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Planetary System Similar to Sol
sgtwilko writes "The BBC News site has an article about how astronomers have found several new planets including some that have a similar distribution to our own Solar System. They are finding planetary systems that are more and more like the one in which the Earth resides. It's only a matter of time until the Terrestrial Planet Finder program gets going and finds another Earth." There's another story on space.com. Update: 06/13 21:51 GMT by M : Space News and Wired have stories as well, with spiffy graphics and artists' renderings and so on.
i don't get the thrust of the article focusing on finding earth-sized planets. is there some theory that necessitates a planet be our size to foster life? if so, why?
(here comes the (-1, Ignorant). bring it on.)
go get it
They have also found the smallest exoplanet yet. It is only 40 times more massive than Earth.
The size of the planet isn't really the issue though,
Detecting Earth-sized planets is probably not possible using current ground-based techniques. That will have to wait for a new generation of satellite observatories, due in the next decade.
The important part is
Calculations made by Greg Laughlin of the University of California at Santa Cruz show that an Earth-sized planet could survive in a stable orbit between the two gas giants.
This of course doesn't mean that we found anything only that when we are able to look for earth-like planets this is our best bet for hitting the jackpot.
I stole this Sig
A quote from the CNN article (which seems to be a bit more fleshed out) I didn't see in either of the ones listed at the top:
"We haven't found an exact solar system analog, which would have a circular orbit and a mass closer to that of Jupiter. But this shows we are getting close," said Paul Butler, another member of the planet-hunting team.
But the orbit of the Jupiter-like planet is stable enough to foster a benign, life-friendly environment in the inner solar orbit, Fischer said.
Dark Nexus
"Sanity is calming, but madness is more interesting."
On the other hand, my uncle said:
I completely agree with both, Spock and my uncle.
This sig is a true statement, but I cannot prove it.
This is not a troll -- I'm genuinely very curious.
What do Christians think about stories like this? I ask becuase, in discussions with Christians, I've heard Christians tell me that there is no intelligent life on other planets. This was usually in response to my questions like, "Did Jesus die for aliens on other planets?" Perhaps a silly question for me to ask, but the "There is no intelligent life on other planets" was not an uncommon belief among the Christians I've met.
So I've often wondered what Christians (particularly Christian nerds, who are probably significantly more friendly to science than some of the Christians I've met) think when stories like thit surface and hint at the possibility of finding other "Earth-like" planets that may have intelligent life on them.
Thoughts?
I don't make the rules. I just make fun of them.
What bothers me about this is that while there is a quick mention of "formation models," most of the discussion of the potential existence of a terrestrial planet seemed focused on the stability of an orbit in the present configuration. In fact, it isn't clear to me that they've even considered the formation processes at all. (To be honest, I get the opposite sense.)
Why does this bother me, you ask? Because an orbit at 1 AU might be stable NOW, but if you have a giant planet migrating in through the inner solar system to an 15-day orbit, it'll wreck jolly hell with any planets it passes. The migration is slow enough that you are almost guaranteed a close-enounter of some kind. Once a Earth-sized planet gets near a giant planet, the orbit is in the very least highly perturbed. Odds are fair that it could be ejected altogher or will collide with the giant planet and be effectly lost. But even if it isn't, the eccentricity is probably going to be increases substantially. A planet that changes its distance from its star radically over a year is unlikely to be habitable, if you believe current models.
How likely is that, for any given star?
It's more likely than you might think. It has to do with conservation of angular momentum and it's the planets and even the moons in our solar system are all within a few degrees of the same plane.
Sure there are exceptions, but the chances of seeing a solar system on edge is considerably better than whatever it would be if they were just randomly distributed.
That's not exactly true: in our case, the Sun pushed (light pressure, and another effect I can't think of the name of...) or ate all of the light gaseous material inside the asteroid belt. At least, it did, viewing it from 6 or so billion years later.
Now, the next problem is that we do NOT know how these giant planets near their star formed. People suggest that the planets migrated inwards, which would make an Earth-sized planet unlikely. However, there are some suggestions that the gas giants CAN form that close to their star. In fact, I don't think that we would even KNOW if there had previously been a gas giant inside Mercury's orbit that has long since been devoured by the Sun. Thus we could be looking at a Sol-like system, just much earlier in formation.
It should be noted that Jupiter has some influence on Earth - but it's very minor. Venus has significantly more influence (Venus's rotation is actually in a resonance with Earth's orbit).
A planet that close to the Sun orbiting that quickly would, from Earth's (1AU) point of view, just look like an increase in the Sun's mass. Work out the differential force: With a differential distance swing of 1/40 AU, but the distance going as the cube, it's really going to be quite minor: about 1/200th the tidal force of the Sun, which is less than that of the Moon. It's not like the Moon's influence seriously screws up the planet. (Note that I'm talking about the differential force of the swing of the inner planet: that is, how much does the tug of the inner planet really change from Earth's point of view? Not much at all).
Gravitational perturbations are due to differential gravitational forces, and the forces on Earth due to a planet orbiting at 0.025 AU are trivial. As for asteroid components, it depends on how the planet formed, which we don't understand yet. If it formed far out, and moved in, then yes, it would be a menace. But if it formed close in, it's extremely unlikely to cause any "asteroid bombardment" or anything like that.
Keep in mind that you could consider a slight "bulge" in the sun to be a "giant planet" orbiting the Sun obscenely quick: if it was likely that this would disturb the Earth, the Earth would be in very bad shape: bubbles of different densities appear on the Sun all the time. The differential force just isn't that great.
Should we look there first? Yes. It's an IDEAL target, actually! It's a planetary system where both standard Sol planetary formation processes are occuring, and this "weird' giant planet stuff is happening. If it isn't the first stop for the TPF, I'd be amazed. That's a system worth studying. And would anyone be surprised to see an Earth like planet show up there? Not likely.
By now, I am readily convinced that there is other life in the universe. In fact, it seems that odds are greater that there isn't life in the universe.
But if I'm like most anyone else, the possibility of life on the western spiral of the Andromeda Galaxy just isn't useful. Its simply too far. We would never recieve a radio transmission from there and its too far to travel.
First, lets assume Einstein is correct and we can not travel faster than the speed of light. In addition, lets rid our minds of all this science-fiction crap like wormholes and warp-drive. While I am naive, I'm not *that* naive.
Lets take the nearest star. I've heard it is 4.3 light years away. That means a radio transmission originating their takes 4.3 years to travel here. Honestly, we could live with that. Of course that is not only assuming that that civilization has developed technology, but it also assumes that they haven't been exinct by some means.
But, we're pretty sure there isn't a planetary system around proxima centauri. So we have to look farther out. But how long are we willing to wait for a round of communication from us to them? One hundred years? One thousand years? A hundred-thousand years?
Okay, as a second consideration, how long does a civilization last once it discovers radio? We've only had radio technology for a relatively little time. How much longer will we continue to exist? Take HG Wells Time Machine. Will we unlearn our technology and instead progress towards a native happiness? What about other civilizations?
In all, what are the odds that not only life exists in the universe, but that it is close enough and that it is in their technological prime?
I'd fashion that the odds are astronomical against us.