Slashdot Mirror
Earth-Like Planet That Could Sustain Life Found
astroengine writes "An exoplanet, 20 to 50 percent the mass of Earth, has been discovered 20 light-years away and it appears to have all the ingredients conducive to sustaining life. It has enough gravitational clout to hold onto an atmosphere and it orbits well within the 'Goldilocks Zone' of its parent star. However, it would be a very different place to Earth; it is tidally locked to its star, creating one perpetual day on the world. Interestingly, this may also boost the life-giving qualities of the exoplanet, creating stable temperatures in its atmosphere."
This is where I stopped reading:
"Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say that the chances for life on this planet are 100 percent. I have almost no doubt about it," Steven Vogt, professor of astronomy and astrophysics at University of California Santa Cruz, told Discovery News.
Chances are 100%. Almost no doubt.
As an electrical engineer, I feel I have a fairly firm grasp on how people figure out a lot of these seemingly extremely complex things.
Magic.
When you're afraid to download music illegally in your own home, then the terrorists have won!
20 light years is millimeters of astrophysical distance.
It amazes me we have been observing space so long and yet we only now have detected this planet.
It just goes to show how incredibly likely it is to find planets like Earth everywhere in the galaxy.
The summary is incorrect. The exoplanet has "a mass three times larger than Earth's", not 20% to 50%
My math might be a little off, but if we accelerated at g half-way there and decelerated at g for the rest of the way, it would only take a ship about 6.04 years to get there. But thanks to Einstein ruining all our space travel fun with relativity, we of us left on Earth would think the journey took 21.86 years. So there and back would seem like 43.7 years to us.
Just 20 light years away is good news! One thing that always bothers me when I read about E.T. life, is the fact that we get excited when we find water or an Earth-like atmosphere somewhere, thinking there should/might be life there. We should factor in the possibility that life may evolve entirely differently from us, without requiring water or nitrogen/oxygen. In that case though, we can't really know how it will have evolved as we have no reference of evolution other than ours. So let's wait, or just go there as soon as we can as aliens.
Look at where the most biodiverse regions are on Earth. They are in the equatorial zone, where the climate is stable.
Venus and Mars are also rocky "Earthlike" planets orbiting roughly in the habzone ("goldilocks" zone).
I'd like to see truly terrestrial planets as much as (more than, probably) the next guy, but I think the reportage here is a bit hyped. Especially given a ~3x mass, that gives it roughly 1.44x the surface gravity (and higher likelihood of a Venus-like atmosphere).
-- Alastair
genetically modify humans to live in a wider variety of environments
That would never make it through the intergalactic genetic engineering subcommittee. Their chest-pumping and rhetoric would stop it before it hit the hull floor.
(Posted from the year 2089, see you guys soon! The future is great, but the space-beer is a little watered down.) Yankees win in 66, America is nuked by Eskimos in 70, and 89 is to be the year of the Linux holodeck neural interface.
'We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.' RPF
intriguing is the fact that we are studying the planet as it was 20 years ago, not as it is present day. In roughly 100 years we've managed to screw up this planet to no end. Things could be quite different on gliese 581g at this moment and we would not know it. Assuming we could travel at the speed of light and made it there in 20 years, the inhabitants may have already turned most of the planet to concrete and smog. If it is indeed inhabited.
boycott slashdot February 10th - 17th check out: altSlashdot.org
I actually work quite closely with 2 of the authors of the paper that reports these results. Any questions? I'll try to respond to posts between now and 2 October.
Well, there's lawyers covered, then.
Cheers,
"What in the name of Fats Waller is that?"
"A four-foot prune."
We're here not just because we're in the Goldilocks zone, but also because we're a double-planet (earth and moon). Lots of gravitational stress to help encourage crustal slip along fault lines, and free water to help with the slippage. A runaway greenhouse effect caused by much higher CO2 concentrations converts the water to H2SO4. Once the water is gone (it's still liquid at depth even at 150C because of the pressure), the plates lock up completely, and you get Venus.
My what exciting times we live in. Just think... it has only been around 100 years since we realized the universe is organized into galaxies. Only a few hundred since we realized that the Earth is not the center of the universe. Sometimes it is hard to have faith in the future... but discoveries like this touch that small part of me that hasn't become jaded.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
First, TFS is wrong. This planet is 3 to 5 times the mass of the Earth, not 30%.
The article also won't tell you what is speculation and what they've actually seen. The planet was detected through radial velocity measurement of the star. That pretty much means the only thing that has been measured is the planetary mass times the sine of the inclination of its orbit relative to the sun-Gl581 line. Hence the large uncertainty.
When they talk about atmospheres they are speculating. There is no way to tell if this planet has an atmosphere, although the large mass helps the case. There's no way to tell if the planet is covered in an 100 mile deep ocean or if it is entirely dry other than by speculating based upon the composition of the host star. With no eclipses and a small planet to star distance it's going to be a while before we know for sure about either.
When they are talking about tidal locking they are also speculating. While the planet would almost certainly be tidally locked to the star if it were the only planet in the system, it could exist in an orbital resonance with another planet that throws off the tidal locking, or it could have a large moon in close orbit, which would also do the job.
I also haven't looked to see which version of the habitable zone definition they are using. I would suspect the run-away greenhouse to ice-line version.
Support SETI@home
there is probably some sort of maximum initial spin rate, and even given that rate the planet might be guaranteed to be tidally locked at this point.
Glad you answered your own question. We have a good idea of what rotation rates are possible when planets form in a disk, probable rotation rates are basically a function of composition and mass (very small objects such as small moons, asteroids, and fragments are more complicated because their rotation rates are going to be affected by frequent impacts, but even then there's a limit to what gravity can hold together)
Basically, the planet in question--Gilese 581g, is very very very old. It orbits a red dwarf star whose lifetime is in the billions of decades--20-30 billion years likely (too lazy to check for an actual figure, but it's much longer than the 10 billion years for our sun). Based on the current age of the system it (and apparently every other planet in that system, from the bottom of the wiki page on tidal locking) should already be locked.
20 light years is *about* 1.25 million AU. Voyager is 113 AU from the sun, in under 4 years it will be 125 AU from the sun. If we pretended Voyager 1 was heading the in right direction it would be 1/10000 of the way there. Or if we imagined that the planet was 10 meters away, Voyager has travelled 1mm of the way there. About 350000 AD, it would arrive!
So here I am, reading on Slashdot about two teams of astronomers with probably over 100 years of education between them, more doctorates than you can shake a sick at, who are publishing a paper in the Astrophysical Journal about this new discovery, and I find this post by tomhudson essentially calling them idiots.
Only on Slashdot.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
As a tautology expert, I have a fairly firm grasp when grasping things fairly firmly.
Finally had enough. Come see us over at https://soylentnews.org/