I’m Hank Green; this is SciShow News, and I’m wondering: Do you enjoy the sun?
And the fact that it exists?
Me too!
Although I’m not always sure the feeling is mutual.
Last week on May 8th, for instance, a big solar flare lashed out from the sun, practically
punching us in the face.
A solar flare, an explosive release of magnetic energy on the surface of the sun.
The sun’s magnetic fields are complex, intertwining, and ever-changing.
And sometimes when those fields intersect, pressure builds and eventually releases jets
of electrons, ions, and atoms -- more energetic than millions of hundred-megaton bombs going
off at once.
Last week’s flare was considered only a moderate one, a so-called M-class flare.
It was only a tenth as powerful as what happened back in March.
That’s when we witnessed an X-class flare -- the most energetic kind -- and astronomers
said last week that it was the best-observed solar flare in history.
On March 29th, four different space telescopes and one ground-based observatory were all
trained on the sun when the flare happened, and together, they were able to monitor different
features, observing it in different wavelengths, to give us a fuller-than-ever picture of a
solar flare.
Thanks to some excellent planning, astronomers with The National Solar Observatory in California,
Japan's Hinode satellite, and a whole alphabet soup of NASA telescopes were able to coordinate
in advance to focus their instruments on the same, active region of the sun that was looking
like it was gonna blow.
They’re now studying that data to better understand exactly what catalyzes this release
of pressure, and hopefully predict when the next one will happen.
Radiation from a solar flare is absorbed in Earth's atmosphere, so it doesn’t harm us
directly.
But it can disturb things like GPS and communications signals, which circulate in the outer atmosphere,
not to mention astronauts in orbit.
So the better we understand solar flares, the better we can be at preparing for them.
And here’s another thing we can now visualize better than ever: The formation of the universe.
For the first time, we can test all of the theories we have about how the universe formed
and the laws that govern it, by plugging them into a new, Web-based virtual model of the
cosmos.
A model that YOU can play with yourself!
Last week a team of physicists led by the Harvard-Smithsonian Center for Astrophysics
released Illustris, a simulation so complex that it took the team five years to design,
and the calculations had to be run on the equivalent of 8,000 desktop computers for
three months.
More than just cool graphics and animations, Illustris is a working visualization of LOTS
of physical data, which allows us to see how they play out based on our current understanding
of the physical universe.
Because there’s a lot we don’t know about the universe, but there’s also a lot that
we think we DO know.
Like, we think it started with a Big Bang.
And fractions of a second after that, space itself expanded faster than the speed of light,
marbling spacetime with shock waves of gravity.
Dark matter began to clump where gravity was strongest, developing into a web-like pattern.
This is where Illustris begins, a mere 12 million years after the big bang.
From there it models the universe’s evolution -- pretty accurately -- to the present day.
You can watch visible matter collect into webs, stars form from clouds of hydrogen and
helium, and planets begin to form as well.
As time goes on, more than 41,000 galaxies form in familiar shapes--spiral galaxies like
our own, and elliptical ones.
All of this happens in Illustris, which represents a cube of space 350 million light-years wide--large
enough, astronomers think, to be representative of the known universe.
And it leaves us with a present-day cosmos remarkably similar to ours.
But only similar, not exactly the same, of course, and therein lies the beauty of the
simulation.
Certain details, like how galaxies merge, are occurring differently in Illustris than
they do in the observed universe.
Astronomers have yet to comb through the simulation thoroughly enough to pinpoint the reasons
for these discrepancies.
But when we do, these will let us refine our theories about the universe--places where
we can begin to look closer, and rethink what we think we know.
Thanks for watching this episode of SciShow Space News -- especially to our Subbable subscribers.
If you want to keep exploring the universe with us, go to Subbable.com/scishow to learn
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