Jupiter Destroyed 'Super-Earths' In Our Early Solar System 69
sciencehabit writes: If Jupiter and Saturn hadn't formed where they did—and at the sizes they did—as the disk of dust and gas around our sun coalesced, then our solar system would be a very different and possibly more hostile place, new research suggests (abstract). Computer models reveal that in the solar system's first 3 million years or so, gravitational interactions with Jupiter, Saturn, and the gas in the protoplanetary disk would have driven super-Earth–sized planets closer to the sun and into increasingly elliptical orbits. In such paths, a cascade of collisions would have blasted any orbs present there into ever smaller bits, which in turn would have been slowed by the interplanetary equivalent of atmospheric drag and eventually plunged into the sun. As Jupiter retreated from its closest approach to the sun, it left behind the mostly rocky remnants that later coalesced into our solar system's inner planets, including Earth.
But (Score:2)
So how come that happened in our solar system, but not in the many other exo-planetary systems that we have found recently/
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Odin the All-Father.
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God does play dice with the universe.
Or at least, marbles.
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God does play dice with the universe.
Or at least, marbles.
"God does not play dice with the universe; He plays an ineffable game of His own devising, which might be compared, from the perspective of any of the other players(everyone else), to being involved in an obscure and complex version of poker in a pitch-dark room, with blank cards, for infinite stakes, with a Dealer who won't tell you the rules, and who smiles all the time" ---Terry Pratchett.
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God does play dice with the universe.
Or at least, marbles.
As long as it's not Tiddlywinks...
...because (Score:2)
...if it didn't we wouldn't be here to talk about it.
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I've always disliked this non-answer. Imagine you were in the "Hunger Games" and you won. Someone then asks you, "How did you survive?" You then answer, "If I didn't, I wouldn't be able to answer you." Everyone would agree that this does not answer the question.
Re:But (Score:4, Insightful)
Because it's a big-ass sky with lots of solar systems.
No, seriously. We used to think planets around stars would be rare. Now we know otherwise.
Think of it like a lava lamp ... it happens according to knowable rules. But it doesn't happen the same way every time.
What we keep seeing is a stunning diversity in how individual solar systems form. Not some uniform composition.
I'm no astronomer, but this is more about there simply being a huge amount of possible combinations, in a vast collection of instances.
Re:But (Score:5, Informative)
So how come that happened in our solar system, but not in the many other exo-planetary systems that we have found recently/
Selection bias. Our planet detection technology is still very primitive. We have found lots of big, hot planets orbiting very close to stars, not because they are common, but because they are easy to detect.
Re:But (Score:4, Informative)
Easier to Detect. The easiest to detect is great big gas giants nearly the size of their star orbiting very closely (hot gas giants). Those were the first discovered and comprise the majority of systems discovered so far because the bigger the planet and the closer to the star the easier it is to infer with the current detection techniques. We've never actually imaged one of these worlds, we've only inferred their presence for example by rhythmic flickering from a planet passing in front of the star.
As someone (I can't recall who) said, trying to find planets is like trying to see a mosquito in front of a 10,000 watt light bulb from a football field away. In other words is pretty difficult, in fact so difficult we can only find planets through inferred methods, not direct imaging. Unless we can find a way to completely block all the light from the star without blocking anything illuminated by the star and thousands of times more magnification (say a focal length of half the solar system) we aren't going to image a planet like earth. Space is really really big and the distance between stars so great that even when two galaxies collide there is very little chance of two stars impacting.
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Simulations suggest that it is very sensitive to exactly where the gas giants form and the density of different parts of the dust cloud. Small changes in initial conditions mean that they may head in and stay there -- hot Jupiters; never head in at all -- hot super-Earths; or do what ours did and dive in and then out.
Thanks, Jupiter (Score:2)
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Penalty 374.42.7a (Score:3, Funny)
Jupiter and Saturn shall be sentenced to death for deviating from the approved Stellar System Standards, which has resulted in the formation of humans and other pestilences.
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Is your name T-Rex?
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I recently had a dream where the Sun disappeared, Would that have any effect on earth?
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Let me tell you, you do not want to be anywhere nearby when a new star is igniting. It would be many thousands of years while it adjusts to it's new condition and settles down.
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another kind of selection bias (Score:5, Insightful)
So, we're looking for other civilizations, haven't found any, even though we estimate that life should be common. After all, if it happened here it should be able to happen in a lot more places.
But perhaps the set of circumstances that would create an environment that lasted long enough for life to be created and evolve to this point are wildly, vanishingly improbable. Perhaps the only reason we think it should have happened lots of other places is that we are the ones doing the looking, and we don't realize just how rare we actually are.
But that's a little depressing.
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We're not genuinely looking for other civilizations, because we don't have the capacity to look for that yet. We can listen for what would have to be absurdly strong radio signals, but that's not really looking. We can't even check an exo-Earth's atmosphere for oxygen yet, let alone signs of civilization.
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The rarity of intelligent life is up to debate, sure, but I think you're missing just how insanely huge the universe is and how many stars are in it.
It's highly unlikely (unless our understanding of the universe is completely off-base and practical FTL travel is possible) that we'll ever encounter extraterrestrials - remember, there's not just a lot of space for them to be in but a lot of time, too - but the probability of Earth being the only place where life exists is small enough to be indistiguishable f
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Agreed, agreed. "Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is."
The vastness of space actually counts against us in this particular case, I think. The stars, especially out in the backwaters of the galaxy like us, are fairly distant from each other. I agree that as numbers increase, the chances of anything happening, no matter how unlikely, tend to approach certainty. But if as I suspect we're radically off on how likely it is for civilization to happen,
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Note that if the odds were one trillion to one against, then we could reasonably expect 30 BILLION civilzations in the observable Universe.
Of course, those odds
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There's life and then there's intelligent life.
I'm sure life is out there somewhere. Might even be in other parts of our solar system, completely undetected.
Intelligent life, on the other hand, may not be so easy to come by. For starters, intelligent life requires a certain level of sophistication in the life form. I.e., you can't have intelligent life without a certain level of complexity. Even something as "dumb" as a roundworm is incredibly complex.
Complexity requires stability. Imagine being bombarded b
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> Imagine being bombarded by quasars and blasted by supernova. Life is very possible in that environment, but it would be equally difficult for any life form to organize into something more complex than bits of matter capable of replication.
I've been thinking of this point in particular, and I suspect that if intelligent life happens at all (other than us) it's probably most likely (or least unlikely) out on the edges of a galaxy, where low density of stars vs empty space reduces the odds of nearby super
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Over time we seem to be generally learning that our planet is rather unique in terms of our moon size, formation steps, and specific position in the "right kind" of galaxy per heavier elements and stellar explosion danger.
However, the flip side is that we've been learning how tenacious and flexible life is.
Thus, while matches to our particular circumstances may be rare, there may also be more than one path to sophisticated life.
For example, large Earth-sized moons of gas giants, oceans of mid-sized gas gian
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Earth-size moons of gas giants are definitely a possibility. I think we've already found gas giants in the "goldilocks zone". But I thought I read recently (maybe in Slashdot?) that although rocky planets orbiting close enough to red dwarfs to have liquid water might be fairly common, there was some other reason why life was unlikely in that scenario. I don't remember the details, though. Radiation, perhaps?
Poor Krypton (Score:2)
Ifs and buts (Score:1)
If worms had machine guns, birds wouldn't fuck with them.
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Is that you Dr. Evil?
Velicovsky (Score:2)
I don't buy it (Score:2)
This paper, and its conclusion seems remarkably premature.
The study starts with the assertion "The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. "
That's a pretty substantial, definitive statement right there. Yet, two of the very basic rules of statistical analysis are collection bias and contextual sample size.
In reverse order, then, first we're
Not new, but new insight in our solar system! (Score:2)
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The solar system consists of Jupiter plus debris (Score:3)
- Isaac Asimov.