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Back in July 2016, NASA’s Juno spacecraft entered orbit around Jupiter.
New missions are always exciting,
but this one was especially cool because
Juno had a different orbit than previous missions to Jupiter.
The spacecraft is looping around the planet’s poles,
getting as close as 3500 kilometers above the cloud tops
which is really close when you consider how big Jupiter is.
The mission will keep going for at least another few months,
but scientists are already picking apart the data from those super close flybys.
They’re studying places we haven’t had access to to until now,
including Jupiter’s interior.
And a group of papers published this week in the journal Nature
are sharing some of those key findings.
As a gas giant, Jupiter is mostly made out of fluids.
It also rotates pretty quickly, experiencing only 10-hour days.
Because of all that,
astronomers expected Jupiter’s mass to be distributed pretty uniformly.
But that’s not the case.
These recent findings from Juno showed us
that its mass distribution actually varies depending on the latitude.
It’s caused by streams of fluid,
both in Jupiter’s atmosphere and in its interior,
up to 3000 kilometers below the cloud level.
We also learned that, below that depth, fluid just doesn’t flow the same way.
Instead, a mix of hydrogen and helium rotates together,
almost like a solid body.
Of course, because of all the clouds,
we can’t actually look into Jupiter’s interior.
That would just be too easy.
Instead, scientists used Juno to measure how Jupiter’s gravitational pull
changes as the spacecraft performs its flyby.
As Juno moves around Jupiter, it gets closer to different parts of the planet.
Those different parts have different amounts of mass,
which means gravity there will be a little stronger or weaker.
That will either cause Juno to speed up or slow down.
Then, scientists can then measure those changes in speed
to tell how Jupiter’s mass is distributed.
This new Juno data is two orders of magnitude more accurate
than previous scans, and it’ll help us better model what’s happening
in Jupiter and in other fluid giants.
And there were even more findings, too.
One additional paper reported on the discovery of multiple cyclones
in both the north and south polar regions.
Using the infrared JIRAM and optical JunoCam,
Juno snapped photos of 15 separate storms,
observing them over seven months.
There were eight storms rotating around one storm in the north,
and five rotating around a storm in the south.
They all range between 4000 and 7000 kilometers in diameter,
and both sets of storms are arranged like polygons, which is cool.
Of course, it’s still a mystery how they originally formed
and how they didn’t manage to merge together
over the months they were observed.
It just means that there are still a lot more questions
astronomers need answers to.
And thankfully, Juno is sure to provide many more answers.
In other planetary news,
astronomers published a paper in The Astronomical Journal
announcing that a faraway exoplanet
has way more water in its atmosphere than we thought.
To figure it out, they had to create the most complete atmospheric profile
that’s possible with current technology.
The planet is WASP-39b, which was discovered back in 2011.
It’s about 700 light-years from Earth and orbits a star
with a mass similar to the Sun’s, although it’s older and a bit cooler.
39b’s mass is similar to Saturn’s,
but that’s about the only thing they have in common.
The most obvious difference is this planet doesn’t have any rings.
But it’s also much puffier.
It’s actually one of the least dense planets ever discovered.
It’s so puffy because it orbits really closely to its star
In fact, it only takes 4 days to complete one orbit!
All that intense heat fluffs up a bunch of the planet’s matter.
39b is also tidally locked,
which means only one side of the planet ever faces its star.
But powerful winds help move the heat around, so it’s fairly evenly distributed.
The planet has a toasty equilibrium temperature of over 1100 Kelvin.
Because 39b doesn’t really have any obscuring clouds in its upper atmosphere,
the Hubble Space Telescope could capture a good breakdown
of the atmosphere’s composition.
It did that by looking at starlight.
Specifically, it looked at light from its host star
that traveled through the planet’s atmosphere on its way to Earth.
Different molecules absorb different wavelengths of light,
so by looking at the wavelengths of starlight that are missing in the data,
astronomers can tell what kind of gases this atmosphere has,
and in what abundance.
What Hubble found was a lot of water vapor.
Like, three times more than we find in Saturn’s atmosphere,
which was totally unexpected.
They figured they’d find some water, but nowhere near as much as they did.
This suggests 39b was pummeled by a lot of icy material when it was forming.
Still, based on what we know about planet formation,
that would’ve only been possible
if the planet formed much farther from its star than it is now.
And, like with any good paper, that only brings up more questions.
Welcome to science.
This study adds to the complex list of ways planets can develop,
and it suggests there are a lot of star systems with different stories than ours.
As we collect more data through research like this,
we’ll just keep learning more.
And don’t worry -- there’s more to learn about 39b, too.
When the James Webb Space Telescope finally launches
which will hopefully happen next year
it’ll be able to measure how much carbon 39b has in its atmosphere.
It’ll also be able to see which carbon-based molecules
that carbon is locked up in.
That’ll help astronomers pin down
where the exactly the planet should’ve formed relative to its star.
By better understanding how other star systems formed,
we’ll be able to answer questions about our own neighborhood, too.
In November, we launched SciShow Finds:
a corner of the internet where we’ve collected artifacts of the universe
that fill us with wonder.
We were thrilled that you all cared about these special things
as much as we did, so we’re doing it again.
If you’re a citizen scientist, I picked out this PocketLab,
which is exactly what it sounds like,
a lab for your pocket
that helps you collect data out in the world and draw your own conclusions.
If you get a PocketLab, please, please let us know
what observations you make with it.
We’d love to hear about your experiments.
And longtime SciShow videomaker, Sarah Meismer,
has made this beloved lapel pin.
Get it?
Bee-loved?
It’s a bee.
In a heart.
Don’t bees deserve some more love?
Just like last time, we have a limited number of these special finds,
so we’ll keep them up until we run out or find new special things
that foster our love for science.
So head to SciShowFinds.com to learn more
and know that when you buy something from SciShow Finds,
you’re supporting the people who make and find these cool things
and supporting SciShow!
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