Moons dance around Pluto
Moons dance around Pluto This illustration depicts Pluto and its five moons from a perspective looking away from the sun (AP photos)
Moons dance around Pluto
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There's a chaotic dance going on at the far end of our solar system. It involves Pluto and five of its closest friends, a study finds.

Hubble Space Telescope images of Pluto, its largest moon Charon and tinier moons Styx, Nix, Hydra and Kerberos show the odd rhythmic gyrations of the six distant objects. It's like a dance. But it is unlike anything in our solar system.

What makes it so odd is that there's a double set of dances going on. First, Pluto and Charon are locked together in their own waltz. It is "as if they are a dumbbell" with a rod connecting them. That is according to study author Mark Showalter of the SETI Institute in California. It's the solar system's only binary planet system, even though Charon isn't technically a planet, he said. Pluto, too, is no longer considered a full planet.

"It's pretty darn weird," Showalter said.

But Pluto and Charon aren't alone. And that's where it gets more complicated.

The four little moons circle the Pluto-Charon combo. They wobble a bit when they go closer to either Pluto or Charon. They are being pushed and pulled by the two bigger objects.

Those four moons orbit Pluto-Charon in a precise rhythmic way. But there is a twist. They also interact when they near each other. So it seems like they all dance to one overarching beat but not quite in the same way. They are just doing their own thing, said planetary scientist Heidi Hammel of the Association of Universities for Research in Astronomy.

"It's kind of like you'd see at a Grateful Dead concert," Hammel said. She wasn't part of the study. But she praised it as giving a glimpse of what might be happening in other distant star systems where there are two stars and planets that revolve around them. It is like the mythical Star Wars world of Tatooine.

With the tiny moons wobbling and flipping over in an unpredictable and chaotic way, if you lived on Nix or Hydra, the sun would come up in different parts of the sky. If at all on some days, Showalter said.

"It's a very strange world," he said. "You would literally not know if the sun is coming up tomorrow."

NASA's $700 million New Horizons spacecraft will arrive in the Pluto system in mid-July. It has been on a nine-year 3 billion mile flight. It began before Pluto was demoted to dwarf-planet status.

Critical thinking challenge: Why are the moons movements referred to as a dance?

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Assigned 68 times

  • Jorge-Par
    6/10/2015 - 08:15 a.m.

    I have never seen space but I bet it's very cool I wanted to be a asternot when I was I little kid but now I want to be in the army

  • Milo-Par
    6/10/2015 - 08:18 a.m.

    Pluto has five moons!!?? That's a lot of moons for a tiny planet! I wonder how the moons "dance"? They must be really small! Crazy!!!!

  • Estella-Par
    6/10/2015 - 08:19 a.m.

    I read this story. This story was bout Pluto and it's five moons. I thought about the 'Critical Thinking Challenge' and here is my answer: I think they call it 'dancing' because they bob and move because of Charon's and Pluto's gravity. Then the moons look like they're 'dancing'!

  • TR2001Blue
    6/10/2015 - 08:37 a.m.

    The moons move in a little pattern in which they look like they are dancing in their own way and it is a special way that they move or "dance". That is why the moon's movement is referred to a dance.

  • JJ01blue
    6/10/2015 - 08:42 a.m.

    Why are there six moon around a dwarf planet and is it possible for one of those moons to crash into them and mess up the chaotic dance

  • kevik-4
    6/10/2015 - 12:10 p.m.

    In this section it talks about how Pluto is a Darfur planet and it also talks about Pluto moons. The Hubble space telescope is there taking photos of Pluto and it moons and the other dwarf planets. It also talks about the New horizon spacecraft it is headed toward Pluto and the spacecraft started before Pluto was evidence considered a deaf planet. Pluto has six moons and they all rotate around Pluto. I think it is kind of cool that people were able to decide that Pluto was a Darfur planet. I hope that the Hubble telescope will take detailed more photos of Pluto.

    • cF00oKc
      6/12/2015 - 08:40 a.m.

      in did know that its cool moon goes around pluto the should put things on the moons that goes to pluto to learn more about pluto or those moons.

  • ce2001blue
    6/10/2015 - 01:09 p.m.

    The moons movements are referred to as a dance because they are synchronized. They are moving together as one and basically dancing.

  • Steve0620-yyca
    6/10/2015 - 08:38 p.m.

    It is interesting and strange to see Pluto and its moons acting like that. Pluto has five moons and the biggest is a moon called Charon. Pluto and Charon are moving as if they are tied to each other by a string. It is strange how the other four moons are doing their own action or move. It is also kind of like Pluto and Charon are pulling and pushing the other moons toward them and away from them. NASA spent so much money (seven hundred million dollars) to make a spacecraft which will help the people know more about space. The spacecraft will be studying about Pluto and its moons. The seven hundred million dollar spacecraft has been serving NASA for a long time. I began before Pluto was considered a dwarf-planet.

  • CameronK-3
    6/11/2015 - 01:27 a.m.

    Pluto is having quite a dance involving one of the fundamental forces in nature, gravity. Charon, Pluto's largest moon, is orbiting Pluto with its center of gravity just outside of Pluto. It's is complicated but this is called a binary planet system. It gets even more complicated when you add Pluto's other four moons. These moons orbit in a strange way because they are influenced by themselves and the Pluto-Charon system. The smaller moons wobble in their orbits. I found this article interesting because I've recently heard about Pluto and I wanted to see more.

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