A story about an alien invasion typically revolves around diplomacy, military strategy, technological one-upmanship, and brinksmanship. But the invaders in Andy Weir’s Project Hail Mary are anything but typical.
Rather than a scheming sentient enemy, Weir gives us Astrophage, an opponent who is mindless—and microscopic. Astrophage, which is similar in its biology to a mold, lives on—and taps energy from—the surface of stars.
“It’s not intelligent in any way. It doesn’t care about us. But it gets to the point where there is so much of it on our sun that the sun is starting to lose luminance—it’s getting dimmer. And a four or five percent dimming of the sun would be fatal to life on Earth,” says Weir, who was a guest on New Books in Science Fiction in 2014 to talk about his runaway bestseller The Martian.
An unlikely antagonist deserves an unlikely hero. Enter Ryland Grace, a middle school science teacher, who long ago authored a scientific paper that declared water isn’t a prerequisite for life. This once-ridiculed thesis draws the attention of the woman mustering the worldwide response to Astrophage. Eventually, Ryland finds himself waking from a years-long coma without remembering how or why he got there 12 light years from Earth, where he must figure out how to cure our sun of its infection.
While Astrophage is a deadly invader, another extraterrestrial plays a collaborative role. Thanks to the friendship that emerges between Ryland and Rocky, a hard-shelled, spider-like sentient creature with blood of mercury who breathes ammonia and hails from a planet with 29 times the atmospheric pressure of Earth, Project Hail Mary is as much a story about cross-cultural and cross-species exchange as it is a story of science, problem-solving and heroism.