back to article Stargazers spy super-Earth waterworld

Astronomers from the Harvard-Smithsonian Center for Astrophysics (CfA) say they've spotted a super-Earth waterworld orbiting a red type M star some 40 lightyears from Earth. Artist's impression of GJ1214b. Graphic: David A. Aguilar, CfA The body - dubbed GJ1214b - is circling dim host star GJ1214 every 38 hours at a distance …

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Welcome

Pressure at sea level?

Must be quite high to be a water world with an ambient temperature 100 degrees above the boiling point of water at one atmosphere!

I for one welcome our web-footed, gill-sporting sauna-loving overlords.

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RPF
Pint

200°C water-world?

Shouldn't that be a "Steam-World" then. at least on the surface?

The biggest distillery yet known to man, perhaps?

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I for one...

I, for one, welcome our new ... er .. steamed fish overlords.

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Virgin

Virgin's new holiday resort after you spent £120,00 on going to space with Virgin, you'll get a voucher for this new resort.

Sounds nice although i would suggest only putting notes in your pockets, no coins.

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Alien

Everybody!

It's cold outside, there's no kind of atmosphere...

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Boffin

Wot, no Ice-9?

Kurt would be so disappointed...

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Waterworld

I think that in the interests of science, we should send Kevin Kostner there anyway.

While I realise there is a slight possibility of him surviving the ordeal, it is nonetheless a risk worth taking.

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Troll

May I be the first to say...

No, it's NOT too hot for Kevin Costner.

5 words of justification: Coffee Grinder Dances With Wolves

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Ice VII...?

After the debacle that was Ice VIsta, this Ice 7 had better be good.

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Excellent environment...

...for cooking vegetables. A natural pressure cooker. Pity it's so far away, everything is going to get cold on the way back.

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Bronze badge
Boffin

Bar on another planet

"we're assuming GJ1214b has a surface pressure greater than 16 Bar, at which water boils at 200°C"

Why assume, it's right there in the quote - "20,000 times Earth's sea-level atmosphere" or to put another way, 20,000 bar. One bar is defined as one earth atmosphere so the maths is easy.

In water pressure rises 1 bar for each 10 metres depth, so for 20,000 bar you would need to be 200km underwater on earth, or very nearly 200km deep assuming your 16 bar.

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Boffin

But does pressure increse faster in high G?

Given that the planet has a gravity 2.7x ours, would pressure in the water go up 2.7 bar per 10 meters? Or would it go up 16 bar (one atmosphere) every 10 meters?

I think my maths show that if the former is the case then the Ice VII would occur at ~74km, which is almost believable given a diameter 6.5x that of earth. Our average ocean depth is between 3 and 4km with trenches and the like going as deep as 10-11km, a simple multiplication would put it that this one may have trenches nearly that deep. (11*6.5=71.5)

At 16 bar per 10m, Ice VII would form at 12.5km. which would be relatively shallow.

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Silver badge

Surface gravity = 0.9g

Being 6.5 / (2.7 ^ 2) - the result of the density being so much lower, hence the assumption that it's mostly water.

So quite comfortable, then (if a tad on the warm side).

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Alert

Bar on another planet

@Lusty: Why assume, it's right there in the quote

That's not referring to the SURFACE pressure of the planet, but deep in the interior.

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Paris Hilton

That's hot!

'nuff said.

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Paris Hilton

dim host star

'nuff said.

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Thumb Up

16 bar, hot water...

Coffee-world!

Hazaaaaa!

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Happy

Would be a good spot to refuel from

Most of the planned ships required to reach it are mass drivers , so I can see it getting annexed by someone a few hundred years into the future

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Alien

Looks just like

Looks just like Floston Paradise, except someone left the oven on...

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FAIL

El Reg standard units please.

How else do you expect us to draw meaningful comparisons, for example, how many Olympic size swimming pools would this planet fill?

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Coat

Squire - That title enough?

"how many Olympic size swimming pools would this planet fill?"

I'd estimate... all of them!

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Bronze badge
Welcome

Superb, but here's the IT angle

As its a red dwarf system, one can assume its very old. Possibly any life forms that have evolved there have been and gone long before now. Or perhaps they are among us?

More likely is there won't be very many heavy elements in the system. Perhaps only up to Oxygen.

I for one welcome our new nebulous overlords!!

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Alien

Exo life?

If sea level temp is 'only' 200C and 16 atmospheres, that's actually not too far from the tolerances of known extremophile organisms.

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Typical grant sucking exaggerated theories

Stating this all is fact is totally laughable. I enjoy learning about real science findings, but presently, it is all they can do to even determine that maybe there is a planet around a star other than our own by its wobble. Composition of distant objects is only theoretical, even less their gravitational levels. They have no way whatsoever of accurately determining what they are actually made of on their surface (only reflected light wavelengths, which are far from the final word and very crude, they are only a preliminary tool to start from) even less what the supposed planet's core is made of, which is invisible to their instruments, which would affect gravity levels tremendously. As the composition of atmosphere is entirely uncertain as well, temperature levels of this all but invisible "planet" is truly impossible. But all theories are welcome to be reported as fact! After all, no one has the ability to refute them since we can not even get past 2/3 of our own solar system with a lander probe! We are even somewhat in the dark as to the full nature of the composition of our own planets core is, being unable to extract any matter that deep to study hands-on. Even that is theoretical, although the theories are founded on much more study and physical data and may be correct... or not.

Those beautiful multi colored photos of nebulas from Hubble you have seen... were not taken in color, but via time exposed infrared black and white and then colorized after the fact. Additionally, the color is artificially enhanced and often significantly inaccurate even according to what they know the general color to be in some cases. Sometimes with known-red nebulas, they multi color them to make them look prettier. All to stimulate interest - for popular...and financial grant attraction reasons, I suppose. But accurate they aren't - nor is it scientifically accurate to present them as how they really look like at least color-wise. The trend is all too common.

Inferring that the technology exists to determine the makeup, gravity, atmosphere, and temperature of a distant all-but-invisible planet is just like the 5 minute DNA tests on CSI - the technology doesn't exist and therefore the results are fabricated as well. Why they cannot stick to what is known within our technological capabilities (which is often exciting of itself, although not as flashy) and mark theories beyond that as what they are is troubling. But perhaps telling people that they have noticed a wobble in a distant star and that there seems at time to be a blue wavelength light cropping up which might mean a planet that has water, doesn't grab grant funding the same way. Why they don't go all the way and tell us its likely that it is similar to the planet in Avatar, making a pop culture link, I don't understand.

But the vegetable pressure cooker promotional idea might win some interest with the low-carb crowd. That does mean that the planet is likely inhabited entirely by healthy aliens with low cholesterol levels, doesn't it? Perhaps they should add that to the report.

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Boffin

Actually

you might want to check some facts:

- The period of the wobble combined with the velocity profile give a good estimate of mass (masses of red dwarfs can be estimated quite well from spectral type) and the distance to the star's surface.

- The light profile gives a good indication of diameter.

- Therefore, assuming a spherical rather than e.g. tetrahedral planet (fair enough as assumptions go) you can arrive at a density.

- Density gives you some idea of composition, assuming common substances such as found in our solar system. Somewhat nebulous, but you can rule out some options such as a completely rocky world with a large iron core, or a gas giant.

- Spectroscopy from space-born telescopes could possibly be used to get a better fix on atmospheric composition. I am a bit worried about the small distance to the star, based on the orbital data, but it might be possible.

- Temperature can be estimated from the distance to the star's surface, and some basic thermodynamics: equating incident radiation from the star, and emitted black-body radiation from the planet. The latter can eb confounded by the unknown albedo of the planet, but a plausible temperature range can be deduced.

Bottom line: there seems to be an interesting object there, certainly worth having a peek at by spectroscopic means.

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Not necessarily ice VII or liquid water

With an atmospheric pressure of 20,000 bar (as one commentor notes below), and temperatures around 200 deg C (merely an approximation provided in the article), much of the water might exist as a supercritical fluid - neither liquid, gas nor solid - neither fish nor fowl. The supercritical point for water is 374 deg C at 218 bar. As such, its physical properties overall would be significantly different from liquid water: non-compressible, lipophilic, diffusion rates similar to a gas, and molecular collision rates similar to a liquid. And perhaps the real picture is a combination of multiple phases co-existing.

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E 2

Let's go!

Massive amount of water, solves one of the bigger problems wrt colonization. Let us go forth and colonize that solar system!

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Thumb Down

Big speach above

Thats all very intresting, well actually no it wasnt, infact, that is the problem with your idea, if we didnt add a bit of zest in to the great unknown then it would be completely boring. If you want to get in to it, the basic ideas of physics isnt an exact universal science, because we simply dont know, much of it relies on time, which as some folk believe doesnt exist anyway, So lets stop all creative thought because in actual fact, we know bugger all about anything.

Seriously tho, if we didnt make up some bits people wouldnt be intrested in it, then the money would stop and we wouldnt be getting anywhere with finding out whats what in our lovely universe.

As for colour of photos, by applying filters before shots are taken you can get a rough idea what colour it is, take for example some of the outer planets, before we had probes taking snaps we had a fair idea of what they looked like, dispite on earth them all looking more or less dirty white, exception of mars that is which has a orange tinge on dirty white.

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Silver badge

Official request

Could we please reserve the term "Earth-like" to exoplanets that actually resemble Earth ?

A planet that is over 6 times Earth's mass, that circles its sun every day and half and has a surface temp of over 200°C is NOT Earth-like.

Being Earth-like should not be due to the simple virtue of being round and smaller than Jupiter.

I want the term Earth-like to designate planets that actually resemble Earth : something that is Earth-sized to within 25% of Earth's mass, that has an orbit of somewhere around 350 days and a surface temperature average of anywhere from 12°C to 20°C. That is Earth-like.

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Heart

Spa World

I'd like to volunteer to go to this planet with a ship full of lovely young ladies in tight white uniforms (hopefully they'll get 'bored' on the way) and set upThe Spa in the Middle of the Universe.

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Alien

Want to know where habitable planets are?

<--- Eh... Ask him?

Or the scientologists?

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Alien

Theories as facts

>Stating this all is fact is totally laughable. I enjoy learning about real science findings, but presently, it is all they can do to even determine that maybe there is a planet around a star other than our own by its wobble.<

My favourite 2 are humans descended from monkeys, despite still having a missing link between the two, and the big bang theory (not the comedy which I love) but the lovely scientist creation myth which has as much scientific evidence as the biblical myth.

Now, I'm not saying we didn't evolve from monkeys, or that there wasn't nothing, which then exploded (thanks Terry Pratchet), but please stop espousing these things as facts. They are theories which are currently in vogue much like the earlier 'facts' that the planet was flat, that the universe revolved around us and that God looked much like us, but with a white flowing beard.

Scientists still can't match up quantum physics with relativity, the two theories are mutually exclusive. The singularity in a black hole makes the cleverest scientist break down and cry like a little girl.

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Boffin

Ever read Alan Sokal's dictum?

"He who thinks gravity is a social construct may try this outside my office window (I work on the 20th floor)"

Every scientific model of reality is just that, a theory, which remains in place until replaced by a better one. The only facts scientists deal with are measured data, which themselves are suspect in their own way (noise, instrumental drift, etc). Some theories become very hard to falsify: the second law of thermodynamics being top candidate, evolutionary theory being another. This is because they follow from very simple assumptions. In the first case the assumption is simply that the world is made up of very many small objects behaving more-or-less randomly, which makes it easy to bet what the average outcome of any event involving them is. In the case of evolution all we need to assume is that there is:

(i) a source of variation within a species

(ii) that this variation results in variable *likelihood* of survival and procreation

(iii) that these variations are heriditary (need not be genetic, by the way!)

These are the only ingredients needed to obtain evolution. We know there is interindividual variation within a species (just look around you), we know many of these variations are heriditary, and we know some variations are beneficial (e.g. resistance to disease). It then becomes very hard not to have evolution. This does not mean we know all the ins-and-outs of evolution, but the basic principle holds well.

Regarding the big bang: see Hubbles work on redshift vs. distance. The simplest explanation is that things used to be closer together. I think this is more evidence than biblical myth, especially because of the vast number of galaxies measured. Of course, there are many details which are poorly understood (which keeps my colleagues in the Astronomy dept happy), and many variants of the big bang theory exist. If a better theory comes along, all the Big Bang theories will be in the scrap-heap, but it has been the best family of theories on the block for quite a while.

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Alien

Life?

If the average temperature is 200C at the surface, it may be below 122 C at the poles - and there are terrestrial life-forms which can reproduce at that temperature, though they are single-celled.

On Earth these extreme thermophiles only exist in confined spaces like volcanic vents, but if there is enough room, as there would be on a planet, there doesn't seem to be any reason why multi-celled organisms couldn't exist.

Chemistry and perhaps evolution would go faster than on Earth, so it's entirely possible that there is a highly developed ecology there, and perhaps even a civilisation.

Their spaceships might be filled with water at 122C and high pressure - but Earth conditions wouldn't suit them, so they may not have bothered to visit us. They may even think life at 20C is impossible!

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Earth-Like

I think we should start using planet classifications like in Star Trek instead of using Earth-Like.

Earth = M Class - sutible for human life.

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