Super Earth!

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‘Super-Earth’ spotted in distant sky

European astronomers announced they had found a “super-Earth” orbiting a star some 50 light years away, a finding that could significantly boost the hunt for worlds beyond our Solar System.

The planet was spotted orbiting a Sun-like star, mu Arae, which is located in a southern constellation called the Altar and which is bright enough to be seen with the naked eye, they said. […]

With few exceptions, the extrasolar planets spotted so far have approximated the size of Jupiter, the giant of the Solar System.

But this latest find is far smaller, with a mass of only 14 times that of the Earth, which puts it in the same ballpark as Uranus for size.

The big difference, though, is that Uranus is an uninhabitable hell, a gassy planet on the far frigid fringes of the Solar System, whereas the new planet appears to be a rocky planet, as the Earth, Mars, Venus and Mercury are, and orbits in a much balmier region.

It has a gassy atmosphere, amounting to about a tenth of its mass, although what this consists of is so far unknown.

The object qualifies “as a ‘super-Earth,” the ESO said.

Much about this enigmatic world remains to be uncovered, least of all whether it may be habitable.

However, there is the tantalising question as to whether it lies within the “Goldilocks Zone” – a distance from its star that is not too hot, not too cold, just right.

In this zone, a planet would be close enough to the star to have liquid water – yet not so close that its oceans would boil away – and not so far that its oceans would freeze. That is one of the prime conditions for creating and sustaining life, according to a leading theoretical model. […]

I suppose if this turns out to be a habitable planet, that would put a serious kink in the “Privileged Planet” arguments. Though in my opinion those arguments suffer from serious logical flaws and don’t really require emprical disconfirmation, but it’s always cool to know that Super Earth is out there. Maybe this will finally cause the real estate bubble to burst.

62 Comments

Saw it as well, seems that the close proximity to the sun may cause the planet to be a ‘bit’ warmer than our earth. Still it’s good that astronomy is now finding smaller planets which are more earthlike rather than the gas giants. Finding earth like planets of size and location similar to our earth may IIRC still be beyond our capabilities. Or at least it will require observations of a longer duration.

So does the increased gravity (14g) mean that any life there would probably be similar to deep sea organisms, which have to live at increased pressures?

Most likely they’d be extremely strong and resistant to damage. If brought to a lower-gravity world like ours, they could leap great distances and perhaps even fly.

I mean, that’s how it works for Superman.

(Comic books aside, I’d imagine the main result would be reduced size because of the difficulty of self-support. Gravity and pressure aren’t really similar in their effects AFAIK, since one is directional and one is not.)

PVM Wrote:

Or at least it will require observations of a longer duration

There are a few interesting ways we are detecting these planets and it just keeps getting better. Transit and stellar wobble are just 2 of the current methods of locating the planets.

With this planet having a rocky solid surface and 14 times the mass of earth that would put it about 2x our gravity correct? (I’m assuming the density is some where between the moon’s and earths (4.4 half way between the moon’s and Earth’s)

A “year” of 9.5 days suggests that the planet is on the verge of incineration in the photosphere.

gwangi Wrote:

So does the increased gravity (14g) mean that any life there would probably be similar to deep sea organisms, which have to live at increased pressures?

14x the mass does not = 14x the gravity. Uranus 14x the mass of earth yet only has .91 the gravity of earth because its density is lower.

From my estimation 14x the mass at a density of half way between the moon’s and earth’s (3.3 for the moon and 5.5 for the earth), ie using a desity of about 4.4, would put the diameter about 33,000km as compaired to our Earth’s diameter of about 12,700km. This would put the gravity just over twice that of Earth’s. Given this info if the density of the planet is even that of earth its gravity would only be 2.4 that of earth.

Still within bounds of terrestrial life. If I was a bit better I should be able to work backwards and work out the distance it orbits from its sun given the orbit is only 9.5 days.

Any math/physics genious out there that can do the math in there head?

Wayne Francis Wrote:

14x the mass does not = 14x the gravity. Uranus 14x the mass of earth yet only has .91 the gravity of earth because its density is lower.

Actually, 14x the mass does equal 14x the gravity: F=GMm/r^2. Uranus has less gravity than earth on its surface because most of the mass of Uranus is in its thick atmosphere.

Wasn’t there something about the side toward the sun being at a temp of around 1400 degrees?

Reed wrote

Actually, 14x the mass does equal 14x the gravity: F=GMm/r^2

The surface gravity is 14x stronger only if the radius is the same.

A better way to look at it is that the surface gravity (acceleration) is proportional to the density x radius.

Wayne wrote

Still within bounds of terrestrial life. If I was a bit better I should be able to work backwards and work out the distance it orbits from its sun given the orbit is only 9.5 days.

The cube of the distance (semi major axis) from its sun is propotional to its sun’s mass x the square of the period (9.5 days). Thus, it is impossible from this data to work out the distance without the mass of the sun. Around our sun, a circular orbit of period 9.5 days would put you at (9.5 / 365) to the 2/3 power or about .088 times closer than earth, or about 8 million miles.

I do have a question (a serious one, not just trying to pick a fight) for evolution proponents. I know what finding fossilized microbes on Mars would mean for ID (nothing), but I am wondering what the short answer would be for evolution. Please no name calling, I am genuinely curious. In fact, I’m writing a novel where a character has to answer just that question, so I am interested in an answer at a popular science level.

Okay, now I see why Wayne was discussing density.

David: I know what finding fossilized microbes on Mars would mean for ID (nothing), but I am wondering what the short answer would be for evolution.

Some ID proponents fear that finding life outside earth would mean something for their faith beliefs. ID, scientifically has little to offer in predictions or hypotheses so I agree with you that finding fossilized microbes on Mars would mean nothing to ID. For science it would mean that life may originate more often than expected.

You have stated elsewhere that you believe astronomy holds the strongest evidence for ID. Since we have yet to hear about ID relevant thesis, I was wondering what ID has to offer here?

Pim,

I kept my question narrow: fossilized (or even better, living) microbes on Mars. This would have no impact on ID because it could be claimed that they came from earth via debris blasted into space from collisions. (not here to defend that, just pointing it out). It is all but certain that there is, on Mars, material that originated on earth. It is also speculated that microbes could survive the journey. The evolution question would be, why didn’t they “find a way” to survive or advance on Mars? I don’t know how evolutionists would answer that contrived possibility.

I am not sure about the ID question–in cosmology ID is based on probability. Incredible constraints on things such as the expansion rate of the universe (we easily could have had no stars or a big clump), reaction rates and nuclear levels (for necessary stellar evolution), etc are impressive enough that even agnostics/athiests recognize that it cannot be ignored–hence parallel universes vs. ID.

Is that what you are asking?

That planet has to be fried and not long for this universe. mu Arae is quite similar to our own sun.

The evolution question would be, why didn’t they “find a way” to survive or advance on Mars? I don’t know how evolutionists would answer that contrived possibility.

Pure speculation, of course (for all I know some living thing of terrestrial origin did survive or advance on Mars):

The likelihood of a cell surviving the heat and force of whatever event knocked it off Earth, times the likelihood of surviving the radiation hazards of the trip to Mars, times the likelihood that it found anything on Mars to eat, times the likelihood of several other contingencies necessary for replication (let alone survival)… strikes me as “SubDembskian”.

Evolution tells us that living things adapt to the environment(s) they actually encounter, while (at least some strains of) ID tells us that they are “designed” to survive the rigors that “the Designer(s)” foresee in their futures. My take is that the environment during the journey and upon arrival on Mars would be so different from anything the cell had co-evolved with that its chances would be vanishingly small.

Rusell,

Thanks for the answer–which makes sense if only remnants of microbes are found. If live microbes were found, is that a problem (why they never advanced) or at least a puzzle for evolution?

David Heddle Wrote:

live microbes were found, is that a problem (why they never advanced) or at least a puzzle for evolution?

Why would it be? Microbes existed on Earth for billions of years before “advancing” to a multicellular state.

Exactly why it happened this way I’m not sure, but there are two obvious possiblities: The first is that unicellular life had to slowly build up complexity, and that multicellular life could only come about once a certain threshold had been reached. The second is that extremely rare chance events were required for multicelluar life, and those events didn’t first occur until about 800 MA. On a different planet, they may have occurred quickly, or not at all. Both possibities are compatible with each other.

David Heddle, still pretending, asks:

If live microbes were found, is that a problem (why they never advanced) or at least a puzzle for evolution?

Yo, David, since when evolution is about “advancing”? Staying the same can be a beautiful thing, especially when one’s fitness is strong and one’s environment is static.

Of course, phenotypically an organism can look the same to us, but lots can be going on at the genomic level.

Today’s microbes may look like yesterday’s microbes (at first glance) but if we could go back in time and study the first microbes they would probably be very different at the molecular level from most of the microbes we know today. Saber-toothed tigers aren’t just tigers with big teeth, you know (in spite of the name, which is just a name).

Science is fun, David! And biology is even more fun. Maybe someday you’ll actually know something about the subject.

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Heddle writes

“As I said before, I am glad you are not on my side”

I’m glad I’m not on your side either. The game is over, your side lost by 20 runs, the lights are turned off, but you’re standing out in left field.

“I had asked a real question, I wasn’t baiting. Steve R gave a sensible answer, but you choose just to, well, be you.”

You’ve been asked “real” questions by others, David, but you haven’t answered them coherently or, in some cases, you haven’t even tried to answer them.

FYI: I am not interested in your publication record, David. What is abundantly clear is that you know very very little about biology and yet you seem to have a strong opinion (or at least, you had one earlier) about how pseudoscientists who attempt to publish in the field of biology are treated unfairly.

My point is that your opinion on the subject is worthless and you have said nothing to persuade me (or anyone else) to the contrary.

I will add, to soften the blow to your fragile ego, that you are certainly not alone in expressing your views on the subject of “intelligent design” in the absence of a rudimentary understanding of the basic principles underlying evolutionary biology. On the other hand, you are not in good company.

By the way, where’s the physics blog where I can complain about how physicists don’t fairly treat papers arguing for an earth-centered solar system?

David Heddle Wrote:

I do have a question (a serious one, not just trying to pick a fight) for evolution proponents. I know what finding fossilized microbes on Mars would mean for ID (nothing), but I am wondering what the short answer would be for evolution.

It probably would have no direct effect on what we know of the evolution of life on earth. Depending on the genetic makeup of Mars life, it could conceivably provide some support to panspermia, or help us come closer to a theory of abiogenesis. Evolution takes life as a given, thus does not require a theory of abiogenesis, and in fact is consistent with the possibility that abiogenesis may be extremely rare (or “impossible” in anti-evolution-speak). Alternatives that deny common descent, however, do require a theory of abiogenesis, because that is how they imply that new species (or “kinds” in anti-evolution-speak) originate. Note that even some IDers accept common descent, because they know that the alternative is exceedingly less likely, with or without a designer. Of course that doesn’t stop them from implying otherwise in their “big tent” strategy.

Frank J,

Given that the universe has finite age, how can it be that evolution does not require a theory of abiogenesis?

Because it takes life as a given. Duh. Did you read what Frank wrote? In other words, how life may have arisen is irrelevant to how it subsequently evolved.

Pim,

Yes I read what he wrote, I was looking for more than a “duh”. At times you hope that people assume that you read what they wrote and infer the obvious question. I see that was a bad assumption.

So, more explicitly,

If it is not a question for evolution, then what sub field of biology does it fall under? Does all biology just take life as a given?

Your new question is very different from your earlier question. Fine, lets move on. As you already stated the origin of life falls under abiogenesis.

Quite exciting area of research looking back over 3.5 billion years to figure out what happened. Likely candidates include DNA world preceded by RNA world preceded by lipid world. Interesting issues include homochirality, origin (and evolution) of genetic code.

I found the OOL at Weizmann a fascinating resource. Other research can be found at these links

Thanks. I guess my question was dumb: I was asking what subfield dealt with the abiogenesis problem. I gather the subfield is called abiogenesis. My bad. Thanks for the links.

Of course, the really juicy ID question (in my mind) is not ID vs. evolution, but how we have a world hospitable for life. That’s the ID vs. parallel universes and Sagan (not a misspelling) question. But that is not the stuff of this blog.

I will be posting a new updated review of the Privileged Planet idea by Gonzalez and Richards soon where I will show that the question is ill-posed. Life would not have evolved if the earth had not been habitable. In other words, the question may be tautological. In fact it presumes that earth like environments and earth like life are the only relevant forms. Correlation v Causation…

Of course, the really juicy ID question (in my mind) is not ID vs. evolution, but how we have a world hospitable for life.

The muffin I had this morning came out of the oven with a little indentation in the top crust, the perfect size for a small slice of salted butter. Praise the Lord! Will His miracles never cease?

Why Christian inevitable will see the hand of the Lord (David Heddle) in nature. But that hardly makes it scientific evidence. It’s poor argument scientifically but a powerful one apologetically

Likely candidates include DNA world preceded by RNA world preceded by lipid world.

Those are interesting worlds. This summer I was immobilizing proteins by putting them in tiny lipid bilayers. given that all it takes for a lipid bilayer to self-assemble is to squeeze some lipid molecules through a very small hole (mine were 50 nm) with water around, it’s no surprise life took this direction.

Now add clay/minerals and homochirality may be resolved as well

This same clay (montmorillonite) that will catalyze the formation of RNA will also lead to a spontaneous process in which small vesicles are formed with the fatty acid making a wall and trapping water and the RNA molecules inside.

Powerful stuff

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David Heddle Wrote:

FLRW is an isotropic universe, but not a spatially infinite universe.

The FLRW metric can describe universes with constant positive, zero, and negative spatial curvature. Such universes with positive curvature are necessarily finite. Ignoring the possibility of certain mathematical tricks*, such universes with zero or negative curvature are spatially infinite.

David Heddle Wrote:

The standard analogy (not for erik, he must be a physicist so I am sure he has heard this) is to think of a 2D universe consisting of the surface of a balloon. Blow the balloon up just a little (just post big-bang, as it were). With a marker, place dots on the balloon. Assume the universe is 2D, i.e. you are constrained to the surface of the balloon. As you blow it up, the dots all get farther apart—every galaxy is moving away from every other galaxy. Also, the universe is getting bigger—it is not filling empty space. Also, not space on the balloon is preferred—there is no center of the universe.

However, it must be remembered that the surface of a spherical balloon has a constant positive curvature. It is therefore bound to be (in certain respects) a misleading way of visualizing FLRW universe with zero or negative spatial curvature. The balloon analogy is good for driving home the point that there is no center of the universe and that the distance between galaxies grows. But like all analogies it is misleading in some respects, e.g. one might be lead to think that the universe is necessarily spatially finite.

David Heddle Wrote:

To point out that we are at a period of optimal observation, I’ll direct you to another sci am article here and especially the sidebar picture here

Notice the statement: “in spacetime diagrams (right), galaxies follow sinuous paths that take them in and out of the observable region of space”

That’s a pretty minimalistic, and not very helpful, reply to my inquiries. I must confess that I do not understand the picture (why is the limit of the observable universe a straight line in the space-time diagram? null geodesics are typically not straight lines in curved spacetimes). Perhaps you will elaborate on what significance you see in the Sci. Am. article and the sidebar, in particular.

David Heddle Wrote:

In a simple minded picture where we only have to wait long enough for light from distant galaxies to reach us, then galxies would only move into the observable region, never out of it.

In fact, that is the case in my above example with a flat FLRW cosmology with scale factor R(t) ~ t1-a. I wouldn’t rule out that galaxies can move in and out of the observable region in more complicated cases. I have yet to see it, though.

Maybe it’s an issue about the precise meaning of “observable region”. Are you referring to the region within the object horizon (aka “particle horizon”), the event horizon, or something else?

—————— R. M. Wald, “General Relativity”, p. 95, writes that spatially finite universes with zero and negative spatial curvature, but that “it does not appear natural to do so”.

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This page contains a single entry by Steve Reuland published on August 25, 2004 6:37 PM.

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