Proxima Centauri b, better known as Proxima b, is an Earth-like planet that circles Proxima Centauri, the nearest star to the Sun. It could have life, maybe even intelligent life. It was discovered by a telescope in the deserts of Chile just last month, August 2016. It is a huge find.
Exoplanets: since 1991 astronomers have discovered some 3,500 exoplanets, worlds that circle other stars. But nearly all of them are uninhabitable: they are too hot or too cold or too big or too small to support life as we know it.
Only a dozen or so habitable planets have been found so far. Last year NASA was making a big deal about Kepler-452b, and that was 1400 light years away. Proxima b is only 4.22 light years away!
No one on Earth has seen Proxima b yet. But we know it is there because its sun wobbles. From the wobble we can tell that, compared to Earth, Proxima b is at least 1.2 larger, 20 times closer to its sun and, because its sun is a red dwarf star, 30% colder.
The bad news:
- Deadly radiation: red dwarfs are known for outbursts of deadly radiation. Its sun has been quiet for as long as we have been looking at it, but there is no telling what it has done in the past.
- Tidal lock: there is a good chance that Proxima b, like Mercury, always has the same side facing its sun. That would make one side too hot and the other side too cold.
New life: The next step is to see if it has an atmosphere to see what is in its air. If it has oxygen, that will be a strong sign (but not proof) that it has life. If it has both oxygen and methane, that will be an even stronger sign. Unless we catch it crossing in front of its sun, we will not know about its atmosphere till the middle 2020s when telescopes will be powerful enough to observe Proxima b directly.
New civilizations: Proxima b is not sending any powerful radio messages to Earth, we know that much. But it could be using radio or television or something like it for its own purposes. If so, we might be able to pick that up. That would be mind-blowing.
To boldly go: It took New Horizons ten years to reach Pluto, and Proxima b is some 7,000 times farther away! But Stephen Hawking, one of the world’s greatest minds, and Yuri Milner, a Russian billionaire, are working on inventing a spacecraft that could go up to 20% the speed of light. It would be too small to carry people, but it could carry instruments. It would take at least 21 years to reach Proxima b and another four years for any pictures and findings to get back to Earth, but there are people alive today who might live to see it.
– Abagond, 2016.