Kepler-36's 'Odd Couple' Defy Planet Formation Theories 70
astroengine writes "The two planets circling Kepler-36, a sun-like star in its senior years, are as different as Earth and Neptune. But unlike the hundreds of millions of miles that separate our solar system's rocky worlds from its gas giants, Kepler-36's brood come as close as 1.2 million miles (1.9 million kilometers, or 0.01 AU) from one another — about five times the distance between Earth and the moon. This is yet another weird exoplanetary star system that defies conventional wisdom when it comes to planetary formation theories. 'The weirder they are, the more scientifically interesting they are,' Steve Howell, deputy project scientist with NASA's Kepler space telescope, told Discovery News."
Another theory proven wrong and improved (Score:5, Insightful)
A field in its infancy (Score:5, Insightful)
The number of solar systems we are familiar with is approximately 1. Therefore, it stands to reason that whatever theories we've come up with regarding planet formation are bound to have flaws in them.
This is a very interesting discovery, and it highlights just how little we know about the mechanics of the universe.
Re:Migration? (Score:5, Insightful)
There's a general axiom of science that the observer isn't specially priveleged. In other words, when it comes to astronomy, what we see looking out is similar to what everyone else would see. The trouble with that idea is that, because of statistical laws, it has to break down at some level - if you look for, say, 20 different things, each with a very high, say, 95% chance of occuring, there will probably be at least one that looks seriously atypical from your viewpoint (assuming those things can be treated independently, of course). Scientists tend to argue that on some scale the universe looks uniform to all observers, but that's not actually as useful a starting assumption as it sounds, because no one is sure just what that scale's boundrys are, the minimum sample needed is, or just what things are or aren't 'unifomitarian'.
For example, some 19th and early 20th century astronomers observing our own solar system, thought that Earth's having such a large moon was very unusual, and if there were extra-solar, earth-like worlds, they would usually have much smaller moons, if any. But until we can image objects the size of our moon across interstellar distances, for all we know, Venus and Mars are unusual in not having larger moons (or any moon at all in the case of Venus). The common idea, that Earth-Moon like 'double planets' are rare, is based on damned near no data.
For another, the Sun and the Moon have almost exactly the same apparent diameter as seen from Earth - surely that's just a statistically unusual coincidence, but technically, we don't really know but that it might be anomalously common, and in complete contrast to the random ratios we might expect, for the same situation to occur elsewhere.
Maybe it will turn out that gas giants in a system typically range from a largest one in the closer orbit, outward to a smallest gas giant in the largest of a series of orbits, (and our solar system mostly fits a standard rule) or maybe our solar system has it bass ackwards, or maybe gas giant size and orbit distribution is completely random.
One minor point: There are no stars 10 times older than our sun. At 4.75 billion years old, the sun is about 1/3 the age of the entire universe, so even the earliest stars formed are only about 2 1/2 times as old. So i'll predict that, if there's more 'odd configurations' in older star systems, it will have to manefest itself over a smaller range of ages.
Re:Migration? (Score:5, Insightful)
That assumption has not only messed up astronomy, but pretty much every field of applied science man is involved in. Look at all the resistance to accepting continental drift. Or evolution for that matter (nowadays at least the scientific community accepted it, but in the early days it was often a hard pill to swallow even for those who didn't feel the need to tag everything to a Bible passage - nowadays "everything is constantly changing and nothing is as it used to be" is a critical tenet of biology). It can hit multiple fields at once, like the assumption that any sizeable crater on Earth had to be volcanic, not from a large meteor, because that'd mean our planet and our solar system were still radically evolving. It gets some really smart people - for example, that assumption made it hard for Einstein to accept the Big Bang, that the universe was once some radically different place (in fact, no place whatsoever!) and is destined to become a radically different place still.
Re:A field in its infancy (Score:2, Insightful)
What if all of these conditions really are necessary - what if there isn't another more probable way to have intelligent life? (This presumes that we qualify as "intelligent" - most of the time I think we don't qualify as "wise". (as in "sapiens"))
"Space is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space, listen..."
That is from Douglas Adams, and it seems to apply very well here. People generally underestimate the enormousness of the universe, because it is so hard to comprehend its vastness. The universe is so mindbogglingly big, that even if all those conditions need to be met, not only will there be many places in the universe where this is the case, there will actually be places where the conditions are just a tiny bit better!
And don't talk to me about time! The universe is so mindbogglingly old, that even if all of those conditions need to be met, not only will it have happened many times over, but those same conditions will have arisen in many different ways, some of them in less time than it took for them to happen here.
Not only are there twin Earths out there, there are even well-tuned, supercharged Earths. It is our arrogance to think that our planet is the best way to evolve life. The fact that we haven't found any other life out there yet (or perhaps that we don't believe those who say that they have ;) doesn't show they aren't there, it shows that we aren't nearly as smart and advanced as we like to think we are.