Project Hail Mary - Mapping the Astrophage

Navigating the Stars of Project Hail Mary

Warning: may contain spoilers for Project Hail Mary

One of the joys of Andy Weir’s Project Hail Mary is how convincingly it blends speculative science fiction with real astronomy. Val Hovey’s interactive Project Hail Mary – Stellar Navigation Chart leans into that realism, using authentic data from the GAIA DR3 star survey to recreate the ship’s onboard navigation map used in the film of the book.

The result is a beautifully atmospheric 3D map of our local stellar neighborhood that allows users to explore nearby stars exactly as Ryland Grace might aboard the Hail Mary. By plotting the real spatial relationships between nearby systems, the map also helps us visualize Grace’s journey from Earth to Tau Ceti and better understand the significance of the novel’s mysterious ‘Petrova Line’

The map uses data from the European Space Agency’s Gaia mission, which has measured the positions, distances and properties of more than 1.8 billion stars in the Milky Way. This gives the visualization a remarkable sense of realism. Familiar nearby stars such as Sirius, Tau Ceti and Wolf 359 appear in their correct relative positions around our own Solar System.

As you explore the map, you’ll notice a system of three stacked reference planes (a skybox). These parallel grids form a simplified 3D coordinate system: the middle plane aligns with the Sun, while the upper and lower grids anchor stars sitting above or below the local galactic plane. When you switch to the ‘galactic’ view, the map makes this 3D structure even clearer by dropping straight vertical projection lines from other stars directly down (or up) to the Sun's plane.

Tapping the map’s 'Color' button activates a view based on the GAIA DR3 survey, which measured the spectra and colors of over 1.8 billion stars in our galactic neighborhood. This feature renders stars in their approximate true stellar colors - cooler red dwarfs emit a distinct orange-red glow, while blazing, hotter stars shine brilliant white or blue-white."

Fans of Project Hail Mary will likely spend most of their time exploring the 'Petrova' view, which overlays the novel’s fictional astrophage infection onto the real stellar map. Named after the 'Petrova line' - one of the key astronomical clues in the story - this visualization highlights the inferred path of the infection as it leaps between nearby stars.