Slashdot Mirror
Rocky Planet Discovered
Fraser Cain writes "Astronomers have discovered a rocky, terrestrial planet orbiting a nearby star, Gliese 876. The planet has approximately 7.5 times the mass of the Earth, double its radius, and orbits its parent star once every two days. This is the most Earthlike extrasolar planet discovered so far." Reader Karthik Narayanaswami points out that "the planet was discovered by the famed Berkeley astronomer Geoff Marcy," and adds a link to the news release from Berkeley.
Oh wait... you said Rocky Planet.
sheesh...
I thought they meant a bizarro world where everyone is Rocky Balboa.
Here is the link to the Berkeley press release and information on Berkeley astronomer Geoff Marcy.
And oh, looks like Slashdot is continuing to mirror Boing Boing.
The planet has approximately 7.5 times the mass of the Earth, double its radius, and orbits its parent star once every two days. This is the most Earthlike extrasolar planet discovered so far. We've got a ways go to if this is the most earthlike one. This was detected via the "wobble" method; how advanced are other methods of extrasolar planet detection methods?
The team measures a minimum mass for the planet of 5.9 Earth masses
It seems that planet's gravity is quite big for "earthlike" planet. Is life possible at all under such gravity? Any examples?
With a new year every two days, everyone would be broke buying birthday cakes.
The age and technology have come for the ability to discover planets other than our own and the possibility of life on these planets. All that is needed are thousands of hours put in by astronomers - more than is currently the case. Space is just too vast!
The thing has gotta be mighty close to the star. Mercury orbits in 60 days, right? This thing may not be a gas giant, but it must totally bake on the sunny side, and aren't there going to be some horrendous tidal forces with an orbit that close? It probably has no shortage of volcanism. Hey! It's Vulcan, maybe... if it can hold an atmosphere without having the stellar wind blow it all away. Whatever, it can't be Earth-like.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
All four seasons in one day (or two days actually)
If it is, does that mean Spock mates once every 14 days?
which is only 15 light years away
So why not send some radio traffic which would obviously not be of natural origins. Surely 30ish years isn't that long to wait for a reply? (assuming the place has lifeforms which developed radio...)
Trolling is a art,
If we moved there would we live to be 10,000 years old, or die in 160 days? Before you get your brain all twisted, I meant this as a joke.
God spoke to me.
...you would wonder if all the women were named Adrian.
FLR
dorsai :)
The gravitational force is proportional to the mass but inversely proportional to the square of the distance from the center of mass.
If the planet is actually twice the diameter and, say, six to eight times the mass, the surface gravity might be 1.5-2G. I'm not sure how survivable this would be, but it doesn't seem unreasonable.
Yo Adrain, We did it eh?
The days of the digital watch are numbered.
Being funny is my sig nature.
all the women look like Talia Shire.
Adriaaaaaan!!!!
When information is power, privacy is freedom.
adriannnnnnnnnnnnnnnnnnnn!!!!!!!!!!!
(Lameness filter encountered. Post aborted!
Reason: Don't use so many caps. It's like YELLING.)
(it's supposed to be yelling!!!!)
Maybe someday they'll find evidence of a planet that actually might resemble earth in some way. Other than the fact that it's made of rock and orbits a star, theres not really much we can do with it.
If we'd spend less gazing at stars (at least in the optical range) and more to actually develope an inexpensive space route the public might show more intrest in space. LONG CHAIN THE NANO-TUBES
Bacardi + slashdot = negative karma.
/monster emerges from hat.
N: What we do with Moose and Squirrel?
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Sounds nice but I wouldn't want to live there.
The days of the digital watch are numbered.
Gravity is only 1.8 from normal - I believe you can get used to it. Meanwhile surface is 3.2 times larger, so if it could be terraformed it will hold a lot of people from our overcrowded Earth.
Of course I put many questions aside like how would they get there, does it have any continents, how sensitive processes like childbirth are to the gravity, does its atmosphere shield properly from radiation, isn't it too cold/hot there (although this can be fixed) etc etc...
Its always interesting when we find these new planets in other systems, but the wobble method is just not effective for finding an earthlike planet. For starters, have you ever noticed all the planets found have extremely quick orbits (1 year = 2 days) etc. And infact the longer their year is the bigger the planet is (because although the wobble doesn't occur as quickly it is more pronounced. If a planet were to have orbits similar to ours it would take nearly 2 years to see one wobble back and forth. Sure its neat to find new planets but I don't think we need to be spending all our time looking for wobbling stars. For every star that wobbles there are probably more just sitting still with planets around them more similar to ours that we just cannot detect.
Also, I tend to think if you see a start wobbling back and forth its because there is one large mass in its orbit affecting it, as opposed to many planets balancing things out at various points around the start. Does our Sun wobbel like this? I am not sure, but if not, it hardly seems a good measure to find an earthlike planet, but rather a good way to find large sole planet systems.
I am not an astronomer, but isn't mars more earthlike than that?
Well, it is actually somewhat true, including the whole aging factor: 1. What seems like two days is really a year and makes you feel really old. 2. Now that you have gained all of those years really quickly, you start to feel a little bit heavier...
I think for my birthday present I'd want Dramamine. Zipping around that fast I'd get motion sick.
It is easier to believe the wobble is due to some temporary imbalance within the star, than to believe that a planet that size formed that close in. The chances the star "captured" it that close are also unbelievable.
Maybe something big actually hit the red dwarf and is slowly finding its way to the center of gravity.
Hence, only the lean and fit would survive.
(Then again, because this planet is so close to a star, its surface temperature is 400 to 750 degrees Fahrenheit and the electricity bill for A/C would certainly kill you even if the gravity doesn't).
Dedicated Linux servers (root access) $45 p.M.
well there's already a constellation Apollo.
Don King to promote
Adrian!!!
"It's a tarp!" -- Dyslexic Admiral Ackbar
Seems to me that this is the core of one of those too-close Jovian types, and not a started-out-that-size planet.
Astronomers are bad at talking. Your left nut is more "earthlike" than this space-brick.
This planet's "year" is two Earth days. But how large is its orbital radius (other than "so close to the star's surface")? So, how fast is its orbital velocity? Is it so fast that the centripetal "force" (illusion) of its orbit is significant, compared to its (greater than Earth) gravity?
In fact, even Earth seems like it should have centripetal effects. We rotate 1000MPH; we're orbiting at something like 70,000MPH, right? Shouldn't Earth gravity be balanced by detectable acceleration along the tangents to those circular motions?
--
make install -not war
After reading the article it seems like they "discovered" the planet simply by observing the star and two very large jupiter type gas giants that are circling the star. By the orbits of the planets and the "wobble" of the star they have determined that there must be another planet of the specified size and orbit.
So essentially this planet was discovered solely on observation of its gravitational effect on other planets. In other words the scientists built a computer model which includes the star and two visible gas giants, and found a planet which they could insert in it so it causes the star and the gas giants to behave as they in the model as they do in observation. Then they declared that they have discovered a new planet.
How did they know it was a rocky planet? Well, correct me if i am wrong but it seems like they decided that by elimination -- the planet is too small to be a gas giant and too close to the star to have anu liquid water on it. Therefore, it must be a rocky planet.
Admittedly I do not know much about modern astronomy but all of this is a little troubling. I mean should we not obtain direct observation from something before we proclaim it "discovered"?
I am sure modeling solar objects is very useful but modeling is limited to our current knowledge. If rely too much on modeling we will never discover anything that we do not already know about.
Please, someone...
do not try to pick up fight with the natives ...
If you double the radius, then you get 8 times the volume. Given that the mass is 7.5 times as much, this means that the density is slightly less than Earth's overall density.
The summary makes it seem like the planet is somehow extremely dense, which it is not.
The favourite possibility of sci-fi authors for life on planets like this is in the polar "twilight zones". It'd be a hard, hard life (the winds would be killer hot or cold) but life has been found on some pretty strange places on Earth...
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Rule #1: Do not talk about our secret Earth-like planet.
This guy must be from Rocky Planet: http://theteatime.free.fr/talc/rocky.html
No.
A body moving in a circle of radius R at a uniform speed V experiences an acceleration a = (V*V)/R towards the center of the circle. In neither of the cases you mention does any centripetal acceleration come close to the local gravitational acceleration at the surface of the planet.
Case 1: The Earth: orbital speed V = 30 km/s, and R = 150 million km, so (V*V)/R is of order (10^8)/(10^11) m/s^2, or about 10^(-3) m/s^2. The local gravitational acceleration is about 10 m/s^2, of course. If you speak of the Earth's rotational motion at the equator, then very roughly V = 500 m/s and R = 6,400,000 m, so (V*V)/R has magnitude roughly (2.5 x 10^5) / 6.4 x 10^6 = 0.03 m/s^2; again, much less than 10 m/s^2 due to the gravitational pull of the Earth.
Case 2: The new planet. Its orbital radius is about 2 billion meters, so the circumference is about 7 billion meters; if it travels that distance in a period of 2 days = 170,000 seconds, then it speed is about V = 40,000 m/s. The orbital centripetal acceleration is therefore of order (16 x 10^8)/(2 x 10^9) = 0.8 m/s^2. That's much larger than the Earth's orbital centripetal acceleration, but still far less than the likely gravitational acceleration at the surface (or cloudtops) of this planet.
Michael Richmond "This is the heart that broke my finger."
mwrsps@rit.edu http://stupendous.rit.edu
This hot "super-Earth," just 15 light years away, travels in a nearly circular orbit only 2 million miles from its parent star, Gliese 876, and has a radius about twice that of Earth.
I think it's only a guess - the radius can not be measured by the doppler method. It could be measured if the planet would pass in front of the star as seen from earth.
From TFA:
In reality, astronomers do not know if the planet is rocky or gaseous, like Jupiter.
This one.
But seriously, marine life lives under much greater pressure then life up on the surface. This is not quite the same because to float you'd have to displace much more fluid.
But in general, micro-organisms and small (low mass) life-forms like tiny insects are not influenced by gravity as much as us big lumps. They are much more sensitive to fluid viscosities of the liquid they live in, osmotic pressures, diffusion lengths etc. There is no reason to think a bit more gravity would prevent life from evolving.
Tell me when they find the Bullwinkle planet. Bullwinkle was always funnier.
Is there some physical reason why massive rocky planets cannot form, or are we assuming that massive planets in other solar systems must resemble massive planets in our solar system?
What's "earthlike" about it? The fact that it is orbiting a star? Seriously, all planets fit this description.
same result
...with slightly lower surface temperatures, as this one ranges from 200 to 400 degrees, obviously uninhabitable. If they could locate one that closely mirrors the earth as far as environmental and atmospheric conditions, then we could start focusing on how to start migrating humans via cryogenic and hyperspace travel to said planet. Would solve earth overpopulation problems.
Meh.
I was listening to Portishead "Wandering Star" softly in the background, and the lyrics I kept half-hearing were "Wobbling Star". Freaky.
*relative* to Earth, the equation simplifies to:
;-)
relative_mass / relative_radius^2
I.e., 5.9 / 2^2 to 7.5 / 2^2 == 1.48 - 1.88 g
Though, I have to admit that I know of no normally occuring life under those circumstances
Case 2: The new planet. Its orbital radius is about 2 billion meters, so the circumference is about 7 billion meters; if it travels that distance in a period of 2 days = 170,000 seconds, then it speed is about V = 40,000 m/s. The orbital centripetal acceleration is therefore of order (16 x 10^8)/(2 x 10^9) = 0.8 m/s^2. That's much larger than the Earth's orbital centripetal acceleration, but still far less than the likely gravitational acceleration at the surface (or cloudtops) of this planet.
But this is more than sufficient that if there were intelligent life (fabulously unlikely) then they would quickly notice that things were a few percent lighter at night than during the day.
The planet has about 7 times the mass of Earth and about twice the radius, so the surface gravity will be...pause for algebra...about 2g ~ 20 m/s**2. At night, the orbital centripetal acceleration acts against the surface gravity, so it would be a minimum at midnight of 19.2 m/s**2, and during the day they act together for a max at noon of 20.8 m/s**2, or a little less than a 10% difference.
This is conceptually closely related to tides, and this is another way of pointing out that the tidal effects on such a world are going to be wickedly large.
Blasphemy is a human right. Blasphemophobia kills.
I can hear it screaming now...
All the worlds indeed a
They don't know how fast it is spinning.
Wasn't another rocky extrasolar planet discovered last August, orbiting Gliese 436?
Why are we constantly finding these rocky planets orbiting M-Class red dwarf stars? Is there some correlation? (Possibly, these are the aged, burnt-out cores of old gas giants whose gassy layers have been blown off by their parent star?) Or is this the only type of star being surveyed for rocky planets?
Has anyone calculated what the surface gravity of this planet would be and what effect that might have on the existence of liquid water? I mean, on Earth water boils at 100 degress celius at sea level. If this planet does have an atomosphere perhaps the pressure on the surface is enough to allow water to remain liquid at much higher temperatures?
but I sure as hell wouldn't want to move there.
A story on the housing market in the Gliese 876 system reported a slight rise in new housing starts, but the real news is the frenzy of speculation. According to the Gliese 876 Housing Market Letter, permits for new homes on the rocky planet and its Jupiter-like siblings "totaled 5,294,101 in April, down nearly 2 percent over the past 12 months."
The sales are phenomenal. "New-home sales reached 4,886,393 in April, up 26.2 percent from 3,871,936 in April of last year; and year-to-date closings through April totaled 16,728,439, up from 14,511,600, an increase of nearly 15.3 percent. Among resale homes on the rocky Earth-like planet, which has experienced the most rapid appreciation of any location in the Gliese system over the past 18 months due to its non-gaseous, hard rocky surface and relatively excellent schools, 12,495,153 resale homes changed owners in April, up 27.7 percent from the 9,783,765 sold this time last year. Many properties are being bought and sold sight unseen by speculators on other planets. The year-to-date resale total through April is 42,473,257, up nearly 34.9 percent from 31,497,223 sold during the same time a year ago."
Gliese 876 may be a nice place to live, but there is no way 17,000,000 households moved there so far this year, given the high surface temperature (600 K) which tends to degrade mortgage paper and other financial loan instruments, and the high surface gravity (4.7g) which encourages speculators to look for "teardowns" when choosing properties to flip. Neither can the shortage of land excuse be used, since the planet has four times the surface area of Earth. Any oceans would have boiled away in the heat, leaving a dry surface behind and dumping huge amounts of pricey real estate onto a market that has become completely uncoupled from its fundamentals. It is obvious the speculators are running wild on this planet and in huge numbers. Hang on to your hat, Gliese 876!
Of course.
In a Futurama episode, Fry has to deliver pillows on a planet with heavy gravity and when he ends up breakin gthe lift, he has to haul these 200lbs pillows from the ship to the client.
Needless to say, Leela was pissed off at him.
Can someone do better?
It's a massive rocky extrasolar planet, with much higher gravity than Earth's, orbiting extremely close to its parent star, an M-class red dwarf -- A RED SUN.
Sound familiar? Perhaps, even, super?
... puts a whole new meaning to the phrase "all seasons in one day".
Well, if you climb into space to the world where you live, you better be ready to beat a hasty retreat to the stars...because if this new planet's star starts burning and exploding, then the dust from this distant earth-like planet might just shower over everyone.
I'd love to stay and chat, but I'd better be home soon.
From TFA:
Um, no, that's not true - there certainly are bacteria which can survive these temperatures and have adapted to them (those living near hydrothermal vents at the bottom of the ocean, for example). Whether this new planet could (even theoretically) host life is another question entirely, of course, but the statement that we do not know life that can endure such temperatures is simply not true.
quidquid latine dictum sit altum videtur.
Note, on the other hand, that .03 is a significant effect if you've memorized 9.803 m/s^2. For that matter, things effectively weighing .3% more at the poles is responsible for sealevel at the poles being 21km closer to the center of the earth than it is on the equator.
Apart from the one we're standing on? :)
... is 6378.5 kilometers, not 12756.3 as you have above. The correct values for the force on a 1kg mass on the surface are:
Earth: 9.785 N
New planet: 18.366 N
So the grandparent poster is correct, the surface gravity would be about 1.9 times that of Earth.
- 5.9x mass of earth is not a lot for like to handle. Remember, you get a lot more pressure from every side of your body (as oppose to only downward in gravity) say if you are in 1000m under water.
- Our earth will end the same way. The sun will expand into red giant, pushing earth away from its original orbit (with protons/solar wind and whathaveyounot), but still be close enough for a nice and even baking of the surface (and kill everyone on the planet I pressume).
We could maybe find ancient life on this planet!! Forget about Mars- to find life, THIS planet is WHERE we should be going next!
This is pretty simple. Surface gravity for spherically-symmetrical masses scales linearly with mass and inverse-square with radius. The mass makes gravity 7.5 times higher, while the radius would make it 4 times lower, for a total surface gravity of about 1.9G.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
There are many others: Pulsar timing, Astrometry, Gravitational microlensing, Transit method, Circumstellar disks, and ... Direct observation (courtesy of wikipedia
The Raven
Anybody intrested in a time-share there?
I'm going to guess there is no night and day. The plant is probably tidally locked.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
How do the religious fundamentalist zealots who wish to remove proven scientific theory, such as that of evolution, from textbooks react to a discovery such as this? Will its veracity be completely denied?
Cyric Zndovzny at your service.
Assume I was drunk when I posted this.
I have no access to the original article (yet).
The surface temperature and luminosity of the star can be determined spectroscopically. Given the radius of the planet's orbit (calculated), and the measurable stellar properties, one can estimate the energy incident on the planet (per sq. metre). The amount of incident energy will determine whether a gaseous planet, or terrestrial atmosphere, can exist. Too much heating and the average energy of atmospheric molecules exceeds the escape velocity (which is calculable from mass) of the planet. This is possibly the method used to determine that the mass must be rock rather than gas.
Having determined a rocky nature, the next step is to assume Earth-like composition and average density...this gives a radius.
It's also possible that tidal gravitational effects of the star at that distance preclude stability of a gaseous body of the calculated mass. Look up Roche limit.
An estimate, yes. A purely headline grabbing guess, probably not.
Patent litigation: A doctrine of Mutually Assured Destruction... in which everyone seems willing to push the button
That sounds all nice, but then the thought is supported only by freshman logics.
To prove this, one must calculate that (1) either radiative or kinetic evaporation (stripping) is effective in this environment (Remember, the magnetic field would make it slightly difficult to make the stripping of gas out of a planet); (2) the heating can be assumed based on blackbody estimate, yes, though nothing is ever that: black-body; also cooling can take place via radiation (and albedo matters, too, which we have no idea what).
I'm saying it's easy to speculate what it is; hell, it might be right at the end. But it's just because it's the simplest explanation (e.g., Occam's razor), it doesn't mean that the explanation must be right. Astronomers tend to fall into that trap too often. (but then this is Geoff Marcy, whom I know to be a very methodically careful man).
As for Roche limit, I don't have to look it up. It won't do you any good since this isn't a simple binary system.
Though, just to be fair to everyone, you *are* assuming that the density of the new planet is the same as Earth's. A perfectly reasonable assumption given this planet is meant to be "Earth-like", but worth flagging up all the same.
So, we get more and more data to support the view, that planetary systems are almost as common in the Universe as stars. Therefore the "fraction of stars which have planets" in the Drake Equation can be now assumed to be more close to 1 than 0. And that's good.
Have you seen the page on Space Food: http://www.universetoday.com/am/publish/mmm_food_m ars.html ? (you may need to close up the gap in mars in the url)
Here you can see the French plan to invade a peace-loving neighbourly planet, seed it with life-forms, and then eat them!
I had never thought b-list science fiction plots worthy of any consideration, but the French obviously do. They even proudly show a spoon-full of simulated dead Martian creatures (they suggest boiling them to death).
Uranus jokes were old when the solar system was still forming.
The text under one of the images states
In reality, astronomers do not know if the planet is rocky or gaseous, like Jupiter. The planet's temperature is at least a scorching 1,500 Celsius (2,700 Fahrenheit).
"Hi Bob, what time is it?"
"Quarter to Summer, Janine"
"OK, thanks Bob, Look I am off to have lunch, some summer berries I guess, I'll do those reports at half past Autumn ok?"
"No problem, just get them to me before I get snowed in my office again"
Orbits the star once every 48 earth-hours? Or Orbits the start once ever sol? (if its day is 182.51 days long, then its year wold be equal to hours if this is right)
Tum tee tum. Fly me to the moon and let me play among the stars, let me see what life is like on Gliese 876 and Gliese 875.
No doesn't have the ring to it.
#hostfile 0.0.0.0 primidi.com 0.0.0.0 www.primidi.com 0.0.0.0 radio.weblogs.com
This makes it the third planet known to orbit this star. The other two planets have orbits of 30 and 60 days. It's worth noting that Mercury orbits the sun every 88 days, so there are three planets in this system at distances well within the Sun-Mercury distance.
More extraordinary, is that this star is about 1/3 the mass of the sun, which would mean that these planets would have to be even closer to this star to orbit at that speed. More than likely, these planets all formed further from the star than they are now, but their orbits were unstable and are steadily spiraling into the star. It's entirely possible that there were several more planets before, but they're gone now.
"No problem. I have the capacity to do infinite work so long as you don't mind that my quality approaches zero."-Dilbert
THATS what im talkin bout'
It's still a bit hot right now - 200 degrees estimated surface temperature. That's not quite hot enough to ignite paper (we're talking celsius here), but still hotter'n New York this week. You'd have to get some serious soot in an atmosphere to cool it down!
:-P Maybe a colony ship going there could artificially support successively higher Gs for several generations...
But 2X gravity? We should be able to survive that...unless we were born on earth and had brittle bones and were getting on in years
OTOH, high gravity on means that the workers have a -50% penalty, at least until a Gravity Generator is built! If it's an Extra Rich planet, that's still ok!
--LWM
Actually, since the Earth itself is at a near fracture state and this new planet is of lower density (8 times Earth volume, only 5.9 times Earth mass) it must be much closer to fracture. Of course, orbitting it's sun every two days would also be inducing a massive tidal stress.
So long and thanks for all the fish . . . !!!
Geez, if there are planets like this one just 15 light years away (a grain of sand in universal terms, I think), imagine how many earth-like planets there are in the universe...
Signed,
Captain Obvious
The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
An alternative method is to look for eclipses of the planet passing in from its stars. About 5% of the planets have been discovered this way. One estimate is about one in two hundred stars have suitable orientations and plantary systems for this method, if one could observe them long enough. A @hundred megapixel space probe called Kepler might be launched around 2008 to observe light curves of several hundred thousand stars for several years. This might find dozens of eclipsing planets plus understand the abundance of planets.
Einstein didn't directly observe E=MC^2, he deduced it with mathmatics; but we dont argue against his have discovered special relativity. In fact there is a strong case to be made that a proof is better science than observation since to paraphrase my school physics teacher. Observation is constrained by the limits of human error whereas mathmatics is an absolute proof.
Note that 7.5 times earth's mass with twice earth's radius give a surface gravity of 7.5/2^2 or just slightly less than 1g. Might be a nice place to visit!
Except that out of those, only microlensing is likely to detect non-giant planets (orbiting non-pulsars) and it's based on random luck.
In practical terms, if you want to find earthlike planets, you use the doppler method.
Here's what I think the relevance of that planet is. It's not very far away from a light year standpoint, and yet it's "rocky". It's far too close to the star, with surface temps near 800F. If another planet was in that solar system, say one that supported humans, we can't see it. Yet.
That's just nearby. We found another planet just next door. That suggests the probability of another habitable planet for humans is, well... it has to be considered higher than it was before encountering this planet. We don't have any statistics as to the probability of a habitable planet forming around the different classes of stars, but there are trillions and trillions of planets. Too far to get to, perhaps, but the chances that they exist have to be considered greater than originally thought.
Wait, the formula is g = GM/r^2
Where; M = Mass of Earth, and r = radius of Earth
so 7.5*M = Mass of article's planet
and 2*r = Radius of article's planet
Finally:
Gravity of planet = G * 7.5*M/(2*r)^2
Which is what the original poster posted.
New g is =7.5/4 = 1.875 of earth. Livable for even us humans.
The beauty of comments like this lies in the fact that I am not smart enough to know if it's total bullshit you made up, or if you are a freaking genius.
DON'T MOD people as "informative" when they got their basic math completely off. Their equation gives ~4.592. Which itself is completely wrong! But I guess if you are going to mess up, you might as well make sure you really did mess up. The really first poster was right. It is roughly ~1.9 times that of earth.
Muh bdu fwuma buw fwu dluhd bwuaha!
:o)
Bonus points to anyone who can tell which movie it came from
"Interesting, but method is flawwed"
Flawed for what? Your personal goal of finding "earth-like" planets?
A decade and a half ago, there was no measurable evidence--direct or indirect--of any planet around other stars. The goal has been to discover planets and then study solar systems. It's going pretty well, it seems. Finding earth-like planets, although neat and great for PR, is not going to be the primary short-term goal of these studies. It takes better and better instruments, which you have to prove are going to be viable. It also takes a long time collecting lots of good data and time to develop good models (that require the long-term good data to constrain them).
Strangely, your intuition is right about a lot of the "arguments" you make, but your conclusion is bizarre. Astronomers have ideas about how to search for planets, but those methods are still being refined, will get better with better instrumentation, and will get better with more time. But a few of these basic ideas have been pretty well established as being quite effective.
The time must surely be approaching for someone to start R&D on space probes that don't take 20+ years to exit the solar system and can reach significant distances in less time, with onboard sensors to send back better information from "up close."
Sure, it might take a relatively long time for the probe to get there (not in the maker's lifetime) and information coming back would be delayed (until we learn how to do sub-space comms like in all sci-fi movies) but surely we can start thinking ahead...
We could even start out small and send them to stars that are much closer - like Alpha Centauri.
It takes a very long time for something to become tidally locked. I think the larger an object is, the longer this can take. Maybe it still rotates, but slowly, like Crematoria from Riddick.
This planet is large, so more noticeable by less than sufficient detection equipment, and it orbits its star every two days, so the likelyhood of occlusions is statistically large. Not msntioned is that its orbit is mostly planar to our viewing direction, the alternative of which is no occlusion observation would be possible. We are not detecting typical planets, but rather we are detecting those with a greater statistical likelyhood of being found by our primitive equipment. It would be wrong to confuse these issues. This is with the occlusion method. Occluded images that are extremely fuzzy will be percieved to be gas giants, and those that are sharper will be judged to be 'probably rocky'. The gray areas here are huge. The wobble method is more problematical. The perceived wobble of a star is caused by motions induced in the star arising from forces exerted by the centroid in three dimensions of all the planetary masses of any size acting as one gravitational force. Calculus and differential equations must be used to calculate this from a known system. We barely have a handle on how to calculate this from inside our own system where we at least have a clue where our own system major masses are, how dense they are, and how they move. To reverse calculate this for a foreign system from a great distance and not knowing anything about it is to suddenly discover huge planets is very odd orbits. That is why so many unlikely 'Jupiters' have been found. They are not 'Jupiters' at all, but rather the moving location of the locii of all that systems planetary masses as that locus orbits its central star. Some budding mathematically inclined slashdotter should do this calc for our own system, and he/she would find that from, say, an observer on a planet orbiting Epsilon Eridani, our Terran system would appear to have a large 'Jupiter' orbiting our star maybe once every 13 years or so as our own planetary centroidal locus of gravitational force moves its virtual location around our central star.......if he/she has equipment like ours. BOFTTOM LINE: Planetary systems like ours will be found to be the common mundane findings whenever a true system survey of a new system is undertaken with interstellarly sufficient equipment.
If you live in a swamp, like the dinosaurs, the odds of dying from falling over go down a lot.
:-)
Landing your head in a clump of soft mud isn't as likely to be fatal as smashing it on a rock.
If you live on a mountain, or other rocky place, there are more rocks around, and you can die from a fall onto rock easier than fall onto mud.
So, enviroment matters a bit, too. But you're quite right, the risk of hitting your head isn't that big to begin with. How often have you fallen headfirst towards the ground in your adult life (not counting sports like diving?)
I count exactly once, rollerblading. Both my toes hit a lip at the same time, and tipped me straight down on a downhill slope. Fortunately, I broke my fall with my arms as I landed. I thanked my martial arts instructor profusely next time I got back to class.
Master of Orion 2 is the only game that I've played every month that I've owned it. (1997 or so)
Better than Civ, better than SC2K, better than Scorch, better than Nethack, better than Starcraft, better than any first person shooter (at least for solo play).
I have Master of Orion (original) is good too.
Master of Orion 3 is very bad. It is literally, purposely unplayable.
Exam 4/C again. Maybe I'll do better this time.
How many fathoms in a vast?
Or was it vasts per sennight?
Exam 4/C again. Maybe I'll do better this time.
"Also, the wobble can be caused by assymetrical mass distribution within the star itself. "
I've never heard of that kind of thing before.
Does our sun have assymetrical mass distribution?
Wouldn't the same principle that makes the star roundish keep the mass symetrically distributed?
Aren't stars fluid enough that their mass would self-distribute to symetry of shape?
Anyway, possible or not, it's still interesting to think about a star with asymetric mass.
(Of course the mass of the star would be symetric around it's center of mass, by definition.)
Exam 4/C again. Maybe I'll do better this time.
Perhaps I am crazy, but last time I checked well over 2/3 of the earth's surface was completely untouched. Further, that untouched area can be extended in either direction for at least a mile (if not more). Room is not a problem for humans and never will. Hell, even surface area is not an issue. Even if surface area was an issue, given sufficent power, we are more then capable to farming underground.
Personally, if I had the choice between living on a hostile planet with an unbreathable atmosphere or floating blissfully above or below the ocean with more air then I could ever possibly breath right above me, I would take the planet with abundent water, air, and a climate suitable for humans.
Further, even if we were insane enough to decide to move the population off planet instead of just filling in the unimaginable volume of our very own planet, the real issue would be moving that many people, not getting them there in one piece. If the population is 6 billion strong and grows at 1% per year, you would need to move over a million people a week off the planet just to keep zero population growth.
We both vote to shoot all idiots who think there is some static utopian version of Earth
You "vote" to shoot people who you think are misinformed? Was that on the ballot? Oh, I get it -- you're telling us what kind of government you'd like. That was already starkly obvious owing to the authoritarian myopia of the people you really have voted for. Thanks for checking in though.
"Fundamentalism" isn't about divine morality. It's about human authority.
You can tell other things by looking for wobbles. You can look for drunk people by seeing if they wobble.
So this wobble method, are they looking for drunk planets? If the planet's speech is slurred, then we know for sure. Rocky planet, more like vodka on the rocks planet.
Rock on! Here's a toast to our hot (200-300 C) new cousin.
Paul
... the preferred pronunciation sounds more like urine-us than your-anus. Listen: uranus.wav Not nearly as funny to adolescents.
Win a signed Stephen Carpenter ESP Guitar from the Deftones: http://def-tag.com/?r=0008781
Earth has lost its mantle (har har) as the largest rocky planet in the known universe, but it's still the MOST DENSE!
Plus ça change, plus c'est la même chose.
Re-reading my reference they're basing their stats from 125 countries (pop. > 1M), not saying there are now 125.. all I could get out of it was a prediction of around ~30 countries by 2025.
It seems like every single planet they have discovered they have branded as earthlike. So now when they do find something earthlike (with oceans of water and not boiling sulfuric acid or something), it will be ignored by people as so much wolf-calling.
Other planets were gas giants, but they were called "Earthlike." This one sounds like it is close enough to its star that the surface could melt lead. Not exactly a good place to set up a tent.
"Earthlike planet" seems to simply mean "planet" the way they use it. Had they discovered a floating ice cube beyond Pluto, they would have called that "the next planet." If there is a speck flying around nearby, they call it a killer asteroid, and if a killer asteroid passes by without crashing they say "whew, that was close, we didn't see that until it passed by."
Reminds me of:
Noise proves nothing. Often a hen who has merely laid an egg cackles as if she laid an asteroid. --Mark Twain
But this is more than sufficient that if there were intelligent life (fabulously unlikely) then they would quickly notice that things were a few percent lighter at night than during the day.
Sounds like a good premise for a sci-fi story: a civilization where all major construction is performed at night, because it's cheaper.
(scribbles into notebook)
Thanks!
What part of "shall not be infringed" is so hard to understand?