Kepler-36's 'Odd Couple' Defy Planet Formation Theories

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."

Comments

Another theory proven wrong and improved

[Quakeulf]

I love it when things like these happen. :3

A field in its infancy

[wcrowe]

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:A field in its infancy

[nedlohs]

Big planets near the star are the easiest to detect.

Near the star means short orbital period and so the thing we are observing is happening more often (planet moving between us and the star, the star moving due to the gravity of the planet, phases of the planet changing the observed brightness of the star, etc). Bigger means the effect itself is larger.

If you are observing the planet directly, then bigger means easier to see. And closer to the start means brighter (though also more drowned our by the star itself) and thus also easier to see.

Re:A field in its infancy

[dpilot]

I remember hearing years back that we were trying to generate models that would accrete solar systems out of dust clouds - "from first principles". At the time I read about it, none of those models would generate a solar system like ours.

Many have suggested that our oversized moon (oversized relative to Earth) is responsible for higher life, intelligent life, technological life, etc. The Earth-moon system also seems to have required a "just-right" collision between two bodies of just-right size at the just-right aiming, angle, and velocity.

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"))

What if in the "meaningful" universe, by some definition of meaningful, say the range of a Star Trek warp drive in a human lifetime, we really are alone?

At the very least, it makes laying waste to a functioning biosphere an even bigger crime.
One could also go nuts with religious implications.

I expect the reality of exoplanets to often be

[Rei]

weirder and more fascinating than even the most far-out science-fiction authors have envisioned.

Try to picture the implications, for example, of a tidally-locked hot super-earth. You can readily have a habitable-temperature cold side while the other side is hot enough to boil the surface off to plasma. What happens on such a planet? Obviously it would take detailed physics simulations to find out, but I would expect things like tremendous winds transporting matter in the upper atmosphere from the hot side to the cool side, where it'd condense and rain out. Condensation at the surface would be like chemical vapor deposition, glazing the surfaces in metals or crystals (depending largely on the oxygen availability). Condensation in the atmosphere would lead to rain of solid particles - depending on various factors affecting the formation, it could be anything from sand to beads of glass to gemstones. Will all the liberated oxygen from the hot side (oxygen makes up a large portion of planetary crusts) rain back out or could there literally be a substantial oxygen-based atmosphere on the cool side? And hey, you've got a large mass of conductive material moving plasma and metallic gasses overhead - sounds like a recipe for uneven, irregular magnetic field generation and lots of "weird" stuff like localized field pinching, flares, and other phenomena that you normally only get in stars. Perhaps even localized bouts of fusion at the pinches. Just from the rapid and extreme differentiation in the atmosphere as solid matter precipitates, combined with the high conductivity, you should get crazy lightning. And of course losing your crust to boil-off has to have some huge effects on tectonics.

Such a shame that it's so hard to get probes to these alien worlds; I'm sure some of them would be truly incredible to see. Of course, we hardly even know what's in our own solar system (for example, the subsurface oceans of several large moons), so I guess better to start there first. Even our own solar system probably has some really weird stuff that we've never imaged before, like the hypothesized metallic frosts on Venus.

Re:I expect the reality of exoplanets to often be

[oodaloop]

Try to picture the implications, for example, of a tidally-locked hot super-earth. You can readily have a habitable-temperature cold side while the other side is hot enough to boil the surface off to plasma.

It was a dark and stormy night. The lead sulfide rain fell in torrents — except at occasional intervals, when it was checked by a violent gust of ammonia wind which swept up the alien canals. In other words, a typical day on the dark side of Omicron 1.

Re:I expect the reality of exoplanets to often be

[oodaloop]

Are you kidding me? This is some of my best alien noir, or xenoir as I like to call it. Things really start to pick up in chapter two, where our hero is confronted by time-travelling ninja robots. But don't worry, he gets the hive queen in the end.

Re:I expect the reality of exoplanets to often be

[Jesus_666]

It was a dark and stormy night. The lead sulfide rain fell in torrents — except at occasional intervals, when it was checked by a violent gust of ammonia wind which swept up the alien canals. In other words, a typical day on the dark side of Omicron 1.

It was a dark and stormy night; the lead sulfide rain fell in torrents — except at occasional intervals, when it was checked by a violent gust of ammonia wind which swept up the crystaline streets (for it is on Omicron 1 that our scene lies), rattling along the gemstone-encrusted housetops, and fiercely agitating the scanty flame of the spontaneous bouts of atmospheric fusion that struggled against the darkness, when Edward George Bulwer-Lytton decided that science fiction really wasn't his genre.

Re:Migration?

[Artifakt]

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?

[Rei]

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.