The new planet we’ve found there is so very near our own that its night sky shares most of Earth’s constellations. From the planet’s broiling surface, one could see familiar sights such as the Big Dipper and Orion the Hunter, looking just as they do to our eyes here.
2012-10-19: Saturn as viewed from the moon vs Proxima Centauri viewed from Saturn
2020-04-25:
The proposal assumes a peak spacecraft velocity of 10% of the speed of light. Once launched out of Earth’s gravitational well, the remaining spacecraft is composed of 2 stages. The first stage accelerates the spacecraft to 0.1c, detaches from the second stage, and performs a smaller perpendicular burn to deflect its trajectory toward the Proxima Centauri AB binary system for a flyby of that solar system. The second stage decelerates a scientific payload and provides power and support during a decades-long period of exploration.
Why is it so difficult to detect planets around Alpha Centauri? Proxima Centauri is one thing; we’ve found interesting worlds there, though this small, dim star has been a tough target, examined through decades of steadily improving equipment. But Centauri A and B, the G-class and K-class central binary here, have proven impenetrable. Given that we’ve found over 4500 planets around other stars, why the problem here?
Proximity turns out to be a challenge in itself. Centauri A and B are in an orbit around a common barycenter, angled such that the light from one will contaminate the search around the other. It’s a 79-year orbit, with the distance between A and B varying from 35.6 AU to 11.2. You can think of them as, at their furthest, separated by the Sun’s distance from Pluto (roughly), and at their closest, by about the distance to Saturn.
The good news is that we have a window from 2022 to 2035 in which, even as our observing tools continue to improve, the parameters of that orbit as seen from Earth will separate Centauri A and B enough to allow astronomers to overcome light contamination. I think we can be quite optimistic about what we’ll find within the decade, assuming there are indeed planets here. I suspect we will find planets around each, but whether we find something in the habitable zone is anyone’s guess.
Gregor J. Rothfuss 