Slashdot Mirror
Killer Asteroids Are Good For Life
Hugh Pickens writes "NASA reports that according to a study by Rebecca Martin and Mario Livio asteroid collisions may have provided a boost to the birth and evolution of complex life on earth delivering water and organic compounds to the early Earth and accelerating the rate of biological evolution with occasional impacts to disrupt a planet's environment to the point where species must try new adaptation strategies. 'Too many asteroids, and you've got an unrelenting cosmic shooting gallery, raining fiery death from above,' writes Fraser Cain. 'Too few asteroids, and complex life might not get the raw material it needs to get rolling. Life never gets that opportunity to really shake things up and evolve into more complex forms.' Martin and Livio suggest that the location of an asteroid belt relative to a Jupiter-like planet is not an accident. The asteroid belt in our solar system, located between Mars and Jupiter, is a region of millions of space rocks that sits near the 'snow line,' which marks the border of a cold region where volatile material such as water ice are far enough from the sun to remain intact. 'To have such ideal conditions you need a giant planet like Jupiter that is just outside the asteroid belt [and] that migrated a little bit, but not through the belt,' Livio explains. 'If a large planet like Jupiter migrates through the belt, it would scatter the material. If, on the other hand, a large planet did not migrate at all, that, too, is not good because the asteroid belt would be too massive. There would be so much bombardment from asteroids that life may never evolve.'"
This is nice, but it is entirely speculation. There really isn't enough data to make a conclusion.
http://www.geoffreylandis.com
...full of advanced life forms...
But not as we know it, Jim
It was perhaps great for life back in the old days a couple billion years ago. But it wouldn't be very good for us today. Can we not have any more mass extinction events, please?
Anyway, we're doing a pretty fair job of causing our own mass extinction. Nuclear war, tailored viruses, nano-machines run amock, artificial intelligence that wants us gone. Yup, lots of chances to do ourselves in and give the Earth a chance to start over.
it's = "it is"; its = possessive. E.g., it's flapping its wings.
It is amazing how little we know about the universe. Not amazing in terms of "why don't we know this stuff", but amazing in terms of "there is so much to learn that it makes what we know seem infinitesimal."
Logic and what we know already point to a universe filled with intelligent life or at least life. Yet we seem so all alone. Are we the first? Are we in a universe filled with life and cannot detect it? Has this universe been abandoned by all the more advanced life forms and we're one of the few left? Are we in a zoo?
All of these questions, and we only have speculation for answers. I'd expect to have some answers to these question in the next generation or two. We're detecting planets at an accelerating rate and are getting to discover smaller planets now that Kepler has had enough time to get enough transits for the further away planets. Our detection of radio waves ability is improving and we now have better targets to try out.
While we may not have all the answers, I would expect by 2050 to know how common life is, but part of me wonders if we haven't detected intelligent life by then if we are not truly alone in this galaxy. I shudder to think that might be true, but it is a real possibility. We live in exciting times, and I thank those that have made missions like Kepler possible.
-- MyLongNickName
Basically, intelligent life can only evolve under circumstances identical to the way we evolved.
"100 percent of the cases where we know life evolved, these circumstances prevailed. Therefore..."
Killer asteroids are good to life that might emerge after the collision. But if you poll the existing life on the planet? meh! Its popularity is going to be very very bad.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
"Snowline"-based conjectures actually postulate that Jupiter was formed exactly because of its location on the snowline: since this snowline has to be a sharp boundary(1), a locally-enhanced density area, radially symmetric around the Sun(2), is created and collapses into a massive planet because it rapidly accretes material(3) from its neighborhood.
I have seen a lot of hand-waving used to fill in the gaps (note: "hand-waving": (idiomatic) Discussion or argumentation involving approximation, vagueness, educated guessing, or the attempt to explain or excuse vagaries) on where and when a gas giant actually forms in a snowline, and how exactly planets 'migrate'.
(1) sharp boundaries may not be as common as you think: there is only a handful of computer models that actually take into account the three-dimensional structure of the accretion disk (proto-planetary disk, a very computationally expensive problem) and lots of physics are lost in 2D simplifications.
(3) Fairly recent observations have shown that complex organic molecules are present in Giant Molecular Cloud structures, long preceding the formation of any star or planet. The mechanism of their creation and their distribution is mostly unknown, and an active area of research, as of course is the formation of planetary systems. Hand-waving has not produced any robust results as of yet. Computer modeling, on the other hand, looks more promising.
The three laws of thermodynamics:(1) You can't win. (2) You can't break even. (3) You can't even quit.
So - intelligent life is actually made up of real bits of panther then? Fascinating!