October 16, 2012
Earth Sized Planet 4.4 Light Years Away
In the Alpha Centauri triple star system an Earth-sized planet orbits Alpha Centauri B but too close for comfort.
It is presumably a rocky ball like our own, but it is not habitable. It circles Alpha Centauri B, a reddish orb about half as luminous as the Sun, every three days at a distance of only about four million miles, resulting in hellish surface temperatures of 1,200 degrees.
Imagine we could move that planet into a higher (and cooler) orbit. Well, since it is so hot now it probably has little hydrogen left. So terraforming seems problematic unless the Alpha Centauri system also has a frozen planet in a much higher orbit that could supply the needed water. The energy costs of moving a planet to a higher orbit and also moving hydrogen and oxygen off a frozen planet and into a lower orbit seem prohibitive But maybe 100 years from now the challenge might seem much easier.
Randall Parker, 2012 October 16 09:15 PM
Switching from Fahrenheit to Celsius reduces the temperature appreciably.
Which is more likely to happen first: (1) We (mankind) figure out how to terraform other planets; (2) We improve our bodies to the point where it doesn't matter anymore.
I am reminded of the scene in Peter Hamilton's Void Trilogy where a female character is described as strolling through an airless void wearing nothing but an obscenely short cocktail dress.
If we were able to command the energies required to shift Earth-sized planets from orbit to orbit, we could just as easily build a Dyson sphere right here close to home - no need to travel the 4+ light years.
Anyway, as has been discussed elsewhere, this planet is not so useful by itself, but is a hopeful portent that there may be other planets orbiting that star. It sounds like the signal even from a planet so close to Alpha Centauri was hard for them to detect, so I'm not surprised that they would have trouble detecting one in a more Earth-like orbit; offhand it seems like the signal would be about two orders of magnitude weaker.
Rather than move the planet, just terraform it where it is. It will almost certainly be tidally locked to its star leaving one side icy cold. The cold side could be warmed with mirrors and a 100 mile high wall could be built to keep in an atmosphere. Of course, rather than a 100 mile high planet girdling wall, a roof would probably be cheaper.
"Danger, Will Robinson, danger!"
Sorry, couldn't stop myself.
I guess it's a good thing the Robinsons never got to Alpha Centauri.
One likely advantage of the red dwarf primary is that the star evolves much more slowly than G-type.
here's an idea: why don't all 6.6 billion of you pesky humans migrate to this planet and leave our dear old Earth for my personal kingdom? i promise to take good care of it,and treat all the animals with utmost care.
That's all folks.