The Most Metal Planet Fragment Ever

The Most Metal Planet Fragment Ever

[ ♪ Intro ] When stars like the Sun reach the end of their
lives, they balloon into red giants and swallow up any planets in their way. In our solar system, that will be the end
of Mercury, Venus, and Earth. They then shrink to a dying remnant called
a white dwarf, which is sometimes surrounded by a disk of,
like, ex-planetary dust. But in an extrasolar system
410 light-years away, scientists discovered a shard of a planet that survived the death of its star, according to a study published
last week in the journal Science. They discovered the object in orbit around
a white dwarf. In the star’s spectrum, they saw a repeated
pattern of light dimming and brightening. This told astronomers that something was moving
through the star’s disk of dust and creating a cloud of gas. That gas emitted a little extra light that
was noticeable each time it went around the star. And whatever was causing it seemed to be somewhere between a few kilometers and a few hundred kilometers wide. This makes it only the second solid body ever
discovered around a white dwarf. Now, the object’s circumstances are pretty
grim. Not only is it a lone survivor circling a
dead star, but it’s sitting in a disk of debris made of the remains of destroyed planets. But the fact that it exists at all is pretty
incredible. It’s way closer than astronomers expected
to find any planetary survivors. It’s so close, it’s actually thought to
be orbiting within the star’s original radius. Meaning, if you replaced the white dwarf with
our Sun, it would be orbiting inside of the Sun. Yeah.
So this thing orbits very quickly. Fast enough that it rings in a new year every
two hours. At this distance, the star’s gravity is
so intense, most planets or asteroids would be ripped apart. But somehow this fragment has held up. Scientists suspect that it’s because it’s
made mostly of heavy metals like iron and nickel. And such a strong chunk of metal could have
survived the destruction of its planetary system, the researchers say. “Metal” is also the word I would use to
describe this planetary fragment’s, like, whole thing. The researchers’ best guess is that it’s
the metal core of a larger planet that used to orbit farther out, before the death of
its star caused all the planetary mayhem. And this fragment of a past planet can tellus more about what kinds of planets make up extrasolar systems. It can also offer us a hint at our solar system’s
future, and what traces might remain after our Sun dies. This planetary remnant isn’t the only interesting thing that has turned up recently in a disk of debris, either. In a preprint of a paper accepted for publication
in the journal Astronomy & Astrophysics, researchers announced that they’d discovered a comet
around the young star Beta Pictoris. That’s right, an exocomet. They found it in data from TESS, the exoplanet-hunting satellite that launched last year
as a successor to Kepler. And the fact it’s already got an exocomet
discovery under its belt is pretty promising. There’s been pretty strong evidence for
a while that exocomets are out there. Astronomers studying the emission spectra of stars saw that sometimes certain wavelengths of light were getting absorbed for a few hours
at a time. So they could infer that something comet-sized
was passing in front of these stars. One 2014 study even suggested that there were
thousands of exocomets around Beta Pictoris alone. But it was hard to be certain about any of
this. The best evidence would be in the form of
a light curve: a subtle dip in brightness as one of these comets passed in front of its star. It wouldn’t look like the dip that comes
from a planet. Planets are basically symmetrical, so the
light dims as the planet passes in front and then brightens when it leaves. But comets have tails. So the first half of an exocomet’s light
curve should look like a planet’s, a sharp drop in brightness. But then the drop should reverse more gradually,
as light starts to peek through the tail. Astronomers predicted 20 years ago that a
comet would have this kind of light curve, but our observations are just starting to
catch up. In its 9 years of operation, the Kepler telescope
found three potential instances of exocomets. But Kepler paid more attention to older stars,
which we think have fewer comets, as the chaos of planetary formation
calms down a bit. TESS looks at all kinds of stars, including
young ones, which are still surrounded with some building blocks that formed planetary systems. And the fact that it’s already found one
exocomet gives us a lot of reasons to get excited about the science that’s ahead. Now that they know what
TESS is capable of, scientists will be on the lookout
for more signals like this. With more data, they can start to see what
kinds of stars typically have lots of comets, or don’t. And that can tell us about the role comets
play in the formation of planetary systems, and how common they actually are. So, whether it’s in the debris surrounding
a young star or the rubble swirling around a dead one, there’s a lot of galactic archaeology
to do in the years ahead. Thanks for watching this episode of SciShow
Space News, which is brought to you
with the help of our patrons on Patreon. If you like what we do here and want to help
us out, check out
to learn how. [ ♪ Outro ]

61 thoughts on “The Most Metal Planet Fragment Ever

  1. So it's either a planetary core or it's a planet in the proces of being formed out of recycled material from ancient planets ground up in the systems earlier history. Hm. I bet it's an alien installation.

  2. If a comet tail were interacting with the light from a star, I think it would not be doing so quite as the animation showed. During the time the comet body was still obscuring light, adding tail to the occultation should further DIM the light, with it beginning to brighten with a bump when the body passes, returning to normal gradually as the tail moves clear.

  3. Stands to reason that once a planet like Earth has been enveloped by an expanding dying star, that its iron-core is most likely to survive & remain in orbit!

  4. Being curious about this I tried asking Google if a planet could still orbit a star while inside of it and Google said Yes that in fact a star can orbit a planet. So I rewrote my question to can a planet survive inside a star and Google gave me a post asking if life can survive on a planet orbiting a neutron star.

  5. I find it mindblowing that the Earths iron core could still possibly survive as a heavy metal planet after the sun dies. Like that's just crazy cool. Go iron!

  6. If we are looking at a star and a comet passes between it and us wouldn't the tail be pushed towards us also by the solar wind?

  7. Wait a sec- comet tails come from gas / particles ejected from solar energy, which means the tail would be coming straight on if we are observing the star. So if the comet is passing in front of the star I would think this would have a W shaped dimming curve where we see both the tail and the comet until dead center, where we would see only the comet, and then we would observe the opposite as the comet transitions from dead center toward the opposite edge.

  8. Scishow you need to do an episode about space travel!!

    I had no idea we have to orbit planets to travel through space. I thought you could just get in a space ship and fly in whatever direction you want once you escape earths gravity.

    I knew about orbiting but I didnt realize it is essential to space flight. I am 27 years old guys. I know there are plenty of people like me. Please.

  9. Wait… isn’t the tail of a comet suppose to always be opposite to the star? (since it’s the solar wind creating it) … and if so, when moving in front of the star, at most you’d see a more diffuse shadow around it, but that would not affect the slope of the star’s brightness… it should still be the same “moving in” and “moving out”… right?

  10. Actually your depiction of a comet's tail light curve is wrong. The comet's tail point away from the star. As it begins its Transit they will be pointed in One Direction as it reaches the midpoint of the transit going to look more like a planet it'll be more around the tail pointing at The Observer where is it finishes the transit how to get a wider section of the tail again

  11. Woah, so if it was sensitive enough to detect something as small as a comet, do you think it could potentially detect extraterrestrial spacecraft?

  12. But shouldn't a comets tail be pointed straight away from the star and right at us? How would you see the tail as a dip? It would have to be very small effect at best I figure.

  13. Earth 🌎 sun 🌞 is carbon. Orange. Also didn't forget, you can die at anytime. Make sure you add that to every video. Chaos theory is bogus. Tinny human

  14. Did anyone else see the words on the preview and immediately started humming TMNT theme?

  15. Screw the earth going down with the solar system im all for the Gunbuster 2 stratgy of turning Earth itself into a space ship although how they did it in that anime was a bit rediculous in the form of two giant rocket engines straped to the earth along with a warp drive XD I mean give the planet some extra protection guys! XD Granted only way I'd be able to live long enough to see such a rediclous project would be if I turned myself into a machine and we don't have the tech for that yet although once we do I'm going full Cylon baby! Aka mind in a computer with multiple backup bodies to interact with the universe with…… I'm a weirdo aren't I -_-

  16. Cybertron Planet! 
    The homeworld of Transformers, I insist we attack it before megatron call his army to destroy Earth!

  17. …have they examined Kepler and Tess datas for shepherded asteroids at Lagrange points L4/L5, ±60° ahead/behind the giant gas exoplanets…

  18. We need to focus on robotics. No one needs to go to Mars or anywhere else just yet. In 50 years or less robotics could conceivably be the answer to capturing and harvesting objects like this and even Terra forming or creating habitats, without risking human life or maintaining the systems necessary to support humans. I am not saying "don't ever go", I am just saying the major brunt of the expense of having to create the systems to support human life could be drastically reduced.

  19. I get "Until we see it attitude." Any thing we see in our solar system is out their multiple of times over.

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