New Model Helps Predict Earth-Sized Planets

look over yonder writes "A new computer model created by astronomers from the Smithsonian Center and Astrophysics and the University of Utah predicts that systems which harbour Earth-sized planets will have a fingerprint of a ring of dust orbiting the star. This model will make it much easier for astronomers to locate stars and predict the size of planets orbiting it by simply measuring how bright the star system is at infrared (IR) wavelengths of light. Stars with dusty disks are brighter in the IR than stars without disks. The more dust a star system holds, the brighter it is in the IR."

Comments

Absorption/re-emission?

[aurum42]

Unfortunately the article is a little light on details. Presumably the IR signature is due to absorption and re-emission by the dust cloud, but I'm curious as to how they distinguish between a "normal" dust cloud and one that's due to an Earth sized planet. Interesting.

Re:Absorption/re-emission?

[Anonymous Coward]

As I understood it from the article. The IR signature is due because in a planet forming protoring, small planets wip asteroids etc around in gravity slingshots, in the long term this means alot of those asteroids will smash together at very high speed, basically blowing each other up into lots of hot dust, and as such, lots of infrered radiation.
I figure the rate at which this dust is formed, correlates to the weight of the planets doing the slingshotting, thus getting you a specific IR signature.

Quickshot

Re:Absorption/re-emission?

[Tau Zero]

I'm curious as to how they distinguish between a "normal" dust cloud and one that's due to an Earth sized planet.

The article states "The size of the largest objects in the disk determines the dust production rate. The amount of dust peaks when 600-mile protoplanets have formed." The dust forms in roughly the same orbit as the planet, so presumably you could detect a protoplanet forming at an Earth-like distance by watching for dust at a temperature of ~250 K; if there was the amount of dust you'd expect from an 8000-mile planet (well down from the peak at the 600-mile planetoid size), you might well have something like the prototypical Earth in that orbit.

I'm not sure how useful this is going to be in locating habitable planets; getting to them long before the intense bombardment phase has stopped isn't going to make for good colonization prospects. On the other hand, as a way of calculating the prevalence of Earth-like planets this is a huge breakthrough.

Finding life?

[Via_Patrino]

"predicts (...) systems which harbour Earth-sized planets"

I don't think that's not the only way of finding life or an enviroment friendly to humans. Earth-sized moons of big planets can have a more friendly enviroment than earth-sized planets.

Re:Finding life?

[ajax0187]

I can see the purpose of this if it's just for finding planets for the sake of finding planets. But if we're using it to see where the next intelligent life comes from, aren't we going a bit extreme? There is usually a couple billion years between when a planet is still a protoplanet and when it can sustain life. Yes, there can be millions of years between when we actually see the light from the star and the star itself (interstellar travel at the speed of light and all), but what about the systems that are only a few thousand light-years away?

Big honkin' Van Allen belts

[Latent Heat]

Given the "hot Jupiters" found orbiting nearby stars, there is nothing to say that a gas giant as to be 5 AU out -- you could have one in Earth's orbit with habitable moons all around.

But Jupiter has a strong magnetic field and an intense set of radiation belts through which its moons orbit. It would be a reasonable assumption that a gas giant would have a strong magnetic field as it probably has a core of hydrogen in some kind of superfluid, conducting state (compressed liquid hydrogen, metallic hydrogen, and other hypothesized states).

Are any of Jupiter's moons colonizable from a radiation standpoint?