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Transit Method Reveals Many Extrasolar Planets
Posted by
ScuttleMonkey
on Mon Jun 11, 2007 01:02 PM
from the through-the-looking-glass dept.
from the through-the-looking-glass dept.
eldavojohn writes "You might recall not too long ago the first photo of an extra solar planet or, more recently, the mapping & speculation on these planets that lie outside our own solar system. Long since those first few spotted in the 90s, we're now starting to find them in droves due to the popularity of a method that relies on the planet passing directly between the viewer on earth and the star that it orbits. Be sure to check out Space.com's list of the most interesting extra-solar planets. Will we ever find Earth 2.0 candidates?"
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Extrasolar Planet Could Harbor Life 308 comments
BlueMorpho writes with a link to a Space.com article about a recently discovered extrasolar planet that may be able to harbor 'life as we know it.' Orbiting around the star Gliese 581 is a small rocky ball that might have the same liquid ocean and drifting continent configuration we're familiar with. The find may be unique in all of space exploration as this planet appears to be within a habitable band of temperatures for life, and is categorically not a gas giant. "The bottom line is exciting ...The conditions for life could be there, but is life itself? As yet, there's no way to know unless the planet has spawned beings that are at least as clever as we are. As part of the SETI Institute's Project Phoenix, we twice aimed large antennas in the direction of Gliese 581, hoping to pick up a signal that would bespeak technology ... Neither search turned up a signal."
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Pegs that variable in the Fermi equation... (Score:5, Insightful)
Re: (Score:2, Interesting)
RonB
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Re:Pegs that variable in the Fermi equation... (Score:5, Funny)
Quite the opposite actually...
"You cannot prove that I exist", says God, "For Proof denies faith, and without faith I am nothing!"
"Ah", says man, "But the planets lining up nicely like that so that we can see them is a dead give away isn't it. It proves you exist, and therefore by your own logic you don't. QED"
"Oh bugger I hadn't thought of that" says God and disappears in a puff of logic.
Sorry Mr Adams.
Parent
Re: (Score:3, Insightful)
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Um, you do know that the Universe is flat, right? Just like Earth. :)
perhaps not so lucky (Score:5, Insightful)
Given all that then it's not too surprising that there be a preference for this favorable occultation geometry.
Finally I note that we are not really interested in planets that don't rotate in their orbital plane since otherwise they'd be roastingly hot on one side and freezing on the other.
Parent
Re: (Score:3, Interesting)
Yes, but wouldn't there be a certain ring that is exactly 70 degrees? Also, you'd have an endless supply of geothermal energy. The hot-as-lava side could double as an incinerator--no trash problems. Obviously terraforming would be impossible but I'd think you could establish a permanent colony there.
Re:perhaps not so lucky (Score:5, Insightful)
I'm no expert, but I'd be willing to bet that what you'd really get is a ring that fluctuates violently between the hot and cold extremes of the two sides of the planet and is constantly bombarded by gigantic storms. I mean we're basically talking about a permanent clash between hot and cold weather fronts.
Huge temperature deltas do not result in nice smooth gradients between them.
Parent
Re:perhaps not so lucky (Score:4, Interesting)
Parent
Re:perhaps not so lucky (Score:5, Informative)
"Finally I note that we are not really interested in planets that don't rotate in their orbital plane since otherwise they'd be roastingly hot on one side and freezing on the other."
The rotation of the planet has nothing to do with the detection of planets in this method, only the orbit determines the ability to detect it. So while some planets may or may not be rotating on the correct axis to support multiple seasons, it isn't accounted for in this type of study because they can't detect this with the transient method.
Also, there are actually a large variation of planes that can be detected with this method. Imagine our solar system as a disk. Then imaging looking at it from the top view. This view does not allow the planet detection using the transient method. However, angle your view down until you can see just one of the planets cross over the sun. From this angle on, and twisted up to 360 degrees, is where this transient method works. So actually, there are many planes of orbit which can be used to detect planets with this method. And assuming that a percentage of these planets are within the habitable distance from their star, and that a percentage of these rotate on a reasonable axis, then they could contain life. But nothing in these studies is determining that any of this is the case. Right now they are just looking for ANY planets. so we can detect extrasolar planets even if their orbital planes are perpendicular to the galactic disk, so long as they are close to parallel to our viewing line of site. With this in mind, you can imagine that if you can view stars in our galaxy from 360 degrees around our planet, that we would be able to detect every orbital plane angle available in the galaxy, depending on which direction we are looking from the earth. So while we can't see all of them, we can see a very large subset of them with this method.
Also, the reason that all the planets in the solar system follow close to same typical plane of orbit is because of the way solar systems form. They start as a gaseous body collapsing. As the rotation of the gas nears closer and closer to the center of the nebula, the rotational inertia causes the forming of a disk due to inertia. The same thing happens to drag car tires when they spin fast (they turn more disk-like). From this disk-like nebula the planets form. The center typically ends up with something larger than a gas giant (the sun, or a couple of suns) and the other planets turn into gas giants (Jupiter) or solid planets (i forgot the name, but they gain gravitational pull and pull in particles from the nebular disk)
So this is why the planets are all in one plane of orbit. If all star systems are formed in this general method (something that is assumed) then it is fairly easy to say that they should all be in a single plane. But each system does not necessarily have to be in the same plane relative to each other just because they are in the same galaxy. Each nebula forms independently and collapses typically from an outside force, but not necessarily on the same rotational plane.
Also, the planets have their own disks associated with them. The moons and rings of Uranus and Saturn and Jupiter follow different planes. They don't necessarily need to follow the same plane as the solar system. This is because each of those planets also formed independently of each other. The spin of those depends on the angular momentum of the local mass as it formed, which would be different than the parent nebular disk especially when you take into account collisions of forming bodies. The same could be said to happen on the galaxy level, if you compare the galaxy formation to solar system formation.
These are just my points of view of what I have studied. Many people will have different points of view formed from the same observations.
Parent
Re:perhaps not so lucky (Score:4, Interesting)
They don't. See http://curious.astro.cornell.edu/question.php?num
Our own Solar system is not at all aligned with the galaxy. If it were, the milky way would appear more east-west in the night sky, especially during the equinox.
Parent
Re: (Score:3, Interesting)
Or, a naive argument from astrophysics (IANA astrophysicist, although I am a physicist): Perhaps the disk of a new-formed star is typically rather thin (in the direction perpendicular to the ecliptic). Then material undergoing gravitational accretion to form planets would all c
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Really? Then why'd he go and bury all of those dinosaur bones and radioisotopes to test our faith?
Will we ever find Earth 2.0 candidates? (Score:3)
Re:Will we ever find Earth 2.0 candidates? (Score:4, Interesting)
Parent
Re:Will we ever find Earth 2.0 candidates? (Score:5, Funny)
I certainly hope it contains the same easy-to use ergonomic AJAX functionality as Web 2.0...I hate having to reload an entire Earth page every time I want to do something...
Parent
Ummm....It's The Wobble Method That's Tops (Score:5, Informative)
WOOT!!! Earth 2.0 (Score:2)
ROCK ON!
2 cents,
QueenB.
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Why would anyone look for Earth 2 again? (Score:2)
Yes (Score:4, Interesting)
Of course; space is big and there are bound to be tons of great planets out there. I just hope there is no one already living on our soon to be discovered new colony planet so we can move in quicker.
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Barring that, hopefully we can develop some kickass motherships and tripod walkers.
Will we ever find Earth 2.0 candidates? (Score:2)
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Bowman 2.0 (Score:5, Funny)
Re:Bowman 2.0 (Score:4, Funny)
Parent
Will we ever find Earth 2.0 candidates? (Score:3, Funny)
Earth 2.0 candidates (Score:2, Offtopic)
Version (Score:3, Funny)
How about making the current one stable first?
That's not how the number system works (Score:4, Funny)
Parent
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The current one is fine. It was here before us, and will be here long after us.
How about we kick condesending butts like your's into the sun?
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Extra Solar (Score:2, Funny)
I mean "extra salt" = more salt, right ?
so we can ... (Score:3, Funny)
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now that we can find them (Score:3, Interesting)
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If you've read stuff by Larry Niven, what started everything was probes. And then hibernation ships that caught up to and passed some probes by.
How lo
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Aside from the lifetimes of "Are we there yet?", you know the offspring would just take the fact that they're on an interstellar voyage for granted, and they wouldn't even appreciate the arrival. "This is the planet my great grandfather wanted to visit," they'd say. "Let's check out Earth."
I cannot be alone (Score:3, Funny)
...when I say if it is actually called "Earth 2.0" that I would seek Kevorkian's "assistance." (Joking, of course.) The moniker is used way too much! Instead, I feel we should call the planet "Godzilla" so it would be entertaining to hear people scream its name in excitement upon viewing it for the first time.
Updated stats (Score:2, Interesting)
I recommend going to the top-10 list found
Earth 2.0? (Score:2)
How about "earth-like planets"? Or "planets like ours"?
Honestly... phrases like "earth 2.0" and "web 2.0" (not to mention WiFi, which really ought to be pronounced "whiffy") make me wonder about the collective intelligence of the technically inclined.
Space.com... the worst website in the universe? (Score:3, Insightful)
God, what a mess the "Top 10 Exoplanets" site is! Bright orange background that is absolutely physically painful to look at, requires 10 click-throughs to read the whole article (when each page has about a paragraph of text), the text itself is in little iframes that require you to scroll to get past the first few sentences - and don't get me started about the content (what little there is). If you haven't visited it... don't.
Looking for Earth 2.0? (Score:3, Interesting)
Well... (Score:3, Insightful)
I'm not sure how serious you're being (Score:5, Interesting)
Parent
Re: (Score:2)
Re: (Score:3, Informative)
More precisely, the new definition [iau.org] does not attempt to classify extra-solar bodies as either planets or not-planets. It starts out like this (emphasis mine):
The IAU's working group on extra-solar planets [ciw.edu] does offer a working definition, subject to change. [ciw.edu] See Wikipedia [wikipedia.org] for more details. See also rogue planets. [wikipedia.org]