We are living in the greatest age of planetary discovery since Galileo looked at Jupiter, and that age may be on the verge of delivering one of the most exciting discoveries imaginable: earth-like planet[s] around Alpha Centauri, AKA Rigel Kent or ACen. Just the name Centauri brings on dreamy eyes in the sci-fi and space exploration community alike. At 4.37 light-years away, the three stars making up the Centauri system are by far our closest stellar neighbors. Via reader/writer “F,” planet hunters pouring over data from the most famous star system outside of ours have found strong hints of an earth-sized world, and there could be more:
The Planetary Society— [A]stronomers using the HARPS instrument on the 3.6-meter telescope at ESO’s (European Southern Observatory) La Silla Observatory in Chile have reported the discovery of a slightly larger than Earth-mass planet orbiting the star Alpha Centauri B. This is the first discovery of a planet in our closest neighbor system of stars, and the least massive exoplanet ever discovered around a star like the Sun.
“There is not a more exciting result for an individual star, even with the long line of spectacular results from the last 2 decades. The indication that our nearest neighbor has rocky planets is incredible. Furthermore, statistical results from the NASA Kepler mission suggest that where there is one, there are usually several rocky planets. This leaves open the possibility of a terrestrial planet in the habitable zone – in fact, I think this strengthens the speculative possibility of a habitable world in the alpha Cen system.”
KABOOM! I can honestly say, a shiver went down my spine when I followed the link left by F and read the post.
Alpha Centauri is a classic binary star system. Two twin suns, A and B, orbit each other every 80 years in an elegant, joint elliptical orbit with major and minor axis varying between the distance of Neptune and Saturn are from our sun at farthest and cloest approaches respectively. Astronomers speculate the system could be full of debris, vast braided rings that would make Saturn envious, asteroid belts on top of asteroid belts, or it could have long since been cleaned up spic and span compared to our solar system through accelerated ancient collisions and accretion. A red dwarf star, dubbed Promixa as it is technically the closest to us, is thought to be associated with ACen and lingers on the edge of interstellar space a quarter light year from the binary.
Reaching any of these stars would take more efficient and far more powerful propulsion systems than anything we have now. With existing chemical rocket engines, we’re still talking about something on the order of ten thousand years in best case scenarios. But a next-next generation ion drive, or a combo of futuristic light sails or fusion drive, etc, might actually get us there in something like a couple of thousand years. If we can get to just two or three percent of the speed of light, we’re there in a couple of hundred years and five to ten percent of the speed of light means the probe reaches the system within a single human lifetime!
Missions of that duration present engineering challenges beyond mere propulsion, it would mean significant jumps in onboard power requirements and component reliability to say the least. But thanks to the proximity of ACen, it’s tantalizing close to our xurrent technological grasp and near term future vision. We can actually begin to think about mounting such a mission within the lifetime of humans beings living now.
They call us non believers, and that’s saying mildly in some cases. But I do have beliefs, for lack of a better word, I believe near term machine descendents of the clunky rockets and computers in our technological inventory will make it to the stars. The very first alien star and exoplanet[s] we will visit by proxy and in whatever passes for a person at the end of this millennium will be Alpha Centauri.