Brian G Turner
Fantasist & Futurist
- Nov 23, 2002
A long-term study of Alpha Centuari has dispelled fears that life couldn't survive in that star system.
NASA's Chandra X-ray Observatory made observations every six months from 2005, and discovered that the radiation wouldn't be so bad as originally expected.
At around 4 light years away, Alpha Centauri is the nearest star system to Earth. It comprises three stars: Alpha Centuari A, which is very similar to our sun; and Alpha Centuari B, which is a smaller star that orbits it to form a binary pair. At a very extended orbit around both is the small red dwarf Proxmia Centauri.
Originally it was thought that interactions between Alpha Centuari A and B would result in a flood of radiation that could sterilize any nearby planets. Although no planets have yet been found around these two stars, data from Chandra shows that radiation levels are actually similar to our own system.
So if any planets a safe distance from those stars might be capable of supporting life - not just indigenous where conditions allow, but also future colonists from Earth.
However, it's not all good news - Promixa was found to emit deadly bursts of X-Rays during solar flares during its solar cycle. This does not bode well for Proxima b, a rocky planet about the size of Earth that has already been detected in orbit around Proxima, in what should have been a habitable zone.
There remains hope for the future, though - the James Webb telescope will take a closer look for planets in the Alpha Centuari system, after it launches in 2020.
Additionally, the race is on to design a space probe capable of visiting Alpha Centauri, with the private company Breakthrough Starshot aiming to have a viable project "within a generation", while NASA is also looking to send its own interstellar probe there in 2069.
[IMAGE: Alpha Centuari A and B are so close that they appear as one star in the above image, with Proxima circled red.]