This Hot Jupiter Is Leaking Metal! | SciShow News

In the world of exoplanets, the easiest to
find are the Hot Jupiters
— large gas giants that orbit super close
to their host stars.
For years, those were the only planets beyond
our solar system we could detect.
Even though our technology can now hunt for
Earth-like worlds, studying Hot Jupiters is
important for learning about how planetary
systems evolve.
So astronomers are still hard at work learning
all they can about these first-gen exoworlds.
And this month in the Astronomical Journal,
they’ve announced that the Hubble Space
has found the first planet with metal gas
its atmosphere — which offers us further
into the planetary life cycle.
The planet in question is known as WASP-121b,
whose discovery was announced back in 2016.
It’s about 20% more massive than Jupiter,
but has nearly twice the diameter, so it’s…
It’s located about 900 light-years away
from us
orbiting an F-type star, one slightly more
hotter, and brighter than our own Sun.
There’s been previous research studying
in 121b’s atmosphere, but for this study,
astronomers were looking for metals.
They did this by looking at the wavelengths
of light
coming from the star that passed through the
atmosphere during a transit — those are the
times when
the planet passed in front of the star relative
to us.
Whatever light’s missing clues us into the
that are in the atmosphere.
The team detected ions of magnesium and iron.
Finding metals in Hot Jupiter atmospheres
isn’t new,
but they usually hang out in the lower atmosphere
as clouds.
For WASP-121b, these metals were not just
in the atmosphere — they were also found
so far away
from the planet they’re no longer bound
to it by gravity.
The planet is shedding metal!
The reason for this is because WASP-121b is
so stinkin’ hot.
Its upper atmosphere clocks in at around 2500
degrees Celsius,
10x hotter than any other known exoplanet.
And it gets to that toasty temperature because
it’s less than
four million kilometers away from its star,
The planet’s year is only 1.3 Earth days
WASP-121a emits more ultraviolet light than
our Sun,
so it’s actually heating up the planet
more than our Sun would.
The magnesium and iron also help heat the
because they absorb a lot of UV light.
This heating puffs up the atmosphere,
giving the stuff further away from the core
an easier job
of floating off into space.
Basically, the hydrogen and helium in the
upper atmosphere
are flying off the planet, taking the magnesium
and iron with them.
This is thought to be a standard part of
Hot Jupiter evolution — they form further
out in the solar system,
but migrate inward and lose their outer atmosphere
as they get hotter.
So WASP-121b is a great piece of evidence
in astronomers’ hunt to understand
the formation of gas giants.
But looking at things on an even bigger scale,
a new 3D map of the Milky Way was published
last week
in the journal Science, which revealed that
our galaxy is a bit twisted.
It’s hard to figure out how far away stuff
is in space.
But one tried and true method since the early
involves a class of young, bright stars called
Those are stars that are varying in brightness over
but their variation is incredibly regular.
In 1912, astronomer Henrietta Swan Leavitt
that the brightness of a Cepheid was directly
to the period of its variation.
The brighter the star, the longer it took
to vary in brightness.
So by measuring a Cepheid’s period, you
know how bright
it’s supposed to be.
By comparing that against how bright it looks
in the night sky, you can determine how far
away it is.
There’s a bit more to it, but that’s the
So a team of astronomers based at the
University of Warsaw put together data from
2,431 Cepheids located within our galaxy,
collected by a variety of survey missions,
and determined their location within the Milky
relative to the Sun.
And when they plotted these stars in a three-dimensional
they discovered that the so-called disk of
our galaxy is not flat.
It’s warped, starting at a distance of around
8 kiloparsecs from the galactic center.
The warping becomes steeper at about
10 kiloparsecs out, up the edge of the galaxy
at 20.
And our side of the Milky Way is warping in
opposite direction as what’s happening on
opposite end of the galaxy.
In other words, if you look at it edge on,
our disk is vaguely s-shaped.
Near the edges, our disk also flares out.
While nearer the center it’s only about
500 light-years thick,
out in the galactic boonies stars can be up
5000 light-years away from the galactic plane.
This may be due to gravitational interaction
with nearby galaxies, or maybe even dark matter.
We don’t know, yet.
And this isn’t the only evidence that our
galaxy is twisted.
This new finding seems to match up with other
including a paper published earlier this year.
But having a funky shape doesn’t make us
The are other spiral galaxies out there with
warped disks
– maybe as many as half of them.
Even our next door neighbor, Andromeda,
isn’t perfectly flat.
Since the Cepheids in this study weren’t
distributed evenly
through the Milky Way, our new 3D map of home
not be 100% accurate.
But it’s a starting point, and more data
should be able to refine it.
And yes, that may make all of that art out
depicting our galaxy a little bit out of date,
but it’s worth it to actually know more
about our cosmic neighborhood.
Thanks for watching this episode of SciShow
Space News.
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and will ship in September, at which point,
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And thanks!


  1. If this Hot Jupiter is outgassing metal then its' core must be so hot that despite the stupendous interior pressures it's liquid and therefore convection currents are able to dredge up the core to its' surface.

  2. Should we still say "orbiting", or should we say "was orbiting" when it's 900 light-years away… It's not that much time, but we really don't what's going on just now!

  3. Dibs, I call dibsy's on mineral rights for WASP-121b- and it's orbital path
    heh, my descendants are gonna be crazy space rich

  4. Would be interesting to understand the future of that hot Jupiter in a couple billion years. It's loosing mass. What will be left when most of the upper atmosphere is stripped away.

  5. What if the black matter wasnt that but lots off different tidal pulls from large stars to small black holes we cant detect? What if everything is held together with the impending doom of slowly being eaten by smaller blackholes that want to be part of a super massive blackhole? Just a theory.

  6. There was already an article published last month showing the milky way disc is twisted with data from Gaia:

  7. Are you going to talk about Mauna Kea and the protests against the thirty meter telescope? How about that the other telescopes have been non-operational for 3 weeks?

  8. Huh. I thought Jupiter was about as big as gas giants could get, because any more massive & they hold onto their gas more tightly, making them smaller. I guess Jupiter isn't as close to that border as I was led to believe.

  9. finally people realized that the galaxy cant be "flat". one would assume quadrant of stars could be counted and compared, then using angle and distance plot objects location relative to you

  10. It's like a cosmic scale sputtering machine. Imagine the comets orbiting further out being repeatedly coated by layers of magnesium and iron as they orbit.

  11. Scientists know what's in the atmosphere of a planet 850 lightyears (eight quadrillion kms = 8'000'000'000'000'000 km) away… and Big Foot ppl can't get anything more than a dark blurry smudge of a photo of Saskquatch.

  12. Ever think how delicate we are. 100% of the universe will kill us. Literally the only place we can even live longer then 5 seconds is earth.

  13. I think the milky way is oscillating, very slowly and in an oscillation there is may be some flat shape at sometime. Any measurement of the frequency?

  14. Ten times hotter? You can't multiply temperatures in Celsius.
    2500 Celsius is 2773 Kelvin.
    That's 10 times 277 Kelvin, which is 4 Celsius.
    So you are saying that thus far, no known exoplanet had an atmosphere warmer than 4 degrees Celsius.

  15. I just thought of something. In movies ships are shown to meet each other in the same orientation but in reality wouldn't they be in completely different orientations considering there isn't a universal up or down

  16. "The hydrogen and helium in the upper atmosphere are flying off the planet, taking the magnesium and iron with them"
    OK: lightest elements are carried off due to "puffing up" of the atmosphere.
    But how do H and He manage to kidnap Mg and Fe? Text doesn't make sense to me.

  17. I wonder if it might be a by-product of galactic megers? I have no clue what I'm talking about, it was just an idea.

  18. Wake up people of America. I have given the message of what is to come. Pay attention and listen whether you want to hear it or not.

  19. Spaced… the Final Frontier… To boldly space out where no one has spaced out before.

    Except for all the aliens, of course.

  20. Me, reading an article
    Scientist: "our galaxy is actually not a flat disk, but more like a poached egg sliding on a spoon."

  21. Maybe our warped disk is an effect of the fusion of once individual galaxies. Since they clashed at an angle, after millions of years spinning together it more or less straighten it self on the rotation disk. Uff Milky Way's gonna be pissed that after almost getting it flat Andromeda's gonna crash with it and make a mess all over again.

  22. I'm glad he mentioned that magnesium and iron were the metals detected. Until he said that, I was confused by which definition of metals he was using. Astronomers have a weird definition of metals, that being anything heavier than helium. Virtually everyone else uses the periodic table. Since this was an astronomy story, I didn't know which way it was going to go.

  23. Ahem. Exo-planets are not planets. If you look, the definition is "orbits the sun". Exo-planets are planitary bodies or planetoids, but definitely NOT plantets. (Oh, it's definitely BS, but that's my point. Probably anything that has the word "planet" in the description should be a planet and we should separate planet types into rocky, gas, ice, and dwarf, and plop Mercury in that last category).

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