This is a big one, and it happens several years earlier than I had expected. A planet of about five times Earth mass, one whose radius is only 1.5 times that of our own world. Moreover, a planet that’s smack in the middle of its star’s habitable zone, with a mean temperature estimated at between 0 and 40 degrees Celsius. The models in question say that this is a rocky world, and its temperatures tell us that oceans could exist there. The first detection of a planet where carbon-based life could conceivably exist makes this one a find for the history books.
The star is Gliese 581, already known to be home to a planet of Neptune mass and a possible third world about eight times as massive as Earth. It’s an M-class red dwarf, far smaller and cooler than the Sun. The new planet, the smallest found up to this point, orbits it in 13 days. Gliese 581, it should be noted, is comparatively close to our own Solar System, about 20.5 light years away in the constellation Libra. Radial velocity methods seem to have been made to order for this small star and the planets that circle it.
Image: Artist’s impression of the planetary system around the red dwarf Gliese 581. Using the instrument HARPS on the ESO 3.6-m telescope, astronomers have uncovered 3 planets, all of relative low-mass: 5, 8 and 15 Earth masses. The five Earth-mass planet makes a full orbit around the star in 13 days, the other two in 5 and 84 days. (c) ESO.
Xavier Delfosse (Grenoble University), a member of the discovery team, has this to say about the significance of the new world:
“Liquid water is critical to life as we know it. Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X.”
Yes, and Gliese 581, with clear evidence of a second ‘super-Earth’ in an 84-day orbit (well outside the star’s habitable zone) and its Neptune-class world (5.4 day orbit) as well, is one of the most interesting planetary systems analyzed to date. We’ve looked many a time in these pages at what a terrestrial world around a red dwarf might be like on the surface. Surely tidally locked to its parent, with that dim red sun eternally fixed in the same place in the sky. Given a thick enough atmosphere, heat transfer could occur that keeps the dark side warm enough to prevent its gases from freezing out. We’re left with the possibility of a temperate region on the day side that could, for all we know, support life.
Image: Gl 581. Just a dot at screen center, but perhaps home to the first habitable world ever detected. Credit: Sloan Digital Sky Survey (via systemic).
The new planet may not be anything like this, and it will take more work — and surely space-based instrumentation — to learn what its true characteristics are. But ponder a planet where infrared predominates rather than visible light, and periodic flare activity acts as an evolutionary stimulus. The consider the long lifetimes — more than a 100 times the Sun’s paltry ten billion years — that M-dwarfs have to let evolution work its wonders. There are arguments to be made for and against this scenario, but if it’s remotely true, then the number of habitable planets in our galaxy may be far higher than we’ve previously believed.
Physicist and science writer Douglas Blane recently interviewed astrobiologist Giovanna Tinetti on the subject of hunting for life-markers on exoplanets. Part of their discussion involved M-dwarfs, with Tinetti recalling a talk at Caltech by John Raven (Royal Observatory, Edinburgh), who described his work with Ray Wolstencroft on M-dwarf habitability. What kind of photosynthesis might happen on a world lit by the longer wavelengths of such a star? From the interview:
They provided a scheme for photosynthesis that uses three photons instead of two, as vegetation does on Earth. They showed that you can still have photosynthesis with a cooler star. So that started me thinking about what would happen to the red edge [photosynthesis shows high reflectance at the far red of the optical spectrum, a useful signal of the presence of vegetation]. I showed that it would be shifted, so you would need to look for a slightly different signature.
The next question of course was whether planets of such a star would have the same atmospheric characteristics as Earth. Now a scientist called Joshi had already provided a 3-D model for a terrestrial planet in the habitable zone of an M-star. He’d shown that you probably need more greenhouse gases to warm up the area not illuminated.
This is because for such a cool star the planet has to be very close. So it could be tidally locked, with one face always illuminated and the other always dark. That meant you needed a circulation of the atmosphere and a particular composition. We put that model together with my calculations on the shifted red edge, and discovered that the strength of the edge feature on an M-star terrestrial planet can exceed that on Earth, given the right conditions.
Of course, we can only speculate about the new Gliese 581 planet because thus far all we really have a read on is its orbital period, distance from the star and minimum mass. Even so, what a find, one that will surely spur yet more interest in the red dwarf category that accounts for up to 80 percent of the stars in our galaxy. Kudos to the discovery team and the amazing HARPS (High Accuracy Radial Velocity for Planetary Searcher) spectrograph, located on ESO’s 3.6-meter telescope at La Silla (Chile). HARPS detected velocity variations in this star between two to three meters per second — we’re talking about the speed of a brisk walk!
Planet hunter extraordinaire Michel Mayor (Geneva Observatory) has this to say about HARPS:
“HARPS is a unique planet hunting machine. Given the incredible precision of HARPS, we have focused our effort on low-mass planets. And we can say without doubt that HARPS has been very successful: out of the 13 known planets with a mass below 20 Earth masses, 11 were discovered with HARPS!”
All true, and you have to like where this is going. Mayor again:
“And we are confident that, given the results obtained so far, Earth-mass planets around red dwarfs are within reach.”
Oh for the dedicated (and lengthy) observing run sufficient to let HARPS do its number on Centauri B! And if you’re wondering about previous super-Earths, Gliese 876 does indeed have a planet with a minimum mass in this same range — 5.89 Earth masses — but its orbit (completed every two days) takes it too close to its star for liquid water to exist. Likewise, the icy world OGLE-05-390L weighs in at 5.7 Earth masses but is much more distant from its primary and out of the habitable zone.
The upcoming paper in Astronomy and Astrophysics is Udry et al., “The HARPS search for southern extra-solar planets : XI. An habitable super-Earth (5 MEarth) in a 3-planet system.” I’ll point you to the abstract as soon as it becomes available. Thanks to Darnell Clayton for additional information on this story.
Update: Here’s a link to the paper on this work; thanks to Malcolm Ramsay for the address.
Hmm did a quick search but couldn’t find anything relating to Gliese 581’s composition. Do you know offhand what it’s metalacity (sp) might be? This could be very interesting and have some impact on planetary formation theory since the impression I had is that Gliese 581 is an older star and should be metal poor.
This is very cool news!
JD: Gliese 581’s metallicity is -0.33 +/-0.12 according to the Extrasolar Planet Encyclopedia, so it’s only slightly more metal-poor than the Sun. That link also gives an age for Gliese 581 of 4.3 billion years, so it’s actually slightly younger than the Sun.
The next few years are going to be so exciting. Who would have thought a few decades ago that the humble M dwarf would get so ‘sexy’?
Bring on the TPF!
P
Cool news indeed. And M-dwarfs are suddenly the hottest topic of the day!
…give us spectrum! Please!! Spectrum!!! Oh no-no-no, I can’t believe it…
The dream came true! :-)
From the Second Gliese Catalog:
Gliese # 581
RA (1950) 15h 16m 50s
Dec (1950) -07d 32m.4
Proper Motion 1.224 arc-sec/yr
Proper Motion Position Angle 256d.3
Radial Velocity -9.4 km/sec
Spectral Class dM5
Apparent Magnitude 10.56
B-V +1.60
U-B +1.23
R-I +1.10
Trigonometric Parallax 157.9 milliarc-sec
Absolute Visual Magnitude 11.55
Bonner Durchmusterung Catalogue # BD-07 400
Epoch 2000.0 Coordinates
RA 15h 19m 30s
Dec -7d 43m 19
20.6 ly distant
This star is in the Millennium 2000.0 Atlas, Map 789
I read a novel a few years ago about a civilization on a planet like this. The habitable zone was restricted to the sun-facing side (of course) and had a large island in the middle, so that from space, the planet resembled an eye. It had an ocean hundreds of km deep and much of the story was concerned with a deep-sea mission, and with complications resulting from the properties of the various forms of ice that formed at depth. Does anybody remember the name/author?
Bret
Thanks, sigh brain cramp, didn’t even think to go there, just did generic web searches. So apparently Gliese 581 is not one of the early class M’s? This should be interesting and also should be a huge goad to the researches to push the art further.
Some information: http://www.solstation.com/stars/gl581.htm
Question: I’ve read conflicting info…can red light cause photosynthesis?
i’m reading the astrobiology journal article that says its possible, but others say it is not.
djlactin,
The novel you describe sounds similar to (but clearly not the same as) Across the Sea of Suns by Gregory Benford (1984).
From wikipedia (http://en.wikipedia.org/wiki/Across_the_Sea_of_Suns):
“Radio astronomy on the Moon in 2021 reveals the presence of life by a nearby red dwarf, on a tide-locked planet.”
I believe it was a volcano at the center that also gave the planet the appearance of an eye.
“What’d you get Charle Brown?”
“I got a rock,” he said solemnly.
Maybe it’s just a rock.
I was about to ask for sci-fi about similar planet setups, intrigued by the concept of a sun fixed in the sky, and that Gregory Benford novel seem like a good place to start. Thanks. Any other suggestions?
This discovery will be sure to spark new ideas and even new technologies!
Preprint of the paper is available here- http://exoplanet.eu/papers/udry_terre_HARPS-1.pdf
Yes, this is great news! Although it is only a beginning, and I am a bit less optimistic about chances for biological life: 0.073 AU (orbital period almost 13 days) is very close, i.e. strong tidal locking and great difference between day and night side, and close to flares. There may not be any water at all. But this is promising also in another respect: metallicity is about half that of the sun’s, and yet there are several planets. This bodes well for presence of (earthlike) planets in the milky way in general.
Also from the (incomparably useful) Extrasolar Planets Encyclopedia (EPE), from its Interactive Catalog, mass (in M-Jup) and semi-major axis (in AU) of all its 3 discovered planets (rounded off slightly): 0.048/0.04 , 0.015/0.07 , 0.026/0.25
What strikes me here is that rather large planets (resp. about 15, 5, 8 earth masses) can exist in stable (almost circular) orbits so close together, all well within the ‘orbit of Mercury’ (0.4 AU), which makes me believe that they originated in situ and are not the result of inward migration. This also bodes well.
Because of the likely correlation of planetary presence/mass with metallicity (and stellar mass?), see Correlation Diagrams of EPE, I am inclined to think that these three are its ‘giant planets’, i.e. that metal-poor stars have ‘mini-giants’ and that in the case of small stars these are also in close stable orbits. The situation is rather similar for other M-class dwarfs: Gl 876 (though one of its 3 planets is a real giant), GJ 674, GJ 436, and to a lesser extent GJ 849 (giant planet inbetween Saturn and Jupiter in ‘asteroid-belt-like’ orbit, still rather close, metallicity ?). So if this holds true low-metallicity M-stars would have mini-giants in very close orbit. Again, this may bode well.
What about medium/high metallicity M-stars? ‘Normal’ planetary systems with small rocky planets in close orbit and gas giants on the outside, or giant planets in close orbit? The first would again bode well.
Well, just some wanderings (wonderings?), as for now I am still betting on the sunlike stars (cooler F through G to hotter K), but who knows?
Hi dijactin
The Greg Benford novel visited two planets – Isis and Pocks. Isis was the tidelocked planet with a long river ringing the day/night border. Isis was in orbit around Lalande 21185. Pocks had the deep-sea, under a layer of ice like Europa, and was in orbit around Ross 128 – 6.5 light years from Lalande 21185, and 10.9 light years from Sol.
The deep ocean and eye-like island sounds kind of mixed up between Isis and Pocks – BUT it’s possible for a planet to preserve a “fossil bulge” and be football shaped like Larry Niven’s fictional Jinx (which orbits a gas giant around Sirius) and the recently discovered dwarf planet 2003 EL61. Thus two gigantic “islands” could exist as each other’s Antipodes, and a deep ocean/atmosphere could separate them. Would be a cool story locale, so hopefully you remember the novel. The different ice phases don’t kick in for thousands of atmospheres of pressure so it’d be a DEEP ocean.
Using 5 Earth masses and 50% larger than Earth diameter metrics plus crude high school physics, I get F=(GmM)/r*r = 5/(3/2)*(3/2) = 2.2 Gs
Not a fun place to visit.
I’d read elsewhere (forget) that 4+ Earth mass planets might have an oversupply of water making them oceanic worlds with no land. Since we know so little about real planetary formation, especially around different types of stars, that’s got to be very speculative.
The National Geographic Channel Special Extraterrestrial
depicted two possibly habitable exoworlds. The first one
circled a red dwarf. The planet was tidally locked – the
hemisphere away from the star was perpetually frozen,
while on the sunlit side a huge hurricane dominated the
center of that hemisphere for ages. It was in the sunlight
side areas outside the hurricane where the life existed.
http://www3.nationalgeographic.com/channel/extraterrestrial/
So there are two predictions for such planets around red dwarfs – in situ formation which predicts very dry planets, or migration which predicts ocean worlds. In addition it could have gone runaway greenhouse – it is quite close to the inner border of the HZ – especially on an ocean world where plentiful water vapour (very good greenhouse gas) would be produced. So if it is an ocean world it might be very steamy! Of course, having a tidally locked situation with a massive cold sink on the darkside might help the situation somewhat.
If the planet has less volatiles, it would have thinner atmosphere and less greenhouse heating. This might avoid runaway greenhouse, so small bodies of water might be able to survive – but if it is tidally locked, the water might all end up in the darkside ice cap.
@andy: all this seems to suggest that the main (only?) chance for a planet around a red dwarf (M-class) to bear life is if it originated further away with abundant water and dense but not too dense atmosphere, and migrated inward into a stable (very) close orbit.
Does not sound very promising.
On the positive side: a very water-rich, i.e. deep-ocean covered world, might have a strong heat-buffering and heat-spreading capacity (not just though atmospheric but also oceanic flows).
I suspect this planet would have an excess of water and atmosphere, compared to the Earth. It might actually be a pretty muggy and warm place, especially considering the excess geothermal heating caused by having ~5x as many radionuclides in its core but only 2.25x as much surface area to radiate heat from. The chances of life on this planet, assuming our assumptions are correct, of course, are tantalizingly high.
I reckon this planet is going to be a mighty unpleasant place – the equilibrium temperature with Venus albedo is 0 degrees C. The equilibrium temperature for Venus is -10 degrees C. Greenhouse effect could be ferocious.
To receive a similar amount of energy from Gliese 581 as Earth, a planet would have to be located at around 0.14 AU, which is further out than Gliese 581 c at 0.073 AU.
On the other hand, the habitable zone may extend out to 0.2-0.3 AU, which would put the third planet (of around 8 Earth masses) in the HZ, but near the outer edge. So maybe Gliese 581 does have a habitable planet, but because of the effects of greenhouse warming, it is the third planet, not the second.
In an optimistic picture, the Gliese 581 system may be a system of three ocean worlds – the innermost planet would have a supercritical ocean, the middle planet may have one that is near boiling point or perhaps supercritical, and the third planet a more normal environment. Interestingly enough, if the planet has sufficient water to form a layer of high pressure ice between the ocean and the core, photodissociation of water vapour in the atmosphere would lead to a buildup of oxygen in the atmosphere. This could have implications for the detection of biomarkers on the planets in this system.
Thanks Paul for providing a deeper view about this! (I was getting anxious as the only other person talking about this was asking for someone in the astronomy community to comment on this quick!)
The tidally locked item may present a problem for the world, but this does open up the possibility for habitable planets around red dwarfs.
PS
If we are not alone in our galaxy, I wonder if other inhabitants will find us having a yellow star odd instead of having a red one?
Darnell, that’s a very good point. 80 of the nearest 100 stars are red dwarfs. Yellow G-class stars like our Sun may indeed represent a small percentage of planet-bearing stars, there being so many fewer of them in the galaxy.
That’s why ETI aren’t contacting us – they all live around red
dwarf stars and think yellow ones are not compatible with
life-bearing planets. After all, yellow dwarf suns only last a
few billion years compared to red dwarfs. Hardly enough
time for anything really intelligent to develop.
ljk has a good point about ETI around red dwarfs…
And bring on the Kepler mission! Suspected detection of 100’s of terrestrial planets!
Maybe this will be the spark to light the fire and get us SERIOUSLY siphoning off some ISS money and planning the TPF and TPI?
Honestly, with all due respect: if an alien lifeform is truly intelligent, I don’t expect that they will limit themselves to red dwarfs.
And then again, what does abundance alone mean? M-stars may be very abundant, but the really interesting issues are chance/abundance of terrestrial planets and chance that such a planet is situated in the habitable zone. Since the HZ of M-dwarfs is so narrow, the overall statistics may not be as favourable as abundance alone suggests.
Hi All
Stellar lifetimes are similar in scale to the current age of the Universe and red dwarfs evolve a lot slower than G stars. In my mind it means that perhaps life’s evolution on planets of red dwarfs evolves slower too. I don’t mean the micro-level of species and genera, but major events like geophysical changes. The recent work on cosmic ray fluences over geological time – a cycle of 62 myr for extinctions suspiciously matching the Sun’s bobbing up-and-down with respect to the galactic plane – is one such process. Red dwarf planets will be deep in the magnetic fields of their stars, cocooned away from the lethal sleet from space. And the star’s fields will change slowly compared to the Sun and its kin.
Also water-loss will be a lot slower as the UV flux is lower for older red dwarfs that have finished their flare-star aeons. I suspect that Venus around a red dwarf would’ve retained its oceans for aeons longer than it did in the solar system – which was perhaps 2 aeons anyway. Even K stars probably have “Wet Greenhouse” Venus style planets for longer than the age of our solar system. Another factor is the fact that any asteroids or comets that venture close to the star will pack more punch – but there will be fewer of them.
But the new planet avoids all the planet-wrecking processes because it is so hefty. Over 5 Earth masses a planet would be pretty much immune to the atmospheric erosion, hydrogen loss, and geological arteriosclerosis that killed Mars and probably Venus. But with ~ 2 gee gravity and being warmer than Earth it may be a rather unpleasant planet.
We also assume it will be tide-locked but such computations assume a lot. With 5 Earth masses and 1.5 the radius the planet’s moment of inertia is over 11 times higher than Earth.
Go for it Seth !
—->>>
… Just because Gliese 581c is habitable does not mean that it is inhabited, but we do know its sun is an ancient star – in fact, it is one of the oldest stars in the galaxy, and extremely stable. If there is life, it has had many billions of years to evolve.
This makes this planet a prime target in the search for life. According to Seth Shostak, of the Search for Extraterrestrial Intelligence Institute in California, the Gliese system is now a prime target for a radio search. ‘We had actually looked at this system before but only for a few minutes. We heard nothing, but now we must look again.’
By 2020 at least one space telescope should be in orbit, with the capability of detecting signs of life on planets orbiting nearby stars. If oxygen or methane (tell-tale biological gases) are found in Gliese 581c’s atmosphere, this would be good circumstantial evidence for life.
—-
Read the Simon Laub / Jan Holst Jensen wager on
etmessage.blogspot.com
That’s why ETI aren’t contacting us – they all live around red
dwarf stars and think yellow ones are not compatible with
life-bearing planets.
There was a throw-away line in the late Hal Clement’s SF novel ‘Still River’, in which the aliens were described as badly shocked when humans showed up. The aliens, mostly from planets around red dwarfs, and with a wide variety of biochemistries, had assumed G type stars couldn’t have planets that would support life.
yes all,the discovery of this earth like planet is indeed very big news! i sincerely wonder how all of this will shake out! also,i am glad that it is 20.5 light years away and not 2500 or something! 20.5 seems much more “doable” even if only by an unmanned probe.and then…not for a bit. unless we find out some really really interesting news and a MAJOR effort is undertaken. for my part i predicted that in a situation like this people would suddenly turn around and demand a stronger space program in their rush to go there!! but as i stated above we first have to see how everything shakes out.ALOT of questions yet to be answered! respectfully to all your friend george ps forgive me if i overlooked anything obvious in my excitment over this news! it is indeed a biggie! thank you g
Ronald’s right — we haven’t blinded ourselves to the possibility of life around stars unlike our own, so why would aliens do so? We used to think life around red dwarfs was unlikely, but that was when we were relying more on speculation, and we changed our minds when better evidence showed otherwise.
I am not very science talk savy to start off with! I have a couple of questions that maybe someone can answer for me. What does TPF, TPI and Tide-locked mean. These terms were used throughout the replies and I am curious to find out what they mean. Oh and yes, this news about 581 c is indeed life changing for many people. I cant wait until they decide on what the next step will be from here.
Thanks,
Orlando
Orlando, nice to have you with us. TPF stands for Terrestrial Planet Finder, which is an umbrella term for a mission that NASA has been looking at for a long time using various technologies. The goal is to get actual images of terrestrial-type planets around other stars. Tidal-locking means the mechanism by which a planet very close to its star becomes slowed in its rotation until it presents the same face to the star at all times. Planets like Gliese 581 c are close enough to their star that they are probably locked in this way. That presents problems for habitability, as you would imagine, but some studies have suggested that a dense enough atmosphere might make it possible for stable, warm and habitable areas to exist on the day side even if the night side is quite cold. TPI is a reference to using interferometry — putting multiple telescopes on the same target so that the effect is of a much larger single instrument — to look at extrasolar planets from space. Instruments like these could pool their resources to get images that would be available in no other way.
Nice… Now we have to built an engine that speeds so fast , light speed, to rich the star and her planetary system. I’m also imased of what we are capable of as human race in the field of technology and discovering a lot of things in the space but no body is asking, HOW DO WE GET THERE?
I cant belive it
Andrei has a point. Think back in history when man concluded we would never travel faster than the speed of sound. My friend, that sound barrier has been broken. Einstein says nothing can travel faster than the speed of light….well then how the heck do we get to these places? 20.5 light years away….I don’t know about all of you — but that’s annoying! All of us sitting here may never (highly probable) — will never be able to see extraterrestrial beings. We will never see another planet — I say that’s not fair. Does anyone have any articles or sites that speak (scientifically and not fictionally) about interstellar space travel? I don’t think that “speed” is going to solve our problems — even traveling at the speed of light we would need to know the exact calculations to start slowing down – but if you slow down it over extends the time it takes to get there. ARGH! So frustrated. It keeps coming to mind that scientists are working on teleportation — I read an article about them teleporting Adams recently………….maybe it will be the only way because I don’t think speed is an option. I think we should resort to science fiction to come up with technology — think about CONTACT.
For those looking for the paper and some other info (if I missed the posting here in the activity, have a read:
http://www.eso.org/outreach/press-rel/pr-2007/pr-22-07.html
http://obswww.unige.ch/~udry/udry_preprint.pdf
http://planetquest.jpl.nasa.gov/index.cfm
Best,
Paul
Paul Shankland
GEMSS USNO
Is tide locking inevitable? What if it has a substantial moon, as the Earth has? Couldn’t that get into resonance, and avoid tide lock?
I don’t think the “planet locked to moon” idea is likely. The Hill radius of the planet (the region in which tidal forces from the planet dominate over solar ones) is going to be quite small: at around 280,000 km for the minimum planetary mass, it is smaller than the Earth-moon distance. If the planet is smaller (e.g. if a substantial fraction of the observed mass is in the form of a satellite), the Hill radius decreases as m^(1/3). Worse, satellites are only long-term stable out to about a third of this distance, or 92,000 km.
The orbital evolution of large moons goes faster than that of small moons. Therefore large moons are probably not going to survive long – and they don’t have to migrate particularly far before they reach outermost stable orbit, or the Roche limit (at which tidal forces would rip the moon apart – for minimum mass planet, and density the same as Earth, this works out as 27,000 km). I’d guess that if Gliese 581 c does have moons, they are going to be asteroid-size.
While planets on eccentric orbits can get captured into higher-order resonances, as far as I know the observed orbital eccentricity may not be high enough to put the planet in a Mercury-style 3:2 spin resonance either (in fact, Mercury’s current orbit probably isn’t eccentric enough – but Mercury apparently spends some of its time at much higher eccentricity than it is now, enabling capture into the resonance).
All what you see in the vast universe is the power of the Lord Jesus Christ who
made this universe. I am sure there are worlds, outside our solar system, where people live. You can read in the book of Job in the old testament, that there was a day when the sons of God came to meet Him, and satan came also. This is the same angel, who was Lucifer. He sinned and fell. Those who will get to heaven when Jesus Christ comes, at the end of the world, will see in eternity the glory of God in space. Infact, we will visit those planets, which seem far away, but, at that time we will go there easily.
This is great news, although everyone seems weary to commit to the possibilities at this stage obviosly, it is still very exciting.
Don’t name it anything ‘earthly’. People, you’ve got to remember that this planet is TWICE THE SIZE of Earth, possibly collects more than our fair share of radiation, may NOT have a moon (which helps keep our orbit, rotation and biosphere tolerable)…and that atmosphere may not be the ideal one for carbon-based lifeforms (“Humans, Ensign Perez; us! – (McCoy, STAR TREK: THE MOTION PICTURE). So don’t be too quick to compare it to WHAT WE ARE FAMILIAR WITH!
I was wondering what you’d name a planet like this if it did turn out to be habitable. I was thinking maybe one of the Roman or Greek gods to keep with our current planet naming theme.
If the planet is inhabitable, perhaps we should ask the natives
what they call their planet before we go labeling it for them.
Names for the earth-like planet:
Bloatotopia
Alienia
Bigrock
Telescopotubby
Poofy the Sphere
Whew Earth
Hopeuria
Heavenoidia
Quick Stop #2,954,876 (Last Gas Before Andromeda)
Thisballforrent
Cloud Nine Zillion
Pluto’s Mom (she’s pissed about you know what)
Asterillion
Appolocopulus
San Fran Cosco
Walmarlionia
Plymouth Plus
Gigantojupitoid
Magnificana
Clean Fill Wanted
Edg
Heh, I’d suggest Sisyphus as a name for a super-Earth in the habitable zone (which Gliese 581 c is certainly not). The mythological character was condemned to push a giant boulder up a hill for all eternity, which I think would describe the feeling of being in the high gravity of a super-Earth quite well.
Then again, until we know more about the planet besides minimum mass and a few orbital elements, I think we should hold off on giving names.