PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Planetary Rings (cont.) + Galilean Satellites.

Slides:



Advertisements
Similar presentations
Chapter 12 Saturn Chapter 12 opener. The number of known moons in the solar system increased rapidly during the late 1990s. Better telescopes enabled astronomers.
Advertisements

Planetary Rings All four jovian planets have ring systems girdling their equators. Many of the inner jovian moons orbit close to (or even within) the parent.
Unit 2 Lesson 5 The Gas Giant Planets
 The outer planets are called Jovian or Jupiter- like.  These planets are made of gas and are several times more massive than the Earth.  The Jovian.
Jupiter and Saturn’s Satellites of Fire and Ice Chapter Fifteen.
Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.
Planetary Ring Systems. Rings: A B C 4/4 Giant Worlds Have Rings Jupiter: broad, dark, fine particles Saturn: broad, bright, complex, icy particles.
General Astronomy Rings ‘n’ Things. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions,
Moons of the Outer Planets The outer planets have large retinues of moons, including objects as big as Mercury (Ganymede,Titan) and with an atmosphere.
Announcements Tests will be graded by Wednesday Due to server problems, you may turn in Homework 6 as late as Wednesday. Pick up Homework 7 (due Monday)
Moons of the solar system: 3 categories: 7 large (each is distinctive) 12 medium-size many small (most are captured)
NJIT Physics 320: Astronomy and Astrophysics – Lecture XIII Carsten Denker Physics Department Center for Solar–Terrestrial Research.
Chapter 7 The Outer Planets. What do you think? Is Jupiter a “failed star” or almost a star? What is Jupiter’s Great Red Spot? Does Jupiter have continents.
The Gas Giants Astronomy 311 Professor Lee Carkner Lecture 16.
By Julie Bingaman 5th Grade
WARM UP What two things determine the strength of an object’s gravitational force?
 Satellites – natural or artificial bodies that revolve around larger bodies such as planets.
Our Solar System Mrs. Lacks 6th Grade.
Lesson 8a Moons, Asteroids and Rings. Europa These interactions also keep Europa in a slight elliptical orbit as well. But since Europa is farther from.
Lecture 34 The Outer Planets. The Moon. The Origin of the Moon The Outer Planet Family Chapter 16.9 
The Jovian Planets Chapter 7. Topics Jupter, Saturn, Uranus, Neptune How do we know? Why do we care? What is common about the outer planets? What is peculiar.
1. Helium rain lower temperatures of Saturn's interior allow helium to come out of solution with hydrogen and form droplets, these droplets fall toward.
The Jovian Planets, Part II Saturn. SATURN The God of Agriculture.
Jupiter and Saturn: Lords of the Planets Chapter Fourteen.
The Gas Giant Planets Chapter 29 Section 3
Our Solar System Chapter 28.
By: Ian McGorray Kevin Bhasin Gnana Umpathy Dean Bizga
Chapter 6.
Our Solar System.
3 rd brightest object in night sky Alternating light & dark bands Giant Red Spot Galilean moons (Io, Callisto, Ganymede, Europa)
Jovian Planets: Jupiter and Saturn Shortened Version Feb 15, 2011.
Gas Giants. The four outer planets are: Jupiter Saturn Uranus Neptune.
Planetary Rings. Rings are swarms of orbiting particles Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring.
Jupiter and Saturn: Lords of the Planets Chapter Fourteen.
Outer Planets  Comparative Giant Planets  Jupiter  Saturn  Uranus  Neptune  Gravity  Tidal Forces Sept. 25, 2002.
The Sun & The Solar System. Structure of the Sun The Sun has layers which can be compared to the Earth’s core, mantle, crust, and atmosphere All of these.
The Outer Planets The Gas Giants.
Rotation period as fast as Jupiter, as well as differential rotation rates at poles and equator.
All Late Work Due by 12/18/15.
AST 111 Lecture 21 Jovian Worlds II. The Jovian Moons Numerous! Galilean Moons.
Interior - Internal Heating - Saturn reradiates three times as much energy as it absorbs; therefore, there must be an internal heat source.
Resonances. Resonances I. Orbital Resonances A. Definition: An orbital resonance occurs when two orbiting bodies exert a _______ and ________ gravitational.
Earth Science Chapter 17 Sections 1-2
Moon and Rings 13. Astronomy Picture of the Day Moons of Jovian Planets Jupiter alone has over 60 We will focus on large: Diameter > 2,500 km Why study.
PTYS/ASTR 206Saturn / Rings 4/5/07 Saturn … and Planetary Rings.
Today’s APODAPOD  Chapter 9 – Outer Planets  Quiz 8 this week ONLINE Friday  Kirkwood TONIGHT??, 7-9PM  Homework due FRIDAY The Sun Today A100 Saturn.
The Outer Planets Section Standard e. Students know the appearance, general composition, relative position and size, an motion of objects.
Moons and Rings. Jupiter’s Moons Jupiter is surrounded by 67 satellites. –Four large Galilean satellites –At least 16 over 5 km Galilean moons Captured.
Bit of Administration …. ReadingReading –BSNV Chap. 13 PortfoliosPortfolios –Due Thursday, April 29, because of possible TAA strike Put in box outside.
Astronomy 1010 Planetary Astronomy Fall_2015 Day-38.
Universe Tenth Edition Chapter 12: Jupiter and Saturn: Lords of the Planets Roger Freedman Robert Geller William Kaufmann III.
Maddie Barrett, Rachel Bell, and Rachel Bibb
Planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune Lunar and Solar Eclipses.
The Solar System: An Insider’s Guide Thursday! The Gas Giants,… and one more!
Chapter 15: The Solar System The Solar System The Planets.
Unit 7: The Outer Planets Mr. Ross Brown Brooklyn School for Law and Technology.
The Outer Planets. Discussion questions Compare and contrast the inner and outer planets? Compare and contrast the inner and outer planets? Why have we.
Resonances I. Orbital Resonances A. Definition: An orbital resonance occurs when two orbiting bodies exert a _______ and ________ gravitational influence.
Section 3: The Outer Planets
© 2017 Pearson Education, Inc.
The Solar System Lesson 6 Jupiter and Saturn
Interior - Internal Heating - Saturn reradiates three times as much energy as it absorbs; therefore, there must be an internal heat source.
Review: the giant planets and their moons
Essential Question What do we know about the ring systems of the gas giants in our solar system.
Astronomy 405 Solar System and ISM
Tides & Rings.
Section 3: The Outer Planets
Jovian Planet Moons and Rings
Astronomy Picture of the Day
Presentation transcript:

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Planetary Rings (cont.) + Galilean Satellites

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Announcements Reading Assignment –Finish Chapter 15 5 th homework due Thursday. Reminder about term paper – due April 17. –A sample “ planet fact sheet ” has been posted on the website –Details of turnitin.com Go to Click on “ new users ” Usertype  student Class ID: Password: Section2 Mission Updates? Next study-group session is tomorrow, from 10:30AM-12:00Noon – in room 330.

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 All Rings Have Gaps: Why?

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Rings, Gaps, and Resonances Gaps can occur in rings because the positions of particles in that ring are in a resonance with the planet and a moon Example: The Cassini division is located at a point that is in a 2:1 resonance with Saturn’s moon Mimas –Note that it is not completely devoid of particles!! The Cassini division between Saturn’s A and B rings

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 The gaps in rings are similar to Kirkwood gaps –Gaps in the number of asteroids in the asteroid belt –We will discuss this more in two weeks Distribution of asteroid periods showing gaps, like in planetary rings

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Cassini Found Density Waves in Saturn’s Rings Cassini images of spiral density waves in Saturn’s Rings

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Shepherd moons Small moons can also act to “shepherd” the ring particles (by gravity) into certain locations. Such moons are known as shepherd moons Saturn may have many undiscovered shepherd satellites Saturn’s faint F ring, which is just outside the A ring, is kept narrow by the gravitational pull of shepherd satellites

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Moons can even orbit a planet within one of the gaps in the rings, as in the case of Saturn’s moon Pan which orbits within the Encke gap

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Different parts of the Rings have different colors Different ring colors are caused by light scattering off of different sized particles –Light scattering depends on the size and composition of the particles in the ring The outer ring of Uranus has a moon embedded in it. The moon sweeps up larger pieces of material, leaving dust. Dust more effectively scatters blue light

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 The Color of Saturn’s Rings reveal that the ring particles do not migrate outside of their orbits Voyager 1 image Colors are strongly enhanced Cassini image Natural color

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 The Roche Limit Particles in a ring never coalesce to form a moon. –Planetary rings are within the Roche limit of the planet. Tidal forces are greater than the gravitational forces among the ring particles Question: why don’t the ring particles (chunks of ice and rock) break apart?

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 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 the history of Solar System

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Saturn’s Rings Most spectacular –Most massive (by 10 5 ) –Brightest albedo of 0.8 –The planet itself has an albedo of 0.5 Probably composed of ices –Youngest? –Sizes of the particles range from micrometers to a about ten meters Besides gaps, get spokes, waves

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Earth-based observations reveal three broad rings encircling Saturn

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Spokes in Saturn’s Rings Voyager I found changing dark structures (directed outward) in the rings. – given the term "spokes" They rotate with the magnetic field It has been proposed that electrostatic repulsion between ring particles may play a role.

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Jupiter and Saturn’s Moons

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Galilean Satellites

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Earth-based views Easily seen through a small telescope –Even binoculars Their movement can be seen throughout the night –They make shadows on Jupiter when they transit –They can also disappear behind Jupiter during an occulation

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Made by amateur -- Antonio Cidado (the movie was made using individual frames taken during a single night’s observing)

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Galilean Satellites and Kepler’s Laws Jupiter’s moons obey Kepler’s laws, just as the planets do in orbit about the Sun. –The orbital period is related to the semi-major axis (Newton’s form of Kepler’s 3 rd law) –Note that this is slightly DIFFERENT in form from what we used for the planets (why?)

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Orbital Resonances among Galilean Satelites Io, Europa, and Ganymede are in an orbital resonance such their orbital periods are in the proportion 1:2:4 –Io revolves around Jupiter twice for every complete orbit of Europa –Europa revolves around Jupiter twice for every complete orbit of Ganymede Io completes 4 orbits in this time

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Jupiter’s Satellites IoEuropaGanymedeCallisto Distance (J. radii) Period (days) Mass (Lunar) Density (g/cc)

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 You may notice … Io’s orbital period: days Europa’s orbital period: days but … 3.551/1.769 = ??? (not 2) We know that the orbital resonance is exactly 1:2. So what is the explanation for this apparent discrepancy? (The answer is subtle and you are not required to know it)

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Jupiter’s Satellites IoEuropaGanymedeCallisto Distance (J. radii) Period (days) Mass (Lunar) Density (g/cc)

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 Solar-system in Miniature ? The density of the Galilean satellites decreases with distance from Jupiter This is analogous to planets in the solar system –Close to the Sun are the Terrestrial planets (high density) –Farther away are the Gas Giants (low density) Planet densities

PTYS/ASTR 206Rings / Galilean Satellites 4/10/07 The Galilean satellites probably formed in a similar fashion to our solar system but on a smaller scale