Project Hail Mary

The sun is dying, being feasted on by tiny lifeforms based on Venus. The phenomenon, the "astrophage," is not unique: every star within dozens of light-years of Sol is suffering the same malaise...except one: Tau Ceti. With Earth's habitability in danger in a matter of decades, the countries of the world unite to send a near-lightspeed ship, powered by the same tiny lifeforms, to Tau Ceti to…