Astronomers have recently discovered that Gliese 581 g, a planet in a star system 20.5 light-years from Sol, is the first known extra-solar “Goldilocks planet,” with a temperature just right for liquid water, and life.
However: The planet is tidally locked, presenting always the same face to its star, like the Moon to the Earth. Which implies a hot, bright side, a cold, dark side, and an intermediate equatorial zone.
I would say there’s definitely maybe possibly life there. From the descriptions of it being tidal locked, it’d imagine any wide-ranging creature would be built pretty sturdily.
I totally think it’s worth going there to find out. The first thing I thought was “who’s going to be making a probe first?” While looking around for the feasibility of such an idea, I found this:
Which makes me sad and hopeful. It, and finding out that ion drives max at 68,000 mph, makes me realize the actual scope of going somewhere that’s 20 LY away. It’s not happening anytime soon. Not only does the thing have to get there, it has to land, and work perfectly, the first time. It’s computer will have to recon a landing area itself as well. The 20 year wait for your return data is easy after you’ve waited 100 thousand years for the probe to get there. I hope someone remembers to listen, and remembers how to speak the probe’s language. We’re going to have to get much faster before we can think of going there in any meaningful amount of time.
Does anyone know if Kepler is being sent out there for some more photos? It may not be calibrated correctly, but can we get some better pics of the planet’s surface any time soon?
From its description, it is quite possible there’s some type of life on there. I would think there’s some type of plant life.
I’m optimistic there’s life there (I’m also fairly optimistic that there is life elsewhere in our own solar system.)
As for the ~85,000 year round trip: I’m not saying we’ll be cruising by Gliese 581g* next week, but . . . a current retiree was born in a world where a trip to Mars was “no way, no how, fergetabouddit, yer nuts pal, go bark at the moon”, and now lives in a world where a trip to Mars is “meh, kind of expensive dontchathink, and not all that exciting.”
50 years ago we weren’t sure we could get to the moon.
110 years ago we weren’t sure heavier than air flight was possible.
Tons of ho-hum modern technology was science-fantasy a few generations ago; cell phones, internet, the flesh light, etc.
Again, I’m not saying we’ll get there in the next few decades, but I wouldn’t put it beyond humanity to figure out a way to get there (or to the current flavor-of-the-week) within a century or so.
*(countdown to new name: 3, 2, 1 . . . )
With a mass 3-4 times that of Earth I should imagine it is likely to have attracted a dense atmosphere like that of Venus, making it completely inhospitable to life. If not I imagine the mass would make land creatures small and compact unable to support more complex and intelligent creatures. But perhaps if there are oceans larger creatures could have evolved there.
Kepler doesn’t work that way. Kepler uses a wide-field imager to study a field of about 150,000 stars at the same time. Computers are then used to analyze the brightness of each star, looking for signs of planets occluding the star and lowering its brightness. Kepler is not designed for high-resolution imaging of single stars.
We do not have any telescopes that are capable of seeing an earth-sized planet around another star directly. We can only discover these planets by inference, either by detecting the doppler-shift of the spectra of a star as it wobbles due to the planet’s gravity tugging the star around, or by measuring the light output of the star as a planet crosses in front of it. The former technique only works with big planets orbiting close to small stars, while the latter only works for star systems which have the orbital plane pointing straight at us so that the planet crosses in front of the star from our vantage point. I don’t know if Gliese 581g is in such an orientation. It seems unlikely.
The Terrestrial Planet Finder is (was?) an orbital telescope array powerful enough to detect planets around other stars directly, by blocking the star’s light and reading the reflected light from the planet. It still wouldn’t be able to resolve the actual disc of a planet, but by looking at reflected starlight we’d be able to measure the atmospheric composition of the planet by looking at how the starlight spectra changed after going through the atmosphere of the planet. Unfortunately, the Congress pulled funding for TPF in 2007, leaving the program in limbo. Had Congress not done this, one TPF mission would have launched in 2014, and the other, more advanced one in 2020.
The next generation program after TPF would be the first one to actually image a planet, and that mission was called, unsurprisingly, the Planet Imager. The Planet Imager was to be an array of at least five TPF-type telescopes, arranged in a long-baseline array. This huge telescope array would have been able to image the closest planets to a resolution of about 25 X 25 pixels - enough resolution to see continents and oceans, and maybe huge deserts and forests, but that’s about it. Such a mission wouldn’t have launched until at least 2030 or 2040, and now with TPF in limbo it may never launch at all.
In the distant future, we could build telescope arrays of hundreds of Hubble-sized mirrors spaced several hundred kilometers apart, which would allow us to resolve planets around the nearest stars to maybe 100 X 100 pixels. It would look something like this (that’s a 128 X 128 thumbnail of earth).
That’s probably the best we could ever hope for in our lifetimes. In the distant future, gigantic arrays the size of Earth’s orbit, along with adaptive computer analysis might allow us to image details on the nearest planets down to a few hundred meters in size. But at that resolution you start running into physical limits (there just aren’t enough photons to measure).
The mass is 3-4 times that of earth, but the planet is also bigger, making surface gravity only 1.2-1.4 that of earth.
But it’s not gravity that determines the density of the atmosphere. Venus is almost identical in size and mass to the Earth. Venus has a dense atmosphere either because on Earth plant life slowly absorbed all the CO2 in the atmosphere and locked it away in mineral formations, or perhaps a collision event early in Earth’s history blasted much of the atmosphere away. Or a combination of both.
Not exactly doubting you Sam but resolving anything at this distance with a telescope seems inconceivable to me.
Here is a picture of Pluto made by the Hubble Space Telescope. Granted Pluto is smaller than Gliese581g is but it is a helluva lot closer.
I get these new telescopes would be far superior to Hubble but I’d be shocked at them getting a snapshot of a fuzzy blob of a planet around another star much less resolve continents.
One of Larry Niven’s short stories has a time traveler make a mistake that destroys Earth’s Moon back in azoic times. When he returns to the present he finds that Earth has an atmosphere like that of Venus – the assumption being that the Moon’s gravity scoops up some of the accumulation of greenhouse gases in Earth’s atmosphere, and thus makes life possible here. I don’t know if that’s true. If Earthlike life requires a Moonlike moon, then life-bearing planets would be extremely rare; this local system we’ve got, with a satellite not all that much smaller than the primary, and big enough to count as a planet in its own right if it had an independent orbit, is very highly unusual.
Yes, I’ve done more reading on experimental propulsion since last night. I’m more hopeful, but think we’re gonna have to work like bees to make a feasible probe even launch within my lifetime. Personally, I’m still turned on by the Bussard Ranjet, but the other ideas, such as fusion rockets, seem more likely to be fruitful soon.
Large moons are not uncommon. Our moon is the 5th largest in the solar system. The largest is Ganymede which is bigger than Mercury and just a little smaller than Mars.
Pluto has been demoted as a planet but Charon, which orbits it, is roughly half the size of Pluto (if it is the ratio between planet/moon that is at issue).
I am not sure such things are “unusual” in the universe.
Not true, Cisco. It was generally believed in the 1950’s that we would eventually travel to the moon and it was fairly commonly believed that we would eventually travel to the other planets of the solar system. This website tells about an article in Look (a pretty mainstream magazine) written in 1957 about future space travel:
Space travel was considered quite possible among many people even as far back as the 1930’s. Furthermore, the basic idea of an airplane was considered quite reasonable back at least as far as the 1880’s:
Possibly true. In fact, I imagine astronomers are divided over that question. One star system isn’t much of a representative sample to generalize from anyway.
Yeah, sensationalism has always sold well, but there were plenty of people who didn’t believe it would really happen. As recently as the late 1800s, the consensus among the world’s top scientists was that a radio signal would never be sent more than a few hundred yards. As you know, an amateur thoroughly smashed that notion.
