Weird Exoplanet Orbits Could Screw Up Alien Life

astroengine writes "Life is good in the Solar System. We have Jupiter to thank for that. However, if the gas giant's orbit were a little more elliptical, there's every chance that Earth would become rather uncomfortable very quickly. Researchers looking at the zoo of exoplanets orbiting distant stars have simulated several scenarios of differing exoplanet orbits and find that many don't resemble our cozy Solar System. In fact, weird exoplanet orbits may be the deciding factor as to whether extraterrestrial life can form or not."

Comments

Save the aliens!

[Anonymous Coward]

Dear friends,

The aliens of our galaxy have had a hard life. Please send donations to the buy-a-Jupiter-for-the-aliens fund. Your help is greatly appreciated.

Re:Save the aliens!

[mcgrew]

Has anyone considered that to them, we are the aliens? The link is a story about how our own solar system is uninhabited, and why.

"Weird"?

[sznupi]

If anything, all of this could be mean that our system is quite weird; at least on average.

And probably still wouldn't be a problem for "life" in general, considering there are several places suspected of harboring life in our own system, all of them quite "hostile" at first sight.

Complex life is another thing, of course... (or - we're frakked, because the aliens will turn out to be total badasses; due to evolving in very harsh conditions ;p )

Re:"Weird"?

[mcvos]

For complex life to develop, you need conditions that do regularly provide evolutionary pressure, without completely wiping out all life.

Asteroid impacts are fine and even very useful for wiping out stagnant populations (like the dinosaurs) and giving room for new species to develop into, but they shouldn't be so big that they demolish the entire planet, or occur so often that no life is possible on the surface of the planet. Jupiter plays a huge role in that.

But there are also other factors. I'm pretty sure that our big moon and the tides it generates are a big factor in creating ever changing environments that provide a lot of opportunities and evolutionary pressure for populations, and that's all caused by a devastating Mars-sized impact. But another one like that would easily wipe out all life here.

Weather, seismic activity, it all plays a role. I definitely think our planet has a good chance of being reasonably unique.

Re:"Weird"?

[Wiarumas]

But perhaps a badass exoskeleton life form wouldn't be that smart. Think of the Alien movies... they were highly evolved, but not really intelligent. Probably because they became such efficient killers that they never had to outsmart other animals. Which, as a result, would mean that unless we had to conquer a planet, we would never encounter such beasts. And if we did, I would hope that science would have had made enough advances allow us to effectively kill them seeing that we were able to overcome intergalactic travel.

Re:"Weird"?

[camperdave]

Maybe they feel dizzy in stable orbits, like pirates in firm land.

Ah! That would explain why they drink copious amounts of rum; to keep the land "unsteady".

Re:"Weird"?

[Mindcontrolled]

True, but highly elliptical orbits pose not only the problem of harsh conditions, but of rapidly changing, oscillating conditions. This becomes a problem for the evolution of a biochemistry because every complex chemical system is only stable in a rather narrow interval. If the oscillation is large enough, there might just be no stable biochemistry possible.

Given that you need a reasonable amount of complexity to implement the basic necessities of life, in particular information storage, as well as a metabolism, I don't see much of an alternative to a carbon-based biochemistry. Carbon-based chemistry is the most versatile system, able to build a near infinite variations of molecules - this is a singular property among all the elements.

However, organic molecules tend to be not overly stable outside of a rather small temperature range. On the one hand, this is good for life, because it provides the necessary chemical reactivity and flexibility to make a living system possible. On the other hand, this severely limits possible habitats for extraterrestrial life. On the gripping hand, the conditions on Earth are not just favourable for any random biochemistry, they are favourable for the most complex class of chemical compounds possible. This does not exclude the possibility of other biochemistries adapted to other conditions, it does, however limit the set of possible conditions for life.

Re:"Weird"?

[PineHall]

This fits the Rare Earth hypothesis which argues that complex life is rare in the universe. So earth's situation is "weird" and unusual if the hypothesis is correct.

Re:"Weird"?

[corbettw]

I wonder if there's a way to handle creatures like that from far away? Like, in orbit. You know, just to be sure.

Re:"Weird"?

[wiredlogic]

If anything, all of this could be mean that our system is quite weird; at least on average.

Possibly, but not likely. Our current planet detection methods are skewed toward finding the oddballs with high mass and highly elliptical low orbital periods. They induce the most wobble and occlude the most light from their stars. As such, they are the easiest to find over short observation periods.

Weird Exoplanets

[Thanshin]

"Captain. The orbit in this exoplanet is a bit weird. Summer might get be a bit warm"

"Let's surf in the beach, warm? Or Today we all stay in the fridge, warm."

"Sir, it'll be Hold your rifle with extended arms so the metal drops don't make holes in your boots, warm."

Re:Life adapts

[Thanshin]

If you lived on tropical shore where the climate was practically unchanging from day to day throughout the year, it would probably be hard to imagine life could exist in Canada.

Have you been in Canada? It's pretty hard to imagine life can exist there, wherever you're from.

I'm pretty sure they all migrated to some warmer place as soon as I left the country, only to return and scare the next tourists with stories about actually living there.

Hmmm,

[Anon-Admin]

First, Although the smaller inner planets would be hard pressed for life the moons of the gas giants orbiting closer to the sun could harbor life. There are only 8 (Or 9) planets in our solar system but there are over 300 moons.

Add to this that scientists seem to expect that life will only evolve on rocky earth like planets so it seems like a small chance. I know that the earth is the only example of life bearing planet that we have but to expect all life in the universe to exist in the same way that we do is narrow sighted. It would not surprise me to find out that there are fish swimming in a methane ocean on a distant planet in temperatures that would kill us.

Some day I fully expect to hear "It's Life, but not as we know it" and it not be a star trek reference. Well, Ok, how about only 1/2 a star trek reference. ;)

Um yeah.

[DaveV1.0]

Of course, the fact that we are finding these weird systems may simply be because they are the easiest to detect and all the stars with planetary systems like ours are thought to not have planets because we can't detect the planets using current methods and data.

Remember, Jupiter orbits the sun once every 12 years. So, if we were trying to detect our own solar system at 10 light years, how long would it take to detect Jupiter's effect on Sol's position?

Re:Um yeah.

[confused one]

You've hit the nail on the head. We're seeing these systems because either the gas giant is so close to the star that it obviously occludes the light and affects the radial acceleration of the star, or because their orbit extends far enough out from the star that it intersects with and modifies the surrounding debris cloud (think Oort).

Kepler and COROT are starting to return results. They'll need a decade or two to identify Jupiters and Kepler will need 4 or 5 years to identify an Earth or Mars.

Re:Life adapts

[TheRaven64]

The problem is expecting life to continue to adapt if it lives on a tropical shore for millions of years, then the next year the sea freezes. A lot of factors have contributed to the evolution of life on Earth. Jupiter is large enough that it captures most large chunks of rock that could cause mass extinctions. A few have it Earth, but not nearly as many as without a large gas giant. If these happen too frequently, it's hard for the ecosystem to recover. We needed one thought to split off the moon. Without the tidal forces, the surface radioactivity would be much lower and mutation rates would be very low, meaning that evolutionary changes would take longer. Intelligent life might still have evolved, but it would have taken a lot longer.

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