Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical...
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Transcript of Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical...
![Page 1: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/1.jpg)
Planetary Rings
![Page 2: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/2.jpg)
Rings are swarms of orbiting particles
• Orbits have to be very circular
• Elliptical orbits will result in collisions, destroying the ring
![Page 3: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/3.jpg)
Rings Have to be Very Flat
• Inclined orbits will result in collisions and destruction of the ring
![Page 4: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/4.jpg)
Rings have to be Equatorial• Tilted orbits precess; the plane of the orbit
rotates due to the planet’s equatorial bulge, other satellites, and the Sun’s gravity
![Page 5: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/5.jpg)
A tilted ring won’t stay flat very long
• Particle orbits will precess at different rates
• Collisions will soon destroy the ring
![Page 6: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/6.jpg)
Rings, Gaps, and Resonances• When two objects return to the same
relative positions regularly, they are said to be in resonance
• Some resonances are stable. Mercury’s 3:2 resonance between its rotation and its orbit is an example.
• Pluto’s period is 3/2 that of Neptune’s. This resonance keeps the two planets from ever colliding even though their orbits cross.
![Page 7: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/7.jpg)
Rings, Gaps, and Resonances
• Some resonances create gaps. There are no asteroids with one-half Jupiter’s period because repeated pulls by Jupiter eventually would change the asteroid’s orbit.
• Gaps in Saturn’s rings are due to resonances with Saturn’s satellites.
![Page 8: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/8.jpg)
Shepherd Moons
Shepherd Moons help maintain the sharp edges of rings
![Page 9: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/9.jpg)
A Shepherd Moon Outside a Ring Tends to Drag Stray
Particles Back, Causing Them to Fall Back Into the Ring
![Page 10: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/10.jpg)
Outer Shepherd Moon
![Page 11: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/11.jpg)
![Page 12: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/12.jpg)
![Page 13: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/13.jpg)
![Page 14: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/14.jpg)
![Page 15: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/15.jpg)
![Page 16: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/16.jpg)
A Shepherd Moon Inside a Ring Tends to Speed Stray Particles Up, Causing Them to Rise Back Into
the Ring
![Page 17: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/17.jpg)
Inner Shepherd Moon
![Page 18: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/18.jpg)
![Page 19: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/19.jpg)
![Page 20: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/20.jpg)
![Page 21: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/21.jpg)
![Page 22: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/22.jpg)
![Page 23: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/23.jpg)
Rings Are Probably Short-Lived
• Gravity of the Sun and planet’s satellites constantly disturbs orbits of particles
• Collisions probably happen frequently
• Particles should drift out of the ring
• Rings around outer planets have probably come and gone repeatedly during history of Solar System
![Page 24: Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.](https://reader030.fdocuments.in/reader030/viewer/2022013011/56649d225503460f949f8125/html5/thumbnails/24.jpg)