h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

... I probably said it in the wrong place. :-) This is how I'd have written this entry, as explained here (http://www.h2g2.com/F32500?thread=47881): Alpha Centauri is a star visible from Earth, among thousands of other stars. It is in the constellation Centaurus, the Centaur, and can be viewed with the naked eye from the southern hemisphere and parts of the northern, as the fourth brightest star in the sky. It is actually made up of three stars, Alpha Centauri A, Alpha Centauri B and Proxima Centauri, making it a trinary or triple system. Alpha Centauri is our nearest stellar neighbour, at about 4 light-years away. Alpha Centauri A and B are quite similar to the sun, Alpha Centauri A in particular has a luminosity and surface temperature almost exactly the same as our sun(footnote: It's spectral classification is G2 like the sun's.). Alpha Centauri A and B together are a binary, orbiting each other every 80 years. The third star in the system, Alpha Centauri C, better known as Proxima Centauri, is the nearest star to our solar system, hence its name. Proxima Centari is a small red dwarf star, and it is unclear whether it is gravitationally bound to Alpha Centauri A and B, or whether it is just passing through the system. It was only discovered in 1915. Could there be life there? No one has yet been able to find a planet there yet so it's too early to tell. Let's hope that if there is intelligent life there, they have a good sense of humour. Remember, current broadcasts of the Spice Girls will reach Alpha Centauri in only four short years. Furthur Reading: http://monet.physik.unibas.ch/~schatzer/Alpha-Centauri.html - more information on the Alpha Centauri system, including a discussion of whether or not it is suitable to support life http://antwrp.gsfc.nasa.gov/apod/ap960526.html - a picture of Alpha Centauri, from The Astronomy Picture of the Day