Theoretically, any star infected with Astrophage should have one, right? The little blighters need carbon dioxide to breed. Can’t get that from the star (unless you go way into the core, and I don’t know if even Astrophage could survive those temperatures).

If I see a Petrova line, it means that Tau Ceti has an active Astrophage population that, for some reason, hasn’t grown out of control like it has everywhere else. And that line will lead to a planet that has carbon dioxide. Maybe there’s some other chemical in that atmosphere that impedes the Astrophage? Maybe the planet has a weird magnetic field that messes with their ability to navigate? Maybe the planet has a bunch of moons that the Astrophage physically collides with?

Maybe Tau Ceti just doesn’t have any planets with carbon dioxide in their atmospheres. That would suck. It would mean this whole trip was for nothing and Earth is doomed.

I could speculate all day. Without data, it’s just pure guesswork. And without the Petrovascope, I don’t have data. At least, not the data I want.

I turn my attention to the Navigation screen. Should I mess with it? I mean—I don’t know how to fly this ship. The ship does, but I don’t. If I push the wrong button, I’ll be dead in space.

Actually, it would be worse than that. I’d be hurtling toward Tau Ceti at—I check the info on-screen—7,595 kilometers per second. Wow! A couple days ago, that was over 11,000. That’s what constantly accelerating at 1.5g’s will do for you. Or “decelerating,” I guess. From a physics standpoint it’s all the same. Point is, I’m slowing down with respect to the star.

There’s a button on-screen that just says “Course.” That seems reasonable to tap, right? Famous last words. Really I should just wait until the computer feels like the trip is done. But I can’t help myself.

I tap the button. The screen changes to show the Tau Ceti solar system. Tau Ceti itself sits at the center, denoted with the Greek letter tau.

Ohhhh… that’s what the lowercase t is on the Hail Mary crest. It’s a tau, for “Tau Ceti.” Okay.

Anyway, four planetary orbits are shown as thin white ellipses around the star. The locations of the planets themselves are shown as circles with error bars. We don’t have super-accurate information on exoplanets. If I could figure out how to get the science instruments working, I could probably get much better info on those planet locations. I’m twelve light-years closer to them than astronomers on Earth.