The newly discovered planet is depicted in this artist's conception, showing the host star as part of a triple-star system. The diagram below shows the orbits of the detected planets around the host star in relation to the habitable zone. Images courtesy of Guillem Anglada-Escudé, Carnegie Institution.

Potential ‘Goldilocks’ Planet Found

Article Updated: 24 Dec , 2015

by

[/caption]

A new-found planet is in a ‘just-right’ location around its star where liquid water could possibly exist on the planet’s surface. A team of international astronomers have discovered a potentially habitable super-Earth orbiting a nearby star in a habitable zone, where it isn’t too hot or too cold for liquid water to exist. The planet, GJ 667Cc, has an orbital period of about 28 days and with a mass about 4.5 times that of the Earth. The star that it orbits is quite interesting. It is an M-class dwarf star and is a member of a triple star system and appears to be quite different from our Sun, relatively lacking in metallic elements.

The team said this discovery demonstrates that habitable planets could form in a greater variety of environments than previously believed.

“This was expected to be a rather unlikely star to host planets,” said Steven Vogt from UC Santa Cruz, one of the scientists involved in the discovery. “Yet there they are, around a very nearby, metal-poor example of the most common type of star in our galaxy. The detection of this planet, this nearby and this soon, implies that our galaxy must be teeming with billions of potentially habitable rocky planets.”

“This planet is the new best candidate to support liquid water and, perhaps, life as we know it,” said Guillem Anglada-Escudé, from the University of Gottingen in Germany. He was with the Carnegie Institute for Science when the planet was first discovered.

The planet orbits quite close to its parent star at 0.12 astronomical units, which is much closer than Mercury to the Sun. However, the Planetary Habitability Laboratory says the star is much dimmer and provides enough energy for the planet to possibly maintain similar terrestrial temperatures. There’s a caveat, though, that astronomers aren’t sure what the planet’s composition is, because they have not been able to measure its size; therefore, it could be a either a rocky or a gas planet. I would need to have a radius between about 1.7 and 2.2 Earth radii to be a rocky world.

The team used public data from the European Southern Observatory combined with observations from the Keck Observatory in Hawaii and the new Carnegie Planet Finder Spectrograph at the Magellan II Telescope in Chile. To follow up and verify the findings, the team used the radial velocity method to measures the small wobbles in the star’s motion caused by the gravitational tug of a planet.

“With the advent of a new generation of instruments, researchers will be able to survey many M dwarf stars for similar planets and eventually look for spectroscopic signatures of life in one of these worlds,” said Anglada-Escudé.

The star, GJ 667C is 22 light years away. It has much lower abundance of elements heavier than helium, such as iron, carbon, and silicon, as does our Sun. The other two stars (GJ 667A and B) are a pair of orange K dwarfs, with a concentration of heavy elements only 25% that of our Sun’s. Such elements are the building blocks of terrestrial planets so it was thought to be unusual for metal-depleted star systems to have an abundance of low mass planets.

Diagram of the planets orbiting the star GJ 667C. Credit: UC Santa Cruz

GJ 667C had previously been observed to have another super-Earth (GJ 667Cb) with a period of 7.2 days, although this finding was never published. This orbit is too tight, and thus hot, to support life. The new study started with the aim of obtaining the orbital parameters of this super-Earth, and came to find an additional planet.

The new planet receives 90% of the light that Earth receives. However, because most of its incoming light is in the infrared, a higher percentage of this incoming energy should be absorbed by the planet. When both these effects are taken into account, the planet is expected to absorb about the same amount of energy from its star that the Earth absorbs from the Sun. This would allow surface temperatures similar to Earth and perhaps liquid water, but this extreme cannot be confirmed without further information on the planet’s atmosphere.

The team said there is a possibility of other planets in the system, potentially a gas-giant planet and an additional super-Earth with an orbital period of 75 days. However, further observations are needed to confirm these two possibilities.

This is the fourth potentially habitiable extrasolar planet. Three were found in 2011: Gliese 581d, which scientists say is likely a rocky world about 20 ight-years away; HD 85512 b, another planet orbiting in a habitable zone is about 36 light-years away from Earth; and Kepler 22b, about 600 light-years away. Vogt was involved in the discovery of another planet in 2010 (Gliese 581g) in which he said the “chances of life on this planet are 100%,” but other astronomers have cast doubt on whether that planet even exists.

Papers:
The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample, and A planetary system around the nearby M dwarf GJ 667C with at least one super-Earth in its habitable zone (will add link when it becomes available)

Sources: UC Santa Cruz, Carnegie Institute for Science, Planetary Habitability Laboratory

,



Sort by:   newest | oldest | most voted
henk
Member
henk
February 2, 2012 6:21 PM

nice, but i think that kepler 22b is a far better candidate for life. We do not really now if a red dwarf is good to support life. maby we should first investigate that.

Anonymous
Guest
Anonymous
February 2, 2012 11:47 PM

The only problem is that it is a flare star, the planet needs a powerful magnetic field in order to keep its magnetic field intact. It’s larger than the Earth and the orbital period should not be so long as to stop a dynamo effect from occurring.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 2, 2012 7:20 PM
Keep them coming! The planet is a bit on the heavy side, so it is unclear if it is a neptune or a terrestrial. Also it has to have a tad light atmosphere to be habitable. At the modeled Earth atmosphere pressure it would not protect as much against the more serious CMEs a young M star tend to give. It would be interesting to know the age of the star, but I can’t find it. I’m not sure why they speculate in that metal-poor star has fewer planets. As I remember it smaller stars on average has more terrestrials but metal-poor stars are believed to have less jupiters. Another speculation often heard is that M stars, which… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
February 2, 2012 7:44 PM
If the planet has a composition similar to Earth its surface gravity would be around 1.65g. If the radius is 1.7R_earth then is surface gravity is 1.55g and for 2.2R_earth it surface gravity would be .93g. This planet is just within the range I think which could be explored with interstellar probes. A photon sail, driven by a collimated beam of solar light directed by a large Fresnel lens, could reach ? = 1.5, or with ? = 1/sqrt{1 – (v/c)^2} a velocity v ~ .75c, which might reach the star in about 40 years and transmit data back in 22 years. That means people starting the project might actually live to see data returned. This planet is… Read more »
Anonymous
Guest
Anonymous
February 2, 2012 11:27 PM

From the diagram it looks like GJ 667 Cc is in the region of the habitable zone where the Earth is located. That might make it habitable for many components of the terrestrial biosphere. Looks like a good candidate for settlement, it’s only 22.1 ly away.

Lawrence B. Crowell
Member
Lawrence B. Crowell
February 3, 2012 12:38 AM
A mission to send a probe to GJ 66 would be a huge endeavor. I don’t think we will have the ability to send a robotic spacecraft there until the second half of this century at the earliest. Honestly I suspect interstellar probes may not be sent until the 22nd century, and this assumes our species or civilization has not sh*t canned itself by various possible means. Sending human travelers to other stars would be orders of magnitude larger in scale and complexity. We have found an array of planets in this galactic neighborhood; some which we know are very different from anything in our solar system. I read a while back about a hot rocky planet orbiting… Read more »
Anonymous
Guest
Anonymous
February 3, 2012 5:51 AM
I agree with you. But what I’m saying is that it would be relatively easier to send a probe to this planet than to, say, Kepler-22b 600 light-years away. As for living there, I’m pretty sure that you could live on GJ 667 Cc, but it would be incredibly difficult. Not that you’d die early or anything, you’d just need to be in good physical shape and willing to withstand stress. People would anyway probably do less physical activity as a result of being on that planet, if we ever colonized it. But in any event, obese people are able to stand on Earth. It would require more exertion like that, but an able-bodied colonist should be able… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 3, 2012 10:55 PM

Some of those effects would be the first years, the skeleton would remodel et cetera, as well as first generations.

Unless development is seriously affected (can or has been tested in centrifuges here I would bet, at least on insects), some of those effects may go away within the first generation or two. The rest would be under heavy selection, and who knows how much will go away.

Anonymous
Guest
Anonymous
February 4, 2012 6:12 AM

I’d have to contest this idea that the planet makes a decent candidate for colonization. Remember it is tidally locked. This causes huge imbalances in temperature between the star facing side and it’s counterpart.

Depending on how thick the atmosphere is, you could be up against some pretty ferocious planetary winds. It’s quite possible these winds would make living on the surface impossible (or reaching it for that matter).

FleetFoot
Member
FleetFoot
February 3, 2012 10:04 PM

Laying aside the Fresnel lens possibility, I think a raw sail can still achieve better than 2% of the speed of light (I’d love to get your book some day to see if my calculations are anywhere near yours – if the price comes down) and the main advantage then is that slowing down uses the symmetrical process of course. Looking at what Rice University is doing with nano- vehicles, self maintenance and self replication may be possible before the end of this century. Aluminium on a carbon nanotube and graphene structural frame could make a very high lightness sail.

http://www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=13528&SnID=1581437466

Julian Sloop
Guest
Julian Sloop
February 3, 2012 1:02 AM

What do you think about the possibility of life forming in liquid methane? All that talk about life possibly existing on Titan, couldn’t we monitor the flux in Titan’s atmospheric composition and determine the answer to that question?

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 3, 2012 10:48 PM

That is exactly how the speculations got amplified, the surface has a deficit of hydrogen, and a surplus of acetylene IIRC, which can’t yet be explained by astrophysical models. Hydrogen to acetylene metabolism could be one explanation, or something else interesting associated with the surface.

Julian Sloop
Guest
Julian Sloop
February 3, 2012 11:31 PM

I find this amazing. How wild would it be if humanity discovered such a life form! Could you imagine the possible uses for such organisms? I really hope that America decides to stop half-assing space exploration, if not the scientific community could soon be moving to china, lol.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 4, 2012 12:55 PM
“Possibilities for methanogenic life in liquid methane on the surface of Titan”, McKay et al. (Icarus 2005, so not the latest on the atmosphere measurements and modeling.) “If bacteria are consuming complex hydrocarbons at the surface of Titan, the observable effects might include: complete consumption of C2H2 at the surface, reduction in C2H6 and organic solids at the surface compared to the accumulation expected from photolysis alone, and a sink of hydrogen at the surface creating a gradient in the hydrogen mixing ratio with altitude. All of these effects may be detected and measured by the Huygens probe.” “What is Consuming Hydrogen and Acetylene on Titan?“: “Two new papers based on data from NASA’s Cassini spacecraft scrutinize the… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
February 4, 2012 3:31 AM

There might be some complex chemistry. However, at those very cold temperatures ~ -170C on Titan the rate chemical activity takes place is much lower. There might be complex self-adaptive chemical processes, but they might not be exactly what we call life.

LC

Kawarthajon
Member
Kawarthajon
February 3, 2012 4:20 AM

Yes, but it might take hundreds (thousands?) of years for humans to get to the point where we can build such a lens (“large” is a bit of an understatement) , if we don’t kill ourselves in the mean time.

Lawrence B. Crowell
Member
Lawrence B. Crowell
February 4, 2012 4:01 AM

If you look up how a Fresnel lens work you see this does not have to be a huge thick lens of material. It would be more like a huge thing sheet.

LC

Kawarthajon
Member
Kawarthajon
February 7, 2012 7:29 PM

I have looked it up. I never said it would have to thick, I was just responding to your comment about it being a “large” Fresnel lens. It would have to cover a large area (again, an understatement) in order to focus enough of the light to make the spacecraft travel fast enough to be meaningful and we are very far away from the technology to be able to build such a lens, not to mention the economics of doing it. .

Gore Gogore
Guest
Gore Gogore
February 3, 2012 11:00 PM

I don`t believe in the capacity of a spaceship to gather data from a star system (like our solar system) while flying at 0.75c, nor photos. Also i don`t believe in our capacity to receive signal from a small spaceship 20 light years away.

Lawrence B. Crowell
Member
Lawrence B. Crowell
February 4, 2012 3:10 AM
The solar sail is a disk of reflecting nanometer thin material. There would of course be a mast assembly and so forth which holds a shape and anchors the spacecraft to it. The sail would have a radius of 10km or so. The Fresnel lens would be this material in a fine grained pattern similar to those old overhead projectors base. That is a Fresnel lens. This too would be huge. The craft would accelerate by photon pressure up to maximum velocity. When it gets close to its destination the collimated beam of light again reaches the sail, but now a small central disk detaches. These photons reflect off the main sail, now an annulus and reach the… Read more »
Anonymous
Guest
Anonymous
February 4, 2012 3:48 AM
I’ve heard and read about the solar sail concept before and it seems interesting, but 2 questions always come to mind. Firstly, will the craft be able to obtain enough light to reach maximum velocity while continuously moving away from it’s source (i.e. the Sun), and second, with such a delicate structure, what is to prevent the sail and craft from being damaged by things like interstellar dust and debris? Clearing the Oort cloud alone, with all it’s asteroids and rocks, would be difficult without some sort of “deflector” set up a la Star Trek. Then there’s the question of what lies beyond the Heliopause insofar as small or large obstructions is concerned. With 10km square of sail… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
February 4, 2012 4:03 AM

That is the point of the Fresnel lens optics. This collimates a beam onto the photon sail far out into space.

As for impact damage, the major concern is with the core spacecraft. The sail is just nanometer thin material. Any tiny piece of material will just pass right through. It would be best to select target stars which are not in line with the ecliptic to avoid much of this problem.

LC

Anonymous
Guest
Anonymous
February 4, 2012 4:17 AM

Small objects just passing through makes sense, but what about something larger? What kind of control systems will a spacecraft like this be able to have? Or is it more a “set it and forget it” deal? If a big piece of debris rips the sail, or somehow tangles the supports (ostensibly, in order to produce the maximum reflectivity, one has to assume there wouldn’t be a massive support system which would obscure the sail) will that render the craft useless? Again, really interesting concept. Just curious about it’s feasibility.

Anonymous
Guest
Anonymous
February 4, 2012 5:59 AM

In my understanding, there wouldn’t be any tangling or ripping. Any object would punch it’s way through, as their would be a huge speed difference between interstellar debris and the craft. Perhaps LC can elaborate on this.

Anonymous
Guest
Anonymous
February 5, 2012 12:54 AM

I guess what it ultimately comes down to is if there are any other more practical solutions feasible. Probably not until a new propultion system is designed, which may be tomorrow or a thousand years from now. Wouldn’t it be something if this world was inhabited, and with intelligent life? Imagine their surprise to see something obviously made on another coming careening through space toward their planet through the cosmos. Wouldn’t it be surreal if after all the UFO theories, movies, science fiction novels… If WE ended up being the visiting extra-terrestrials… Surreal

Anonymous
Guest
Anonymous
February 5, 2012 9:29 AM
It would be nice, but improbable given the current climate for large-scale scientific projects. LC’s Fresnel sail is probably the best method for obtaining relativistic speeds this century. It is better then Fusion Impulse, or Nuclear Pulse Propulsion – both of which are less efficient and require decades of development anyway. It is rather unlikely we will come across another HEI (human equivalent intelligence). By this I mean a intelligence similar to our own that adapts it’s environment through the use of tools. We can give a very rough estimate of this type of life form given our Keplar findings and extrapolating from our own Earth history. We have gone over this issue extensively in other postings. In… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
February 5, 2012 12:35 AM

Nothing is certain. If the photon sail craft crashes into a large enough of an object it could be destroyed. The central craft could suffer an impact, and even if the object were submillimeter in size the energy released would be equivalent to several pounds of explosives. If that just hits the sail the explosive energy just expends itself behind the path of the craft.

LC

Kawarthajon
Member
Kawarthajon
February 7, 2012 7:34 PM

There are materials being developed now that have self-healing properties. It would be awesome to have a self-healing solar sail.

FleetFoot
Member
FleetFoot
February 5, 2012 2:20 PM
The light falls off as the inverse square of distance so you need to get as close as possible to the Sun with a plain sail. That is temperature limited (assume a near black body rear side) but rotating the sail to grazing incidence (sail surface aligned with the limb of the Sun) can give a useful improvement. The Fresnel Lens approach means you create a very low divergence beam so can use much lower thrust for a longer time. It still becomes inverse square beyond the Rayleigh Distance though. To lose half the energy sending a beam to Alpha Centauri for slowing the sail would require a lens 50km in diameter using visible light. That size and… Read more »
Kawarthajon
Member
Kawarthajon
February 7, 2012 7:40 PM

Could you not use the focussed sunlight to power the systems on the spacecraft? Attach a solar panel to the solar sail and you have power. That sunlight would be very concentrated and would make the panels much more efficient than the ones currently deployed in space, although I guess the efficiency would decrease dramatically with time. Alternatively, you could use a thermal electric system, also using the concentrated sunlight. Maybe this would stand the test of time better than solar electric?

FleetFoot
Member
FleetFoot
February 10, 2012 4:32 PM
Yes it could but even then the power available would be quite small so it’s doubtful what use it would be. Sending signals back needs lots of power which would be more readily available from the target star if the craft were in range to make measurements. The spin method gives free energy (since the spin comes from the incident thrust) and doesn’t need any infrastructure at the sending end. Actually, I made an error in my calculations, the numbers I gave are for RF sources where a synthetic aperture antenna can produce a collimated beam. Lawrence’s optical Fresnel lens cannot do that because the Sun is an extended source. To create a well collimated beam, you have… Read more »
Eric E
Member
Eric E
February 2, 2012 10:36 PM

Goldilocks still doesn’t mean much =

Peter
Member
Peter
February 3, 2012 3:03 PM

Eric,
Yes it does.

Eric E
Member
Eric E
February 3, 2012 10:27 PM

What can it actually tell us though? I’ve seldom heard an astrobiologist speak in those kind of terms. Mars and Venus are ‘Goldilocks’ planets too, they remind us.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 3, 2012 10:43 PM

I am not sure what you mean here. The astronomical program is quite clear cut and often presented.

– Kepler and others are surveying stars for exoplanets.

– From such surveys that one can design targeted missions for characterizing exoplanets.
This helps constrain models of planetary systems and their formation.

The similar astrobiological program is at least partway solidified.

– From exoplanet characterization one can hopefully find and characterize inhabited planets, with oxygen and nitrogen oxides in the atmosphere as biosphere indicators. This helps constrain models of biospheres and their formation (aka abiogenesis).

In as much as abiogenesis is a phenomena too large and too long to easily fit in a lab, nature can help us with finding out how life gets started.

Eric E
Member
Eric E
February 3, 2012 11:13 PM

I was suggesting that people may miss the point when they hear the term “goldilocks”. Given that so many variables play into our habitability, I believe that this term is giving some of the public a very narrow view of how scientists may characterize planets/moons.

Cheers
E

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 4, 2012 1:09 PM
Ah, yes, that is also very sensible. Actually I have seen “Goldilocks” mentioned as a description of the last refuge survival zone ~ 1 km down the crust that shows up in models of Late Heavy Bombardment survivability. Maybe also for the Galactic Habitable Zone? But it is populated by (religious or not) Rare Earthers, so is suspect as a propaganda tool. Which is the point really, what does it mean? That gets into the similar discussion on habitability measures, Earth analogs measures, et cetera. It is context dependent as these are relative measures based on a sensitivity idea – how much different can a planet be and still have a possibility of life? So you start out… Read more »
Peter
Member
Peter
February 5, 2012 2:46 PM
I appreciate “Goldilocks” for precisely what it means. No more, no less. It puts a planet in a POTENTIAL zone. The rest of the information is not available. We don’t know about the depth of atmosphere, whether or not there is a magnetosphere, or much else at all. Therefore, we widen the scope of the G-zone to accomodate oddball planets of extreme likelihoods and assuming liquid water is a necessity, give each star it’s halo of probability. Since having all the ingredients for life AWKI is a far more complex question then just orbital placement we hardly expect most of these planets to be inhabitable or inhabited so it’s no surprise at all that in our own solar… Read more »
ari1413
Member
ari1413
February 3, 2012 12:46 AM

“GJ 667C had previously been observed to have another super-Earth (GJ 667Cb) with a period of 7.2 days, although this finding was never published.”

Amazing how far we’ve come. 15 years ago, that would’ve been among the most interesting stories of the year, now it’s so commonplace it’s scarcely worth publishing

Anonymous
Guest
Anonymous
February 3, 2012 9:40 AM

Does anyone know any work on possibility that planet avoids being tidal locked to it’s star because of influences of other stars in a multistar system? I believe this may not be the case at present star system, having wobbling ~1M at 50-200 AU distance is not enough to avoid bleeding angular momentum, but I’m wondering about general case.

vagueofgodalming
Member
February 3, 2012 10:17 PM

“GJ 667C had previously been observed to have another super-Earth (GJ 667Cb) with a period of 7.2 days, although this finding was never published.”

Actually, it was: http://arxiv.org/abs/1111.5019

Anonymous
Guest
Anonymous
February 4, 2012 4:41 AM

It’s only 4.5 times the mass of Earth (-: . Has no metal. Has three suns. Hey I’m ready to go now. Why do we continue to hear excitement about “earth like” planets that are nothing like the earth? What is exciting about that?

Glenn

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
February 4, 2012 1:13 PM

I’ll point you to my first reply to EricEdwin below. It is exciting for knowing more on planetary formation but mostly IMO more on abiogenesis!

Anonymous
Guest
Anonymous
February 7, 2012 2:51 AM

Planetary formation is extremely fascinating. So why not say it’s about planetary formation instead of hipping it as our new home? Couldn’t they say almost earth like planet? Isn’t honesty important in science? Hipe is not good for science. Thanks for your reply.

JFeral

________________________________
From: Disqus
To: [email protected]
Sent: Saturday, February 4, 2012 8:13 AM
Subject: [universetoday] Re: Potential ‘Goldilocks’ Planet Found

Disqus generic email template

Torbjörn Larsson wrote, in response to jferal:
I’ll point you to my first reply to EricEdwin below. It is exciting for knowing more on planetary formation but mostly IMO more on abiogenesis! Link to comment

Anonymous
Guest
Anonymous
February 4, 2012 10:40 AM

4.5 time the mass of earth. No metal. 3 Suns. Hey I’m ready to go now. Why do scientist continue to get excited about planets like this and call them “Earth like” Is there a part of the earth I have yet to hear about?

wpDiscuz