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Despite how we normally talk about it, space is anything but an empty vacuum:
The Sun is, for example, constantly shooting out
streams of charged particles and other radiation that interact with Earth.
It’s kinda like space weather, and just like regular weather, it gets a little dangerous.
Like, solar flares throw out huge amounts of high-energy radiation,
which can damage electronics and threaten astronauts in space.
So, being able to predict the next big flare is a huge goal for researchers.
And last month in the journal Science,
one team published a model that might actually be able to do it.
The exact process that causes solar flares is still a bit of a mystery,
which is why it’s been so hard to predict them.
But we know it has something to with the Sun’s magnetic field.
To be a little more specific, the lines of its magnetic field sometimes get all tangled up.
And to straighten themselves out, they break and reconnect.
This is officially called magnetic reconnection.
And according to this team of scientists in Japan,
a certain kind of magnetic reconnection might go on to produce a flare.
It requires two loops in the magnetic field
to be close enough and roughly aligned with one another.
If something comes along and disturbs them,
the loops can get tangled and reconnect to form a bigger loop shaped like the letter M.
Or what the authors call a double-arc instability.
As that loop grows upward, it triggers more magnetic reconnections below it.
Then, those field lines move upward, triggering another reconnection, and so on.
It’s a positive feedback loop that stores a bunch of energy.
And that energy eventually gets released as a solar flare.
Now, the key is, that instability only seems to form at boundaries where
the Sun’s magnetic field switches polarity, positive on one side, negative on the other.
In other words, what we might call the north pole swaps sides.
Also, the magnetic field above the area, in the Sun’s atmosphere,
has to be weak enough for this runaway feedback loop to happen.
So, the hypothesis is: If you monitor the instability of the magnetic field at these boundaries,
and if you monitor the strength of that instability compared to the magnetic field above it...
...you can predict when and where a solar flare will happen, and how strong it will be.
The team didn’t just leave it at that, though: They also built a model to run on a supercomputer.
Then, they tested it, looking at data collected by
NASA's Solar Dynamics Observatory between 2006 and 2019.
The data covered roughly 200 active regions of the Sun’s surface.
And seven of them produced nine powerful flares.
For the most part, the model was able to predict that
these flares would happen with up to about 20 hours of warning.
That would be enough time for astronauts and electric companies to start preparing.
Of course... it also predicted three flares that never happened, and it missed two that did.
But in its defense, those two were not normal flares:
They didn’t come with the massive plasma ejection that usually comes with solar flares.
They may have also originated far above the Sun’s surface,
and the team admitted that their model doesn’t work as well up there.
Still, some of the previous methods we’ve used to predict solar flares
have done worse than a computer making random guesses.
So, if testing confirms that this new model at least mostly works,
it’ll be our first real, predictive tool.
Our next story takes us out of the solar system and into the center of the Milky Way.
Last week in the journal Nature, astronomers reported that
our galaxy is farting blobs of cold gas, and they haven’t the foggiest idea why.
Now, these weren’t the exact words used in the paper, I’m summarizing it.
A decade ago, astronomers found two huge bubbles
coming from the center of the galaxy, filled with plasma, hot gas, and gamma radiation.
They’re called Fermi Bubbles, and they stretch roughly
30,000 light-years above and below the Milky Way’s disk.
But it’s not clear what’s making them.
Maybe it’s nearby star formation, or maybe it’s the galaxy’s supermassive black hole.
And now, there’s even more of a mystery.
Using the Atacama Pathfinder Experiment based in Chile,
a team was studying two hydrogen gas clouds within the Fermi Bubbles.
And they spotted something weird: cold blobs of carbon monoxide gas. And big ones.
They measured a few light-years across and weighed in at around 380 Suns each, at minimum.
And it’s a complete mystery how they got there.
To fling such dense, cold gas out of the center of the galaxy,
the supermassive black hole would need to be radiating a lot more energy than it is now.
Or the rate of star formation would need to be a lot higher to create enough of a stellar wind.
That’s the stream of particles that stars send out as space weather.
Still, one thing we do know is that some of this gas is escaping the galaxy.
The team estimated that the amount comes out to
around a tenth the mass of our Sun each year.
That might not sound like much,
but it’s enough to significantly affect how many stars can form.
So, learning more about these cosmic blobs
could help us understand more about how the center of our galaxy will change.
Also, although we don’t know why this is happening,
scientists have seen something similar in distant, more massive galaxies.
And since we now have a version of this on our cosmic doorstep,
it’ll be easier to study and learn more about how those galaxies change over time, too.
So, not bad for some cosmic fart bubbles.
Thanks for watching this episode of SciShow Space News!
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