I just heard today that scientists at the European Southern Observatory have discovered a possibly Earthlike planet orbiting another star at just the right distance to support liquid water! The star is Gliese 581, and the planet is unceremoniously named Gliese 581 c. Gliese 581 is a red dwarf star, which is a main-sequence (young adult to adult), low-mass star. Red dwarfs get their name from what is called their emission spectrum. Any object with the least bit of heat will emit photons of all sorts of wavelengths. Longer wavelengths fall in the red, infrared and radio, and short wavelengths in the blue/violet, ultravioilet and X-Ray spectrum. The hotter the object, the more high-energy, short-wavelength light will be emitted. Red dwarfs are relatively cool, because their low mass means a slower rate of fusion, thus making them appear red.

From what I've read, this new planet stays warm by the virtue of its closeness to the star. It orbits at one fourteenth the Earth-Sun distance, taking only thirteen days to make a revolution. At such a range, it is expected to be tidally locked to the star, with one side always facing inward. It was once thought that this would make one side scorching hot, the other side freezing, and both sides inhospitable to life. However, we now know that even a modest atmosphere can help spread the heat around, keeping both sides warm. We haven't been able to see the planet directly: it was discovered with radial velocity measurements. That is, using the doppler effect to measure the wobble of the parent star as its planets tug it around. The planet is about five times Earth's mass and one and half times its diameter, and according to models, it's likely to either be a rocky, very Earthlike planet or drenched with oceans. A good summary can be found at the Bad Astronomy website.

I really hope that we are able to directly image this planet in the near future. Until then we can't really say what this thing is made of, and I'm anxious to know whether this truly is an Earth-type planet. If it is, then this will be very exciting. It would conclusivelly prove that M-stars, which were once thought to be too cool for habitable planets, can support Earths and widen the search for extraterrestrial life and intelligence. That and provide a nifty place that our kind may go someday.

As I think about this, I'm tempted to fantasize about what this planet could be like. It'd be interesting to know its seasons, weather, plate tectonics... and of course what life there could be! I'll be the first one to predict blue plants. Hearing about these things make me want to imagine what really could be out there. It'll be a little while, though, before I'll have much more to say as to what I imagine to be out there. But I can guarantee you that those thoughts will make into something that I'll show on this site.