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  • Something is up with Uranus.

  • Well, that's kind of an understatement

  • The seventh planet from the Sun is a real oddball in our solar system, and yet we've

  • only explored it once, back in the 1980s.

  • Scientists recently gave data from that mission a closer lookand discovered the ice giant

  • was doing something unexpected.

  • It turns out Uranus is leaking gas.

  • Let's just address the elephant in the room: Uranus.

  • It's unfortunate that astronomer Johann Bode chose to name it after the Greek god

  • of the sky.

  • I know, all the other planets are named after Roman gods.

  • What was he thinking?

  • But if it were up to William Herschel, who discovered the planet in 1781, we'd be calling

  • it Georgium Sidus after King George III of England.

  • So, Uranus it is!

  • Since that's what I'll be calling it this whole episode, let's try and be mature about

  • it, shall we?

  • Anyway, Uranus is shooting gas off into space.

  • Tons of it.

  • Huge rips.

  • The data from our mission to Uranus, Voyager 2, show in 1986 it ejected a mass of electrically

  • excited gas roughly 30 times wider than Earth's diameter.

  • Where did this gas go?

  • Well because of the, ahem, solar wind,

  • the gas goes where the sun don't shine.

  • See this ejection of gas was what's known as a plasmoid.

  • They occur when ions from the atmosphere follow magnetic field lines.

  • These lines on the side facing the sun experience intense magnetic radiation from the solar

  • wind, sometimes enough to break them.

  • The field lines can then whip around to the back of the planet and reconnect.

  • When that occurs, the ions in the pinched-off portion are sent hurtling into space.

  • Plasmoids aren't uncommon; in fact they've been spotted around several planets.

  • But we only just noticed this one from decades ago because of a few complicating factors.

  • First, like I said, there isn't a lot of data, just what we have from that Voyager

  • 2 flyby.

  • And second, Uranus is just weird.

  • It and Venus are the only two planets that spin on their axes from east to west, opposite

  • of the rest of the planets in the solar system.

  • However, unlike any other planet, Uranus is sideways.

  • Its equator is almost perpendicular to its plane of orbit, possibly from getting smacked

  • by an Earth-sized object.

  • Side note, pun intended: this gives Uranus some crazy seasons, with summer on one pole

  • consisting of about 21 straight years of daytime while the other pole experiences 21 years

  • of continuous dark winter.

  • On many planets that have them, magnetic fields more or less line up with their geographic

  • poles, which is why a compass works well enough on Earth.

  • But Uranus just can't stop being silly, and its magnetic axis is tilted at almost

  • 60 degrees from its axis of rotation.

  • And to make things just that much more complicated, it's also offset from the planet's center

  • by about a third of the planet's radius.

  • All this makes for a very odd and twisted magnetic field with some unusual properties,

  • like it opens and closes to the solar wind daily.

  • So finding this plasmoid hidden in Voyager 2's magnetometer data required examining

  • it at a higher resolution than ever before.

  • Even in such fine detail, the plasmoid showed up as just a 60-second blip, meaning it was

  • one of those silent-but-deadly ones.

  • (Well, I assume it'd be deadly if you tried to inhale what is probably mostly ionized

  • hydrogen, anyway.)

  • When you take a deep dive into Uranus, you discover it's such a strange and magical

  • place.

  • I didn't even talk about how it possibly rains diamonds far under its gassy surface.

  • It's kind of surprising it was calledthe most boring planetafter Voyager 2's

  • pictures were underwhelming.

  • The scientists who spotted this plasmoid were looking for a reason to send a probe back

  • to Uranus.

  • Hopefully this data and an upcoming convenient alignment of planets in the 2030s encourages

  • us to further plumb the depths of Uranus.

  • Another acceptable pronunciation of the planet's name is "yur-in-us."

  • Could I have called it that this whole episode?

  • Yes.

  • Did I?

  • No.

  • We may not be going back to Uranus anytime soon, but we're very interested in Jupiter.

  • Specifically some of its moons that may have the right conditions for life.

  • Check out Amanda's video on that here.

  • Make sure to subscribe to Seeker for even more planetary updates and as always,

  • thanks for watching. I'll see you next time.

Something is up with Uranus.


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なぜ天王星はプラズマの泡を撮影しているのか? (Why Is Uranus Shooting Plasma Bubbles?)

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    Summer に公開 2021 年 01 月 14 日