By Prasad Ganti

Project Hail Mary is a sci-fi book written by Andy Weir, the same author who earlier wrote “The Martian”. Both the book and the movie “The Martian” were successful. It is the same case for “Project Hail Mary”. I saw the movie, read the book, and saw the movie again. The movie has good visuals while the book has a lot of scientific details. I also marked both the fictional and real parts.

The plot is as follows. The Astrophage are a fictitious organism infecting a few stars in the neighborhood, including our own sun. The Astrophage draw energy from the sun and store it as increased mass. Einstein’s equation E=mc² gives the relationship between mass and energy (and the speed of light, which is a constant). This causes our sun to dim and thereby produces global cooling.

The Astrophage are attracted to Venus due to the presence of carbon dioxide in its atmosphere. They make a beeline to Venus to breed. They use the energy stored in the form of mass to travel to Venus, breed, and make the return trip to suck more energy out of the sun. This completes the cycle of converting energy to mass and then back to energy.

The continuous line of Astrophage from the sun to Venus results in the Petrova line, which is fictitious. This is how humans detect the first signs of the Astrophage. The Astrophage has infected other stars like Tau Ceti and 40 Eridani. Both these stars are real and are often used in other sci-fi works. However, Tau Ceti is unaffected by Astrophage. Humans want to find out why and plan a mission to Tau Ceti, which is about twelve light years away. The idea is to make use of the same method Tau Ceti is using to overcome the Astrophage. This mission is labelled “Project Hail Mary”.

Ironically, the spaceship is propelled by Astrophage. Astrophage is very efficient at storing and releasing large amounts of energy. Large amounts of Astrophage are bred on the earth to fuel the mission.

The mission has three astronauts, including Dr. Ryland Grace, who is a scientist. All three astronauts are put into a medically induced coma since the journey takes about thirteen years. To survive the medically induced coma, the astronauts are checked for a genetic mutation which is favorable. This is a fictitious concept. When Grace wakes up from his coma, he finds the other two astronauts dead. Slowly his memory comes back to him regarding why he is on this mission.

Grace sees another spaceship coming closer and flying parallel to his at the same speed. This continues for some time. The alien ship tries to send a message via a cylinder, which Grace retrieves. Eventually, an alien emerges from the ship via a constructed tunnel between the two ships. Each side of the tunnel has an environment conducive to their respective planets. There is a strong wall in between as a separator. The tunnel itself and the alien spaceship are built from Xenonite, a supposedly strong fictitious material.

The alien looks nothing like a human. It is more like a shelled organism with five limbs consisting of three fingers each. Two of the limbs are used like hands while the other three are used for standing and stabilizing. This alien is from the planet Erid, which circles the host star 41 Eridani. While the host star itself is real, the planet Erid is fictitious, including its characteristics. Grace calls the alien “Rocky” due to his hard, stone-like appearance, but he is nevertheless intelligent, with amazing engineering skills.

Erid’s magnetic field is 25 times stronger than Earth’s. Its atmosphere is 29 times thicker. It provides radiation protection for its citizens. Eridians cannot “see” because their planet is very dark and devoid of any radiation, but their sense of echolocation is very strong, causing them to “see” like a sonar does on earth. As a result, Eridians are extremely susceptible to radiation. Eridians are a combination of organic material as well as inorganic ones like oxidized minerals, metallic alloys, etc. Liquid mercury is their blood. They breathe ammonia. While the environment and the beings are a work of fiction, it gives us an idea that life need not be in the form of what we see around us.

Eridians communicate using sounds. They have multiple vocal cords, producing multiple frequencies at once. Grace learns the basic words by analyzing the waveforms produced. Fourier transforms come to the rescue by breaking down the sounds into their constituent frequencies. This is a real mathematical concept. Grace writes some software to convert Rocky’s sounds into speech he understands. Then he communicates the basic concepts using “show and tell”. Grace provides a human word while Rocky comes up with an equivalent Eridian word.

Together, Grace and Rocky set themselves to solve the Astrophage problem. They find that as they get closer to Tau Ceti, there is a Petrova line going from the star to its planet called Adrian. While Tau Ceti is real, Adrian is fictitious. They retrieve a sample of Adrian’s atmosphere. They find an organism which is labelled “Taumoeba” (presumably for amoeba from Tau Ceti), which is capable of eating Astrophage. They breed Taumoeba.

Grace sends the Taumoeba in a miniature spaceship, along with information on what he found and how the Astrophage could be defeated, back to the earth. The four miniature spaceships travel faster than his spaceship back to the earth. Earthlings use the cargo to solve their Astrophage problem. What is amazing about this story is the cooperation between the human and the alien. Usually stories thrive on conflict, but this is different.

I omitted a lot of detail, including the ending. Happy reading! Happy viewing! With this book, Andy Weir, in my opinion, enters the pantheon of sci-fi writers like Isaac Asimov, Arthur C. Clarke, and Frank Herbert.