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Trio of Super-Earths Discovered
FiReaNGeL writes "A group of astronomers have now discovered a system of three super-Earths around a rather normal star, which is slightly less massive than our Sun, and is located 42 light-years away towards the southern Doradus and Pictor constellations. 'We have made very precise measurements of the velocity of the star HD 40307 over the last five years, which clearly reveal the presence of three planets.' The planets, having 4.2, 6.7, and 9.4 times the mass of the Earth, orbit the star with periods of 4.3, 9.6, and 20.4 days, respectively. 'The perturbations induced by the planets are really tiny — the mass of the smallest planets is one hundred thousand times smaller than that of the star — and only the high sensitivity of HARPS made it possible to detect them' says co-author François Bouchy, from the Institut d'Astrophysique de Paris, France. Clearly these planets are only the tip of the iceberg."
So which one are we going to fight over for oil?
Those who believe the Internet is private,
find their privates are on the Internet.
Why is it that most of the planets discovered have extremely short orbital periods compared to our own? Is it because those are the easiest types to detect, or is it because we are a cosmic oddity with our slow orbit around our star?
Also, I wonder if one were on one of these planetary speedsters, would you be able to tell you were whizzing around your star so fast.
a super-earth? It is a bigger planet with Earth-like atmosphere, or it this just a bad translation?
Every time there's news of earth or super-earth sized planets, we always find that they're orbital period is like 5 days, which would mean the planet is completely scorched and incapable of supporting life or bearing liquid water. Such a downer....it doesn't matter what sized planet you have if its orbit places it so close to the star. Is this because the whole eclipse-detection method requires the planet to be close to its star so we can't actually detect planets further out from the star? I'm actually kind of tired hearing about "exciting" new of another planet being discover 5-30 million km from its star...that is not even close to being in the habitable zone people.
What exactly makes these Earth-like? From the data it appears that their masses are several times greater than Earth and their orbital periods are much much shorter than Earth. Is it because the star they orbit is similar to Sol? Is there any indication of water or an atmosphere on any of them? Not that this isn't a cool find, but it seems that the use of the word "Earth" is just sensationalism. I would've been just as happy if they had simply said "three planets."
God, schmod. I want my monkey man!
> ... and is located 42 light-years away ...
So that was why the answer to the ultimate question was 42 - and the ultimate question itself must be something like "Are we alone in the universe, and if not, how many light-years away is the nearest other life?"
---they can't be very Earth-like. "Super-Mercury" would be more like it.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Space race just found a new meaning for its life, its universe, and everything.
With masses 4-9 times greater than Earth, I can't see these planets being very useful. Too close to their star to be habitable, too heavy to send mined materials into orbit.
The planets, having 4.2, 6.7, and 9.4 times the mass of the Earth, orbit the star with periods of 4.3, 9.6, and 20.4 days, respectively.
Anything orbiting a star in 4.3 DAYS is extremely close to the star, and could not possibly anything more than a cinder, probably at near rock melting temperatures.
Mercury has an orbital period of 88 days for comparison.
Sig Battery depleted. Reverting to safe mode.
Look!
Up in the sky!
It's an asteroid!
It's a planetoid!
It's SUPEREARTH!
Yes, it's Superearth, strange planet from a far away solar system with gravity and atmospheres far beyond those of mortal planets.
Gee, if we had a telescope array with a baseline of, say, the radius of the Moon's orbit, then we could resolve some REALLY small orbital perturbations, vastly improving our ability to identify planetary systems.
It occurs to me that such a system wouldn't even need to be (continuously) staffed after installation, just the occasional maintenance call.
I think I see an opportunity for a Lunar observatory project...
"My strength is as the strength of ten men, for I am wired to the eyeballs on espresso."
And how many Super Earths have you found, Mr. DadburnedNewfangledScience?
... swap Pluto for one?
Have gnu, will travel.
"So lacking any evidence that planets are ubiquitous, and even worse that true Earth-like planets exist in the first place even though they can't yet detect them, they are ready to say that they must exist because they have now found some "smaller" hunks of mass orbiting a star?"
No. They say that it's a pretty reasonable conclusion that planets are ubiquitous, based on how ubiquitous they are in the small areas we've studied and given no reason to suppose the small regions we've studied should hold more planets then usual.
"I thought scientific FACT was built on the presence of observed (not potentially observable... OBSERVED) evidence to support the hypotheses and tests devised when using the scientific method. I hope more of this new science, just like the new math, makes into all of those schoolbooks are youngsters are using in school these days."
Oh, you were around before "drawing generalized conclusions from samples when complete data isn't available" was thought up?
Has anybody seen Trillian?
Clearly these planets are only the tip of the iceberg."
Like tips of icebergs? Then they're NOT like earth but more like Neptune?? Wait didn't the summary say they were really really hot?
Huh?
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
when we get there, there aren't any nuked out cities
"Tip of the iceberg"? We found icebergs on a trio of extraterrestrial Super-Earths? That means water! That means life! That means green super-women, out there for the asking, who haven't heard how weird it is to have a space nerd boyfriend!
--
make install -not war
but maybe when we get there we could turn them into 20.3 Earth-sized planets in a decent orbit. We could also take the extra 0.3 and make a moon for each planet, or maybe something fancy like a ring. Who knows, by the time we actually figure out how to get there, we might be able to do this too...
Why are scientists/people surprised when they find new exo-planets? Let's see, there are at least 200 billion stars in our own galaxy (possibly up to 400 billion), and it is 100,000 light years in diameter. The Milky Way has 5 spiral arms, our solar system is located in the shortest arm, and our capability to locate exo-planets barely extends outside our own spiral arm. The record find right now is 17,000 light years away. So we can only see planets in a very small percentage of our own galaxy, let alone the estimated "hundreds of billions" of other galaxies! The one star we know the best (our sun) has 8-9 planets circling it. I'd be more surprised if they didn't find planets around almost every star they look at! There are more stars in the universe than there are grains of sand on the entire earth...
I declare these planets property of mine . Anybody trespassing on these planets will be orbitally bombarded.
As long as there are slaughterhouses, there will be battlefields.
What you mean like Pax and SElinux that have been around forever?
IranAir Flight 655 never forget!
superman?
The only possible interpretation of any research whatever in the 'social sciences' is: some do, some don't
Three super earths... probably one good earth, one bad earth, and one bizarro earth.
This am a terrible discovery. Me so happy me could cry!
It's how you use it! Ha ha what a lie.
IranAir Flight 655 never forget!
What is the maximum mass for Earthlike life? Certainly life as we know it could survive higher gravity; although, it might be confined to oceans. At what point would gravity be so high that we could rule out familiar life forms?
I know Sagan speculated on exotic life that might be able to float around in the upper atmosphere of gas giants like Jupiter, but that wouldn't be very Earthlike life as we know it.
They must be inhabited by super humans too - their gravity would crush our puny bodies.
I, for one, welcome our new Super-Earth Overlords!
I haven't a clue about what level of radiation is still acceptable, except that I guess it's much higher than accepted.. Factors:
- Radiation can vary a lot along location, especially UV, and (primary)alpha and beta radiation is easily shielded. As for gamma, how much gamma radiation is there ten feet under water?
- Planets with tight orbits always have the same side to the sun due to tidal forces. This gives a wide range of temperature and radiation level to choose from.
- Radiation breaks down dna/rna and any kind of cell material. It possible to have cells with huge redundancy and self-repairing capacity to withstand high levels of radiation? 1000 times more than what we have? a million? We're tuned to low radiation levels.
I wonder if red dwarfs are much of a challenge then. In fact, I can take on two of them for breakfast.
"perturbations"
Did they make this word from Pubes and Masturbation or is it just me?
...so we have Caprica, Sagittaron, and Picon. Three down, nine to go!
Random Thoughts From A Diseased Mind (Not For Dummies)
yeah i get the lunix thing now. wooooooooooooooooooooosh
IranAir Flight 655 never forget!
Are these Super-Earths populated by superhumans?
No, and these aren't three super earths.
"Kill 'em all and let Root sort 'em out"
The actual force of gravity at the surface of a planet is not just a function of the mass of the planet. It is also a function of the radius of the planet. So, if a planet had more mass than earth, but also had a radius that was the right size, it could have the exact same surface gravity.
/R^2)
I believe the function is something like:
G * ( [M1 * M2]
Where G is the universal constant of Gravity, M1 is the mass of a test object, M2 is the mass of the planet, and R^2 is the average radius of the planet, squared. Since we have a fraction, if M2 increases, you can keep the fraction constant by also increasing R.
So, to give a bit more concrete example, if the planet has 2 times the mass of Earth, and the radius is Square-root of 2 times the mass of the earth, then the Force of Gravity at the surface is the same.
"Square-root of 2 times the mass of the earth" should read "Square-root of 2 times the radius of the earth".
Also, more generally, if the mass of a planet is X times the mass of the earth, then if the radius is also Sqrt of X times the radius of the earth, the Force of Gravity will be the same.
"Clearly, these planets do not satisfy the Earth-like gravity requirement of a class M planet."
I've posted more details in another thread, but in summary, the Gravitational Force experienced at the surface of a planet is not just a function of the mass of the planet, but also of the size of the planet (specifically, the length of the radius of the planet). A planet with more mass than Earth can have the same gravity as earth, so long as the size is also larger (so it would have to be less dense than the earth, which still means it's probably not very earthlike).
Sorry for not being funny, but I couldn't find an intelligent comment to attach this to, so it goes at at top level.
basically, my opinion is that it is within our reach to create a number of large telescopes that will exist roughly within the solar system, though possibly above and below the solar plane. These telescopes will be primarily automated, though a human team may need to be maintained ex-earth to do repairs and upgrades. All of these telescopes will be controlled by, and report to, all of the next generation super computers this race seems to be so good at creating (as opposed to high speed transportation systems). the ultimate goal is to be able to see the planets directly, and to observe and estimate the possibility for life as we know it (roughly). Where life does not exist, we seed it, though it may take generations to arrive, and thrive. This is our goal as a race, is to spread terran life as far as it can be spread. this is why the plants put up with us. It is our manifest destiny.
I'd think the super-Jupiter kind of planet would be a good candidate for hosting life.
I mean, not the planet itself, but if they are similar to Jupiter, they could have one or more Earth-like satellites in stable circular orbits.
First, it's not a red dwarf (spectral class M); it's toward the hot end of spectral class K, which means its peak output is at a lower frequency than the sun but higher frequency than any M class star. Suppose it's K2 or K3 (I don't know that, but a main sequence star of about .74 solar masses is about here, at, say, 4500K). Then the wavelength at which the highest output occurs is:
.742*Msol = 1.48*10^30kg
.72*Rsol = .500*10^6km, so it's about 6.5 million km from the photosphere given the stellar massand orbital period.
.5~.6 AU or so: .55 AU
.05 AU. .05 = sqrt(luminosity) => luminosity is only 1/16th the luminosity of the smallest, least luminous red dwarf stars possible. That is to say that a distance of only 7 million kilometers is a searing hot orbit around anything that's hot enough to be a star.
wavelength = (2.90*10^-3)/4500 = 644nm
which is in the red, but visible part of the spectrum. There would of course be far less output in the ultraviolet for such a star.
Let's look at the orbital distance:
T is 4.3 days = 4.3*24*3600 = 371520s
M for HR40307 is
T = 2*pi*sqrt((a^3)/(G*M))
T/(2*pi) = sqrt(a^3)/(G*M))
(T/(2*pi))^2 = a^3 / (G*M)
G*M*(T/(2*pi))^2 = a^3
a = [G*M*(T/(2*pi))^2]^1/3
plug & go:
= [(6.67*10^-11)*(1.48*10^30)*(371520/(2*pi))^2]^1/3
= 7,014,511,037m
~=7.01*10^9m
or 7.01*10^6km
Compare to ~150*10^6km for Earth, or 58*10^6km or Mercury.
The radius of HR40307 is
The uncertainty hinges mostly on the value of M, which is on [.690,.787] solar masses. HR40307 is something like a K2 or K3, so it's got a smaller "habitable zone" closer to the star than a G2 like our sun, around
~.3 solar luminosity, so
sqrt(.3) =
But, this is still WAY inside that at less than
Feel free to run the numbers above in the most conservative way possible: lowest mass (thus lowest luminosity and closest habitable zone inner-bound) for the star still won't get even the furthest planet to the point where water condenses at any physically plausible atmospheric pressure. Even the coolest situation is still too hot for an atmosphere on such low-mass planets anyway; nothing that close is cool whether it's massive enough to retain an atmosphere that close or not.
The atmospheric composition and albedo can modify the surface temperature somewhat, but it can't reduce the temperature below thermal equilibrium without being a perfect reflector, which is why the habitability zone approximation is a good one.
The Nazi's are already living on these planets! We are a doomed mutation! Remember that!
Its totally the Firefly star system. Gentlemen, lets get terraforming!
With the LHC they are spending 5 - 10 billion dollars. They are doing this because they know if they built it They will learn something funamental about the universe, even if its that the current theories are wrong. It seems to me that we are at the point now that spending this type of money on planet detection would be garanteed to either 1) find planets that could support life as we know it. 2) Find an earth like planet with life on it. 3) give an much more accurate view of the possible number of planets with intellegent life. Finding another life filled planet would affect everyones perception of our world and our place in the universe.
I guess that makes them "mostly" Earth-like...
Oh dear.... that sounds like the US agenda, not to mention the book of the same name. Still, i am in agreement. We dont know how long this little blue ball we live on will be around... cosmic accidents do happen. Better if we spread as far as possible regardless of the cost.
Just wait until they find Kobol, things will get interesting then.
"The ability to chop up 3 planets and turn them into 20 while changing their orbits and creating some cool moons around them is insignificant next to the power of the force."