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."

Re:Life adapts

[delinear]

I guess the tide serves a dual purpose, rising and falling tides will expose sea-dwelling life forms to the air, eventually a variant life form will evolve that can survive in both states, and that leads eventually to land dwelling organisms. On a world with no tide there'd be little opportunity for life forms to be stranded out of water in sufficient quantities for that mutation to take hold, or at least not in anywhere near the same timeframe.

Re:"Weird"?

[PineHall]

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

Re:Is it a surprise...

[camperdave]

Yes, who says life on other planets has to be similar to what we see on Earth?

Basic chemistry. You need to have chemical bonds which are stable, but not so strong that it takes vast quantities of energy to reform molecules. Carbon compounds and water soluble chemicals are where it's at, baby.

Re:Save the aliens!

[mr_gorkajuice]

Not sure the word 'fact' belongs in that sentence with the rest of the wild speculation.

It's a fact that it may be the deciding factor.

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.

Re:"Weird"?

[Mindcontrolled]

You need a working biochemistry before you can evolve anything. You are at best proposing a mechanism how life could move into a more extreme environment - and then there are still limitations. Thermodynamics is one unforgiving bitch.... There still has to be a somewhat stable environment to kickstart the process. And yes, you are of course right that this could be a local zone of beneficial conditions. That still lowers the probability of the process, though - and I have the suspicion that this probability is low enough even in a large scale decent environment.

Re:"Weird"?

[jd]

Absolutely true. When the Square Kilometer Array (eventually) comes online, it will be possible to directly observe any exoplanet Earth-size or larger at a distance of 1 AU or greater from its sun at a distance of 100 LY from Earth, provided it is not perfectly reflective or perfectly dark within the range of frequencies being looked at. (If there's even one absorption line, the planet will be visible.) With the current design, at the limits given above, the head of the SETI Institute has stated that such a planet would resolve to one pixel. (That particular talk was fascinating, BTW.)

However, consider that most radio telescope arrays have nothing like that collecting area, nor do they have anything like the effective dish radius. Most radio telescope arrays simply can't directly observe exoplanets at any significant distance. This is why indirect observation and indirect measurements remain the norm.

Re:Um yeah.

[confused one]

No, it's not safe to assume that all stars have planets around them... Many stars are binaries and closely orbiting binary stars might tend to toss any planets out of the system. Having said that, our closest neighbor (a trinary system of Proxima, Alpha Centauri A and Alpha Centauri B) is calculated to have somewhat stable orbital zones.

The likelyhood is that there will be something orbiting every star, because, as you say, it's all formed out of condensed clouds of stuff. Knowing they're probably there... and actually seeing them. Worlds of difference.