Planetary Rings and the Cassini Mission Lecture #1
Mark R. Showalter SETI Institute
COSPAR WORKSHOP Wednesday, July 23, 2007
1 Jupiter Saturn
Uranus Neptune
2 Why Study Rings?
Orion Nebula in HST
3 Protoplanetary Disks in the Orion Nebula
4 Artist’s Conception of a Protoplanetary Disk
5 Cassini Crosses the Ring Plane
6 Cassini Crosses the Ring Plane
7 Cassini Crosses the Ring Plane
8 Cassini Approaches Saturn
http://saturn.jpl.nasa.gov/ http://saturn.jpl.nasa.gov/multimedia/images/raw/
9 10 Low-Gain Antenna High-Gain (1 of 2) Antenna
Magnetometer Boom
Radar Bay
Fields Radio/Plasma and Wave Subsystem Particles Antenna (1 of 3) Pallet
Remote Sensing Pallet Huygens Titan Probe
Radioisotope Thermoelectric Generator Engine (1 of 3) (1 of 2)
11 October 15, 1997
12 Saturn Arrival 1 July 2004
Jupiter Swingby 30 Dec 2000
Venus Swingby 24 June 1999 Venus Swingby Sun 26 April 1998
Launch Earth Swingby 15 Oct 1997 18 Aug 1999
13 Phoebe
(Best views from Voyager)
14 Saturn Orbit Insertion
15 16 B Ring at 150 meter resolution: There’s structure all the way down!
Voyager 2 image 3 km resolution
17 F Ring at Fine Resolution
18 A Ring, Outer Edge of the Encke Gap
Pan Wake
19 Outer A Ring Density Waves
20 Keeler Gap, Outer A Ring
21 Moons of Saturn Janus
Rhea
Mimas
22 Saturn’s North Pole
23 Views of Titan
IR wavelengths
Visual wavelengths
24 Radar Image
Titan Probe Camera 25 The View from Saturn’s Shadow
26 The View from Saturn’s Shadow
26 Ice Geysers on Enceladus
27 The Shadow of Enceladus in the E Ring
28 A new feature 200 km inward from the F ring core
29 What is this ?!?!? The aftermath of a ring impact?
30 Spokes in the B Ring
31 The Opposition Surge in the Rings
32 Satellite Mutual Event
33 Cassini Extended Mission has been approved by NASA: 2 more years and probably 4. 34 What Mission Work is Really Like...
Tour Plan Presentations
Science Planning Process Context
Long-Range Mission Planning Process
MP Updates MP Updates MP Updates MP Updates
Uplinked Tour Science and Sequences and SOP SOP Aftermarket SOP Update Sequencing R/T Commands Development Aftermarket Aftermarket Aftermarket PrAofcteersmsarket PAroftceersmsarket UpdatAef tPerromcMaePrskset Process Process ProcUepsdsates Process Process (SSPUroPc)ess
Integration/ Activity Conflict SPVT Tour Atlas Request Resolution Implementaton Process & Merge Process Process
Science Planning Process (SPP)
B. Paczkowski 4 3/03/2004 Science Planning Team
35
36
New Horizons at Jupiter February 28, 2007
http://pluto.jhuapl.edu/
37 Jupiter’s Storms February 27, 2007
False Color from IR images 1.25–2.5 µm
38 Low-Resolution Color Imaging
Io & Europa Together March 2, 2007
39 Active volcano on Io
40 Active volcano on Io
40 Jupiter’s Rings in backscatter
Boulders {
Dust
Metis
Adrastea
41 Clumps in Jupiter’s Ring, Trailing Adrastea
42 Backscatter
Forward-Scatter
Dust
43 Uranus Voyager Images, January 1986
True color Enhanced color http://photojournal.jpl.nasa.gov/
44 epsilon Uranian Rings in back-scattered light lambda delta gamma eta
beta alpha
4 5 6
45 Uranian dust belts in forward-scattered light
46 Ophelia
Two small moons “shepherd” the ε ring Cordelia
47 Uranus: August 2003
48 Uranus: August 2003
48 Recovery of “Perdita” Discovery of “Cupid” Orbit 1
Credit: Science Magazine/M. Showalter
49 Recovery of “Perdita” Orbit 2 Discovery of “Mab”
Credit: Science Magazine/M.
Showalter 50 Uranus: August 2003
Mab
51 Uranus: August 2003
Mab
µ ring ν ring
51 G Ring E Ring
Blue color indicates tinier dust particles
μ ring ν ring
52 Equinox 2007
2003
2005
2007 53 Uranian Ring Plane Crossing 2007–2008 6
4
Su ) b-S ° o
( la r La e 2 titu d de u t i t a L
c
i 0 r
t Jan Apr Jul Oct Jan Apr Jun n e c
o Sub-Earth Latitude t
e -2 n a l P
-4
2007 2008 -6 Date
54 The Uranian Ring System Through the Years:
Keck Telescope Adaptive Optics
D G E H B A 6 Z 5 4
July 2004 August 2006 May 2007
55