with it.

These kids were going to grow up in an idyllic world and be thrown into an apocalyptic nightmare. They were the generation that would experience the Sixth Extinction Event. I felt a cramp in the pit of my stomach. I was looking out at a room full of children. Happy children. And there was a good chance some of them would literally die of starvation.

“According to the Indian Space Research Organization, you guys get going up to 0.92 times the speed of light.” I pointed at them. “Didn’t know we could do that, did ya? Figure out your velocity? They used Doppler-shift analysis of the light you emit to work it out. And because of that, they also know you’re going both directions: to and from Venus.” I frowned. “But if you hit an atmosphere at that speed you should die. So why don’t you?”

Planets don’t just reflect light. They also emit it. Everything emits light. The temperature of the object defines the wavelength of light emitted. Planets are no exception. So maybe Astrophage looked for Venus’s IR signature. It wouldn’t be as bright as Mercury’s, but it would be distinct—a different “color.”

How else could I find out if it’s Venus?” Spectroscopy. Look for carbon dioxide. I raised an eyebrow as the idea came to me. When light hits gas molecules, the electrons get all worked up. Then they calm down and re-emit the energy as light. But the frequency of the photons they emit is very specific to the molecules involved. Astronomers used this for decades to know what gases are out there far, far away. That’s what spectroscopy is all about.

Good news: Astrophage were attracted to carbon dioxide’s spectral signature! Bad news: My three irreplaceable, 10-micron-wide Astrophage had launched off somewhere—maybe at velocities approaching the speed of light—and I had no idea where they went. “Craaaaaap.”

My experiment worked way better than I expected. They saw what they thought was Venus and beelined for it. When they hit the light filters, they couldn’t go any farther. They probably kept pushing until I turned off the light.