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Kepler-186f: Most 'Earth-Like' Alien World Discovered
astroengine (1577233) writes "About 500 light-years away in the constellation Cygnus lives a star, which, though smaller and redder than the sun, has a planet that may look awfully familiar. With a diameter just 10 percent bigger than Earth's, the newly found world is the first of its size found basking in the benign temperature region around a parent star where water, if it exists, could pool in liquid form (abstract). Scientists on the hunt for Earth's twin are focused on worlds that could support liquid surface water, which may be necessary to brew the chemistry of life. "Kepler-186f is significant because it is the first exoplanet that is the same temperature and the same size (well, ALMOST!) as the Earth," David Charbonneau, with the Harvard-Smithsonian Center for Astrophysics, wrote in an email to Discovery News. "Previously, the exoplanet most like Earth was Kepler-62f, but Kepler-186f is significantly smaller. Now we can point to a star and say, 'There lies an Earth-like planet.'""
If I do, I could be there in what, 25k years..round about?
After all, Mericans are always saying to me "if ya don't like it, git'out".
If we are quiet, maybe we'll get lucky and they won't notice us....
I am very small, utmostly microscopic.
No.
There have been several studies of tidally-locked planets around M-dwarfs which refute this.
Simulations of the Atmospheres of Synchronously Rotating Terrestrial Planets Orbiting M Dwarfs: Conditions for Atmospheric Collapse and the Implications for Habitability, M. M. Joshi, R. M. Haberle, and R. T. Reynolds , Icarus (1997)
A Reappraisal of The Habitability of Planets around M Dwarf Stars, Tarter et al. (2007), Astrobiology,
Basically atmosphere and ocean circulation transfer the heat, and you get a relatively habitable earthlike environment.
Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist
Because the future of humanity depends on getting off of this rock eventually.
If they are advanced enough to travel here then they've had their own version of the Kepler telescope for 500 years and have known at the minimum that Earth has liquid water, oxygen, and chlorophyll (I think that can be picked up used spectroscopy). Basically anyone advanced civilization nearby probably has known about Earth as a life-bearning world long before humans came along.
Just a cool thought to counter the idea that we're hidden until someone detects radio.
Earth-like depends on context. For me... if it has free wifi, it qualifies.
How much of this "habitable zone" factors in water's ability to be liquid to to pressure? Too thin it vaporizes (Mars). Too much, it vaporizes (Venus). Merely being the right temperature isn't enough.
Also, having a magnetic pole strong enough to shield it from the solar wind, so what does wind up in the atmosphere doesn't wind up in space.
Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
An engineering problem in the sense that there is not enough matter in the universe to accelerate a spacecraft at 1 g for 2 years using any currently plausible propulsion method.
>The sooner we launch one, the sooner our descendants get to hear back from it.
Not necessarily. Or more precisely by the time they hear back from it the information will likely be completely redundant.
At present all our mature propulsion technology is very much focused on planetary usage. Rocketry is the only one at all suitable to operating in space, and it's *horribly* inefficient in terms of specific impulse, which will be *the* deciding factor for interstellar travel. Ion drives show immense promise, already completely trouncing chemical rocketry in terms of specific impulse, but it's a technology very much in its infancy and the absolute thrust current engines can produce is miniscule, useful for little more than station-keeping and lining up gravitational slingshot maneuvers. If we launched an interstellar probe with today's technology then it's quite likely that a second probe launched 50-100 years from now would be able to make several round trips before today's probe ever got anywhere close to the target. For a mission whose expected payoff is centuries away that sort of thing is well worth considering. Much like Voyager making its pokey way out of the solar system, the value of an interstellar probe built on current-gen technology would be primarily in learning about the beginning of the path, not the destination. And unless there's some completely unexpected navigation hazard in the gulf between stars there's unlikely to be much to learn worth the cost of the probe.
Now what might be an interesting mission with current or near-term technology is a gravitational-lens telescope - rather than sending a probe towards Kepler-186f we send a telescope "eyepiece" in the opposite direction, and when it reaches a distance of only about 700AU (0.011 light years, ~10x Voyager 1's current distance) away from the sun we could start to use the sun's gravitational field as an immense lens in a telescope so powerful we could count the pebbles on 186f's hypothetical beaches. Maybe even individual grains of sand. Not to mention everything else we might see in that general direction. The downside to such a telescope is that it's extremely difficult to substantially change the target. With a telescope 700AU long even a few degrees of change requires moving your eyepiece across a distance rivaling Pluto's orbit. Still, with a clever flight plan we could get immensely detail information about dozens or hundreds of other star systems as our eyepiece slowly swept out a few degrees of motion. The only real question is, is 186f really interesting enough to be the first target? I would imagine looking toward the galactic core would offer far more interesting things to see.
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