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From meteorite samples to atmosphere simulations, this week has been a banner week
for finding out what space is made of!
And not to spoil it or anything, but it’s some pretty cool stuff.
First up: meteorites!
Last week at a meeting of the American Physical Society, a team of scientists announced that
they’d found the first confirmed superconductors in meteorites.
Besides being a first, their discovery could someday help us
make super-efficient technology here on Earth.
Normally, when electricity flows through a conductor, like a copper wire,
the conductor resists that flow, and some of the energy is lost to heat.
This means most machines that use conductors aren’t totally efficient.
Superconductors can get around this problem.
They’re materials with virtually no resistance to electrical flow,
although they have to be really cold to do it.
Like, anywhere from -140 to -270°C!
At these temperatures, the atoms’ electrons start pairing up, which allows them to flow
extra smoothly with basically no energy loss.
As a bonus, superconductors also have a property called the Meissner effect:
They repel weak magnetic fields around them.
This is one reason why, if you put a superconductor in a magnetic field, it’ll float!
Scientists are interested in these materials
because we could use them in all kinds of applications.
They’d be great for building machines that have very little energy loss.
Researchers are also on the hunt for ones that work at room temperature, since those
would be way easier to use than ones that have to be cold.
Right now, they can make some superconducting materials in the lab, but meteorites are a
great place to search for new ones, too.
These space rocks sometimes form under really extreme pressures and temperatures that can’t
be replicated in a lab, so they might have all kinds of weird, neat stuff in them!
People had been looking for superconductors in meteorites for a while, but no one had
found any yet, partly because the available techniques led to pretty imprecise measurements.
But this team picked them out.
And they did it by creating a new technique based on the Meissner effect.
It’s called magnetic field modulated microwave spectroscopy, or MFMMS.
It uses superconductors’ magnetic properties to locate them in impure samples.
In this new method, a couple of magnetic fields are applied to the meteorites.
And ultimately, these fields force any superconducting materials in the rocks
in and out of superconducting mode.
That creates a signal that the team can use to pinpoint the metals.
And it works really well!
These scientists were able to identify mixtures of indium and tin in the rocks, along with
indium-tin mixes that had something else in them, maybe lead.
All of these are confirmed superconductors, though they only work at about -270°C. So
they aren’t the room-temperature holy grail we’ve been looking for.
But these results are still important, because they show us that superconductors are probably
widespread in rocks throughout the universe!
They also show us how this new technique can be used to find all kinds of materials,
even ones we’ve never seen.
So let the discoveries commence.
Now, you can’t simulate how all meteorites form in a lab, but one thing you can simulate
are the atmospheres of other planets.
You just pump some gases into containers and see what happens!
It sounds pretty simple, but these experiments are especially important when it comes to
studying exoplanets, and figuring out which ones could support life.
Last week in the journal Nature Astronomy, a team of scientists based at
Johns Hopkins University published a paper about their new atmosphere simulations.
And they’re going to really help out our telescope game.
Specifically, this team wanted to see which kinds of atmospheres develop photochemical hazes.
These are those sort of smoky fogs created when sunlight reacts with chemicals in the air.
Hazes can affect a planet’s temperature
and how much ultraviolet radiation reaches its surface.
And these are both things that shape whether or not something could live there.
We’ve studied hazes in atmospheres like Earth’s and also Pluto’s, but we didn’t
know a lot about what they could look like in other solar systems.
That’s what this team wanted to find out.
They mixed up nine different possible atmospheres in the lab, varying concentrations of nitrogen,
water vapor, organic materials, and other good gassy stuff.
Then, they heated them up with plasma to simulate stellar radiation and drive the reactions.
They found that every single atmosphere they tested produced some haze,
but more importantly, they saw that water vapor can play a huge role in haze production.
We used to think that most of these fogs were made through interactions with hydrocarbons
and nitrogen, because that’s what we see around here.
But the two haziest atmospheres the researchers simulated
had high amounts of water and low amounts of nitrogen.
So it seems like nitrogen isn’t always that important
and that water vapor can be a good substitute.
Knowing all of this will be important when NASA launches the James Webb Space Telescope,
which should happen next year.
I can’t believe it’s finally happening!
Webb will study tons of faraway exoplanets and should give us great observations.
But hazes can sometimes make it hard for
telescopes to determine which kinds of gases are in a planet’s atmosphere.
So if we know right from the start what mixes tend to produce haze, we’ll be able to better
interpret and fill any holes in the data Webb provides.
These experiments are kind of like doing prep work before you walk into your lab class.
So thanks to these recent studies, we now know a lot more about meteorites and potentially
habitable exoplanets, but somehow, we still have a lot more to learn.
Maybe thankfully, there’s a long way to go, and a lot more science to tell you about.
It would be kind of a shame, yeah?
If we just were like ‘Uh, science is done!
Thanks for participating in Scishow, we’re done.
All the science got finished, see ya!’
But that’s not happening.
So thank you for watching this episode of SciShow Space,
brought to you by all of our patrons on Patreon!
We couldn’t keep talking about space news without you, so thanks for all that you do.
If you would like to learn how to support the show, you can go to patreon.com/scishow.
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