Planetary Ring Systems - University of Alabama

Planetary Ring Systems - University of Alabama

Planetary Ring Systems Rings:

A B C 4/4 Giant Worlds Have Rings

Jupiter: broad, dark, fine particles Saturn: broad, bright, complex, icy particles Uranus narrow, dark, fine particles

Neptune: uneven, fine particles All consist of independently orbiting small chunks of material within very thin layers. Saturns rings span 100,000 miles, are only

a few yards thick in places. Why rings? Tidal forces destroy a large solid moon insides a planets Roche

limit. Ring systems are always found inside the Roche limit (about 1.44 planet diameters above the surface). Collisions make rings the final configuration for swarms of Individual particles in orbit; they sap energy but not momentum.

Comet Shoemaker-Levy 9 following a 90-minute excursion within Jupiters Roche limit.

This is not a large gravitationallybound moon How do they stay there?

Random motions should make some particles leave the rings and limit their lifetime. External effects can help herd stragglers back. Main example: shepherd moons.

Pan and Prometheus shepherd Saturns outer thin F ring Internal structures Rings can be very thin. Radial structures can be produced

by gravitational influences (such as perturbations and tides from nearby moons). Example: Cassini division in Saturns rings. Weaker disturbances and wave patterns can divide a ring into myriads of ringlets.

Wave patterns in Saturns rings (unprocessed

Cassini data, July 2004) Arcs of enhanced

particle density in rings of Neptune (Liberte, Egalite, Fraternite; they were

found in 1989) Origins Some ring systems are intimately tied to small satellites

as sources of particles. But where did all that ice around Saturn come from? Puzzles

Radial spokes in Saturns rings How long have rings been there? Are they part of a perpetual juggling act?

Voyager 1 time-lapse movie (contrast enhanced) of ring spokes

Recently Viewed Presentations

  • Valgerður Andrésdóttir - visindafelag.is

    Valgerður Andrésdóttir - visindafelag.is

    Maedi-visna virus. CAEV. EIAV. FIV. BIV. Lentiveirur af ætt Retroveira (lentus=hægur) Mæði-visnuveira og HIV. Lentiveira sýkir frumu. Mæði-visnuveira og HIV. Genaskipulag. Gangur sýkingar. Viðhelst í líkamanum þrátt fyrir öflugt ónæmissvar.
  • All About Eve

    All About Eve

    Touches of Film Noir . One key thing to notice in Macbeth is that Lady Macbeth gets downplayed until close to the end. Macbeth is the one that steals all of the attention with his bloodlust. This is quite common...
  • Chapter 18

    Chapter 18

    Chapter 18 Endocrine Glands and Hormones Introduction The human body has two types of glands: Exocrine glands contain cells that produce secretions transported through ducts Endocrine glands (ductless glands) secrete hormones directly into the bloodstream or to neighboring cells Introduction...
  • Periodic Table and Periodic Law

    Periodic Table and Periodic Law

    - The elements in each period have the same number of shells . Groups (families): vertical columns - The elements in each group have the same number of valence electrons . Group numbers 1-18 (new system) or A/B system (older)...
  • $Money$ in the Colony - Suffolk City Public Schools

    $Money$ in the Colony - Suffolk City Public Schools

    BARTER Trading or Exchanging of Goods and Services without the Use of Money Buy a good or service NOW Pay for it LATER Example: Credit Cards and Bills CREDIT: Buying a good or service now and paying for it later...
  • Chapter Eight - My Illinois State

    Chapter Eight - My Illinois State

    Classic Models of Persuasion:Social Judgment Theory. Developed by M. Sherif, C. Sherif, and colleagues. Proposes that statements about a particular "attitude object" can be arrayed to include latitudes of acceptance, rejection, and noncommitment. Attitude change will be influenced by how...
  • Health Equity Funders - Fhi 360

    Health Equity Funders - Fhi 360

    A sense that we need to define what exactly is entailed by health equity research, and expand what is constituted as health - education, residential segregation, etc. could all have health and equity implications ... Annie E. Casey, Kresge (less...
  • www.cforrestscience.com

    www.cforrestscience.com

    Convection Current Pg. 443. Is the movement of water that results from differences in density. Upwelling Pg. 444. Wind blows toward the equator along the northwest coast of South America and the west coast of North America. These winds cause...