We found one!

[steuard]

Wow oh wow. Universe Today just posted an article about an Earth-like planet discovered around a nearby red dwarf star. (The original source appears to be a UC Santa Cruz press release.)

It's right in the star's "habitable zone" (which mostly means "right temperature for liquid water") and has a mass about 3-4 times Earth's, so a quick estimate is that gravity there might be about 40% stronger than here (it wouldn't be too different than standing in an elevator as it gets going). That's plenty to hold an atmosphere. The planet has its quirks, of course: it's close to its cool sun, so a full orbit only takes about a month. Also, like our Moon it always has the same side facing "in": a planet of eternal sunlight on one side and eternal shadow on the other. Naturally, the only comfortable places to live would be in the twilight region encircling the planet between the extremes of hot and cold, where the red sun burns forever on the horizon.

This is awesome. And it's sooner than most people expected to find something like this, which may mean that planets like ours really are pretty common after all!

Now if only we could find a way to get there.

Comments

[lordhylas.livejournal.com]

Well, a tide-locked planet like this has been the stuff of many a science fiction story. Now perhaps with enough study we can answer those speculations. But we will need better resolution telescopes first. Heck, we don't even know if it even *has* an atmosphere yet. We need some spectroscopy for that. But that can give us a *lot* of info.

[akjdg.livejournal.com]

The propensity for a planet that is tidally locked to its star being conducive to the rise of life is an interesting question. The weather patterns in the atmosphere would be the first question. Assuming the atmosphere didn't all condense on the cold side (and perhaps some gas would remain bouncing around the terminator at least), the convective currents along the terminator would be something. Lots of dramatic thunderstorm-type events, perhaps.

If the planet was endowed with a lot of water, and that did transport to the dark side, you would expect liquid phase water at the base of glaciers (due to pressure and/or geothermal heat). Would such a planet tend to be tectonically dead or alive? If the gravitational lock is anything like the Earth-moon system, that will help drive tectonics and keep some heat about on the dark side.

Also, isn't the Earth's strong geomagnetic field important to the retention of our atmosphere? Perhaps the solar wind from a red dwarf is weaker than from our sun, but an actively circulating planetary core seems pretty important to a stable atmosphere. Especially if one side of the planet is extremely hot.