Giant Lasers Simulate Exoplanet Cores, Prove They're More Likely to Have Life

Slashdot reader vikingo9 writes, "By smashing a piece of iron to insanely high pressures, using a laser the size of a football stadium, a team of scientists led by Lawrence Livermore National Laboratory have discovered that exoplanets 4-6 times larger than Earth have an increase chance of harboring biological life."

The thinking goes that a molten core "is probably required for life to develop on a planet," Popular Science points out — and this experiment suggests that molten cores of larger rocky exoplanets "should stay hot longer than those within small worlds." "We're finding so many planets, and [one of] the big questions people have are: are these planets potentially habitable?" says Rick Kraus, a physicist at Lawrence Livermore National Laboratory who led the study... Kraus and his team wanted to find other ways to discern whether a planet is habitable. They explored a planet's ability to form a magnetosphere — a magnetic field that protects it from solar radiation, like the one around Earth does for us — as a window into habitability, Kraus says. Life as we know it wouldn't be possible without the Earth's magnetic field.

Magnetic fields are a result of molten planetary cores. Earth has a core composed mostly of iron, split into a solid inner core and a liquid outer core. Earth's magnetic field is caused by the convection of the liquid iron, meaning how it swirls: The cooler, denser liquid areas sink to the bottom, while the hotter ones rise like wax in a lava lamp. Studying an exoplanet's core in a laboratory is difficult because there are few ways to recreate such intense pressures and temperatures.

This is the first experiment to use iron under pressures that exceed those in Earth's core, Kraus says...

The team estimates that it will take a total of 6 billion years for Earth's core to solidify, whereas cores in large exoplanets of similar composition to Earth should take up to 30 percent longer.
Of course, the article ends with a few caveats: One issue with extrapolating these results to exoplanets is that those super-Earths can contain elements other than iron in their core, which would change their melting temperature by an unknown amount, Driscoll says. It will also be hard to predict how exoplanets cool because the mantle, the layer of hot rock surrounding the core, plays a huge role in how quickly the core can cool. And those exoplanet mantles could be made of "pretty much anything," he says.

Re:

[sirfer_99]

Maybe we get to have giant sharks too?

Giant Lasers simulating planet cores

[htwf_and_ip]

It was a cool video, but the title leads me to think: Do you want Death Stars? Because that's how you get Death Stars. Before you reply, it's just a joke. Please breathe.

Nice experiment

[gweihir]

But the "conclusions" look very much like wishful thinking to me and not scientific at all. Science works, but scientists do not always.

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[fermion]

Especially since we know pretty definitively at least one earth sized planet has life there is no reason that a larger planet could have life as well, but that is open for debate.

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[gweihir]

Well, the problem is that we have one sample and no clue at all how that sample came into existence.

There are nice theories, but they span from Panspermia (i.e. lots and lots pf planets with life) to the Anthropic Principle (i.e. we are alone and most Universes will not have life at all).

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[RockDoctor]

Panspermia - otherwise known as "throwing the dice where the mark can't see them". Whereas appealing to the Anthropic Principle is just a way seeming to dodge the question. It doesn't actually dodge the question - if you're in a universe capable of life originating, there's no reason it can't originate in 1001 places, not just 1 - which defeats the god-squad's objective.

Headline

[PuddleBoy]

Can't we tame down the headlines a little? Giant lasers hitting iron "prove" that some planets are more likely to harbor life?

I suppose they used the word "likely", so that gives them an out.

How about "Simulating large exoplanet cores with lasers leads scientists to speculate on greater probability of extraterrestrial life" ?

Stretching the headline past the breaking point

[Dorianny]

The articles headline "Long-lasting radiation shields may make super-Earths friendly for life"

Slashdot's "Giant Lasers Simulate Exoplanet Cores, Prove They're More Likely to Have Life"

Who's paying for this shit?

[AndyKron]

It took a ginormous laser to prove big planets cool more slowly than smaller planets? Who's paying for this shit?

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[crunchygranola]

The U.S. Deparatment of Energy that fund the aforesaid giant laser to do nuclear weapons related research (i.e. support the "enduring stockpile"), also LLNL claimed that the laser would achieve break-even for laser fusion, which it didn't, hasn't, and likely won't.

(Yeah I know about the hugely hyped shot this past year that acheived the very first time fusion energy caused more fusion, which is not anywhere close to what "breakeven" or "ignition" meant or means. They devised a new lowest possible bar in o

At least they found something to do with NIF

[parker9]

Since fusion was a bust.

Poor aliens...

[K. S. Kyosuke]

Exoplanets 4-6 times larger than Earth have an increase chance of harboring biological life

Exoplanets 4-6 times larger than Earth also have near zero chance of harboring a spacefaring civilization. Gravity is a bitch.

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[DavenH]

It's always possible, in principle, to launch from any gravity. You have to solve the inequality:

vel_exhaust * ln (rocket_mass_with_fuel / rocket_mass_without_fuel) > (2GM/r)

So, with high planet mass (if it also is compact like a rocky planet), you need some combination of an extremely fast exhaust (i.e. efficient engine), huge amount of initial fuel, or very slight rocket mass when it excludes fuel.

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[DavenH]

*Missed a on the (2GM/r)

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[K. S. Kyosuke]

Laws of physics are the same of everyone. If *our* orbital velocity were 30 km/s, we wouldn't have even achieved orbit by now, and to achieve orbit in the first place, we would have needed something completely crazy like open-cycle nuclear engines -- assuming that those actually work in practice. So chances are that if we were in that situation, we'd be imprisoned on Earth entirely. Plus, efficient engines don't usually have the thrust necessary to bring you to orbit, even in 1 g -- not to mention several g

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[RockDoctor]

Which is not untrue, but is not the question that even the Slashdot editor considered.

For "life" to get started, this isn't a problem

[RockDoctor]

Explicitly they're talking about planets considerably larger (specifically, more massive, not just physically larger) than Earth. But most of the Earth's radiation shielding comes from the atmosphere, not the magnetic field. And it is pretty unlikely (not impossible, but unlikely) that a larger planet than Earth would have a thinner atmosphere than Earth. So ... magnetosphere is unlikely to be a deal-breaker for life to originate.

Celestial in every planet's core

[wolverine1999]

Well there's a celestial in every planet's core according to the movie Eternals...

Formation of planetary iron cores

[RockDoctor]

A recent paper on ArXiv addresses the question of how you for an inner solid iron core in the molten iron core of a planet - which is believed to be necessary to produce the turbulent flow necessary to produce a self-stimulating dynamo.

The problem is that the "iron catastrophe" involved in separating the iron of a protoplanet from the rock it is mixed with, and it then settling to the middle of the planet, releases quite a lot of energy. (Depending on the composition, possibly enough to melt essentially al