DOCSLIB.ORG

The Saturn System 1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Saturn System 1 GETTING TO KNOW SATURN LESSON The Saturn System 1 3 hrs Students learn the concept of a system and apply it to learning about the Saturn sys- tem. They work with a ready-made scale diagram of the Saturn system, including the planet, rings, and moons. MEETS NATIONAL The lesson prepares students to complete a SCIENCE EDUCATION STANDARDS: Venn diagram that compares and contrasts Unifying Concepts the Saturn and Earth–Moon systems in and Processes • Systems, order, terms of the systems’ components and and organization interactions. Composite of Voyager images of Saturn and some of the moons. Earth and Space Science PREREQUISITE SKILLS BACKGROUND INFORMATION • Earth in the Solar System Working in groups Background for Lesson Discussion, page 2 Drawing and interpreting system diagrams Questions, page 7 Measuring in millimeters Answers in Appendix 1, page 225 Computation (multiplication and division) 1–21: Saturn Completing a Venn diagram 22–34: Rings 35–50: Moons 51–55: Observing Saturn in the Sky EQUIPMENT, MATERIALS, AND TOOLS For the teacher Materials to reproduce Photocopier (for transparencies & copies) Figures 1–8 are provided at the end of Overhead projector this lesson. Chalkboard, whiteboard, or easel with FIGURE TRANSPARENCY COPIES paper; chalk or markers 1 1 1 per group Color image or video of Saturn (optional) 2 1 optional Basketball (optional) 3 1 per group For each group of 3 to 4 students 4 1 per group Chart paper (18" x 22"); color markers 5 1 per group Notebook paper; pencils; clear adhesive 6 1 per group tape; scissors; ruler with millimeter 7 optional divisions 8 1 per student Meter stick (optional) 1 Saturn Educator Guide • Cassini Program website — http://www.jpl.nasa.gov/cassini/educatorguide • EG-1999-12-008-JPL Background for Lesson Discussion LESSON • Moon–moon interactions include Epimetheus 1 Comparing the Saturn system to Earth’s system and Janus swapping orbits. (See Procedures & Activities, Part II, Step 3) • Moon–planet interactions include tidal forces • The Saturn system is farther from the Sun. between the moons and the planet. • The planet in the Saturn system is bigger. (Note: This can be discussed further if students • Saturn is a different color (butterscotch have learned something previously about tidal yellow). forces between Earth and the Moon. See the • Saturn is made mostly of gas instead of rock. Glossary.) • The Saturn system has rings. • The Saturn system has more than one moon. Examples of inputs and outputs in the • The Saturn and Earth systems are both Saturn system subsystems of the Solar System. (See Procedures & Activities, Part II, Step 10) • Both systems receive and reflect sunlight. • Both systems have at least one moon. Sunlight is both an input to and an output of • In both systems, gravity acts to keep the the Saturn system. As an input, the Sun heats moon(s) orbiting around the planet. the system, but because Saturn is so far away • In both systems, there are tidal forces between from the Sun, it is very cold compared with the planet and moon(s). Earth. As an output, reflected sunlight is seen when we observe Saturn and its rings and moons. In the same way, we see the reflected Examples of interactions in the Saturn light of the Moon from Earth. system (See Procedures & Activities, Part II, Step 10) It is possible that Saturn’s gravity captures aster- The basic parts of the Saturn system are the oids, comets, and meteorites from time to time. planet, rings, and moons. The relationships and These events are considered inputs to the sys- interactions among them are defined predomi- tem. The moon farthest from Saturn (Phoebe) nantly by gravity. The moons and ring particles may be a captured asteroid. Comets that passed of the Saturn system orbit Saturn just like the near Saturn may have collided with and broken planets and asteroids of the Solar System orbit up a moon, and played a role in the formation the Sun. Fundamental properties of a system of Saturn’s rings. arise from the interaction of its parts, not from the properties of the individual parts. Radio waves are another output of the Saturn system. The mechanisms behind some of • Moon–ring interaction include: Saturn’s emission of “light” in the radio-wave — Prometheus and Pandora “shepherding” portion of the electromagnetic spectrum are the F ring unknown. — Pan “clearing” the Encke Gap at the outer edge of the A ring — Enceladus possibly having ice geyers that create the E ring 2 Saturn Educator Guide • Cassini Program website — http://www.jpl.nasa.gov/cassini/educatorguide • EG-1999-12-008-JPL Lesson Plan LESSON Have the students select and diagram on 1 Part I: What Is a System? 3 notebook paper a system other than the Tell the students that diagrams are simple Solar System. 1 drawings that can show the basic organiza- Have students form groups with those who tion of a system. Demonstrate how to make 4 diagrams by drawing the Solar System, includ- have drawn different system diagrams. ing the Sun and planets with their labels, and Limit group size to four students. the planets’ orbital paths. For completion, title Give each group a sheet of chart paper, and the diagram (of course, it is not to scale). 5 have them attach their diagrams around the outside edge. Have the students record, in the JUPITER URANUS EARTH MERCURY SUN NEPTUNE MARS SATURN VENUS PLUTO The Solar System (not to scale). Ask students this question: How have you center of the paper, all the similarities they can 2 heard the word “system” used? List their find in their system diagrams. Guide students to responses on the chalkboard. Possible student consider questions such as — What do all the responses include: Solar System, school system, diagrams have in common? (For example: titles, computer system, stereo system, digestive sys- labels, or objects.) What do all the systems have tem, and so on. in common? (For example: parts, interconnec- tions and interactions among parts, boundaries, inputs, outputs, organizing principles, or According to the National Science Education Standards, forces.) a system is an organized group of related objects or components that form a whole. For example, systems can Have each group share their diagrams with 6 consist of organisms, machines, fundamental particles, the whole class. Discuss with students their galaxies, ideas, numbers, transportation, and education. understanding of systems. Guide them to recog- nize the various aspects of a system and the per- Systems have boundaries, components, flow (input and vasive nature of “systems” in our world, in the output), and interactions. Solar System, and in the Universe. 3 Saturn Educator Guide • Cassini Program website — http://www.jpl.nasa.gov/cassini/educatorguide • EG-1999-12-008-JPL Display the Saturn Ring System (Figure 2) Part II: Making Connections to Saturn 4 LESSON transparency. Discuss students’ observations 1 Have the students focus on the planet Sat- of the ring illustration. For example: How many 1 urn in the Solar System diagram you drew rings are there? Do the rings appear in alphabeti- for them. Note that Saturn is the sixth planet cal order from Saturn outward? How wide are from the Sun and that it has rings (as do all the rings relative to the planet and to the Earth– of the giant planets in the outer Solar System Moon system? which are composed primarily of gases). Re- Explain that the next part of the lesson will mind them that the Solar System diagram is 5 not to scale, that Saturn is really much larger involve looking at a close-up of a smaller than Earth, and that Saturn is approximately section of the rings, and show students the four 10 times farther from the Sun than is Earth. pages of the Saturn System Diagram (Figure 4). Inform the students that NASA has a spacecraft Detailed instructions for assembling the diagram called Cassini that will study Saturn (it was are shown in Figure 3. Tell students that the launched in 1997 and will arrive at Saturn in scaled Saturn on the diagram is about the size of 2004). a basketball. Show them how to tape together the Saturn System Diagram: Display the transparency of the Voyager 2 • Line up the center lines of each section Image of Saturn (Figure 1) to introduce the (labeled A, B,C, and D). look of Saturn and its rings. Tell students that • Use the arc of the G ring to estimate the Saturn is a large ball of gas and does not have a connection between Sections A and B. solid surface like Earth’s. Ask students to guess • Tape A and B together. what size Earth would be if placed next to Sat- • Line up C and D to B and tape together. urn in this image (they will work out the answer during a later activity). Note: Older or more advanced students can achieve a more Note: If you have a color image or video of Saturn, it can be accurate depiction of scaled distances to the moons outside used to further motivate students’ interest in Saturn. If you the A ring by following the directions in How to Assemble the have access to the World Wide Web, the Cassini website is an Saturn System Diagram. (For lower grade levels, this degree of excellent source of Saturn images (http://www.jpl.nasa.gov/ care in assembly is likely to take too much time away from the cassini/). There are also other exceptional websites — please main concept of the lesson.) see Appendix 5, Resources. Put students in an even number of small 6 Ask students to consider how Saturn’s sys- groups of 3 or 4.
Load more

Recommended publications
  • Arxiv:1912.09192V2 [Astro-Ph.EP] 24 Feb 2020
    Draft version February 25, 2020 Typeset using LATEX preprint style in AASTeX62 Photometric analyses of Saturn's small moons: Aegaeon, Methone and Pallene are dark; Helene and Calypso are bright. M. M. Hedman,1 P. Helfenstein,2 R. O. Chancia,1, 3 P. Thomas,2 E. Roussos,4 C. Paranicas,5 and A. J. Verbiscer6 1Department of Physics, University of Idaho, Moscow, ID 83844 2Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca NY 14853 3Center for Imaging Science, Rochester Institute of Technology, Rochester NY 14623 4Max Planck Institute for Solar System Research, G¨ottingen,Germany 37077 5APL, John Hopkins University, Laurel MD 20723 6Department of Astronomy, University of Virginia, Charlottesville, VA 22904 ABSTRACT We examine the surface brightnesses of Saturn's smaller satellites using a photometric model that explicitly accounts for their elongated shapes and thus facilitates compar- isons among different moons. Analyses of Cassini imaging data with this model reveals that the moons Aegaeon, Methone and Pallene are darker than one would expect given trends previously observed among the nearby mid-sized satellites. On the other hand, the trojan moons Calypso and Helene have substantially brighter surfaces than their co-orbital companions Tethys and Dione. These observations are inconsistent with the moons' surface brightnesses being entirely controlled by the local flux of E-ring par- ticles, and therefore strongly imply that other phenomena are affecting their surface properties. The darkness of Aegaeon, Methone and Pallene is correlated with the fluxes of high-energy protons, implying that high-energy radiation is responsible for darkening these small moons. Meanwhile, Prometheus and Pandora appear to be brightened by their interactions with nearby dusty F ring, implying that enhanced dust fluxes are most likely responsible for Calypso's and Helene's excess brightness.
    [Show full text]
  • Cassini Update
    Cassini Update Dr. Linda Spilker Cassini Project Scientist Outer Planets Assessment Group 22 February 2017 Sols%ce Mission Inclina%on Profile equator Saturn wrt Inclination 22 February 2017 LJS-3 Year 3 Key Flybys Since Aug. 2016 OPAG T124 – Titan flyby (1584 km) • November 13, 2016 • LAST Radio Science flyby • One of only two (cf. T106) ideal bistatic observations capturing Titan’s Northern Seas • First and only bistatic observation of Punga Mare • Western Kraken Mare not explored by RSS before T125 – Titan flyby (3158 km) • November 29, 2016 • LAST Optical Remote Sensing targeted flyby • VIMS high-resolution map of the North Pole looking for variations at and around the seas and lakes. • CIRS last opportunity for vertical profile determination of gases (e.g. water, aerosols) • UVIS limb viewing opportunity at the highest spatial resolution available outside of occultations 22 February 2017 4 Interior of Hexagon Turning “Less Blue” • Bluish to golden haze results from increased production of photochemical hazes as north pole approaches summer solstice. • Hexagon acts as a barrier that prevents haze particles outside hexagon from migrating inward. • 5 Refracting Atmosphere Saturn's• 22unlit February rings appear 2017 to bend as they pass behind the planet’s darkened limb due• 6 to refraction by Saturn's upper atmosphere. (Resolution 5 km/pixel) Dione Harbors A Subsurface Ocean Researchers at the Royal Observatory of Belgium reanalyzed Cassini RSS gravity data• 7 of Dione and predict a crust 100 km thick with a global ocean 10’s of km deep. Titan’s Summer Clouds Pose a Mystery Why would clouds on Titan be visible in VIMS images, but not in ISS images? ISS ISS VIMS High, thin cirrus clouds that are optically thicker than Titan’s atmospheric haze at longer VIMS wavelengths,• 22 February but optically 2017 thinner than the haze at shorter ISS wavelengths, could be• 8 detected by VIMS while simultaneously lost in the haze to ISS.
    [Show full text]
  • Moons Phases and Tides
    Moon’s Phases and Tides Moon Phases Half of the Moon is always lit up by the sun. As the Moon orbits the Earth, we see different parts of the lighted area. From Earth, the lit portion we see of the moon waxes (grows) and wanes (shrinks). The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the sky The Moon passes through four major shapes during a cycle that repeats itself every 29.5 days. The phases always follow one another in the same order: New moon Waxing Crescent First quarter Waxing Gibbous Full moon Waning Gibbous Third (last) Quarter Waning Crescent • IF LIT FROM THE RIGHT, IT IS WAXING OR GROWING • IF DARKENING FROM THE RIGHT, IT IS WANING (SHRINKING) Tides • The Moon's gravitational pull on the Earth cause the seas and oceans to rise and fall in an endless cycle of low and high tides. • Much of the Earth's shoreline life depends on the tides. – Crabs, starfish, mussels, barnacles, etc. – Tides caused by the Moon • The Earth's tides are caused by the gravitational pull of the Moon. • The Earth bulges slightly both toward and away from the Moon. -As the Earth rotates daily, the bulges move across the Earth. • The moon pulls strongly on the water on the side of Earth closest to the moon, causing the water to bulge. • It also pulls less strongly on Earth and on the water on the far side of Earth, which results in tides. What causes tides? • Tides are the rise and fall of ocean water.
    [Show full text]
  • 7 Planetary Rings Matthew S
    7 Planetary Rings Matthew S. Tiscareno Center for Radiophysics and Space Research, Cornell University, Ithaca, NY, USA 1Introduction..................................................... 311 1.1 Orbital Elements ..................................................... 312 1.2 Roche Limits, Roche Lobes, and Roche Critical Densities .................... 313 1.3 Optical Depth ....................................................... 316 2 Rings by Planetary System .......................................... 317 2.1 The Rings of Jupiter ................................................... 317 2.2 The Rings of Saturn ................................................... 319 2.3 The Rings of Uranus .................................................. 320 2.4 The Rings of Neptune ................................................. 323 2.5 Unconfirmed Ring Systems ............................................. 324 2.5.1 Mars ............................................................... 324 2.5.2 Pluto ............................................................... 325 2.5.3 Rhea and Other Moons ................................................ 325 2.5.4 Exoplanets ........................................................... 327 3RingsbyType.................................................... 328 3.1 Dense Broad Disks ................................................... 328 3.1.1 Spiral Waves ......................................................... 329 3.1.2 Gap Edges and Moonlet Wakes .......................................... 333 3.1.3 Radial Structure .....................................................
    [Show full text]
  • JUICE Red Book
    ESA/SRE(2014)1 September 2014 JUICE JUpiter ICy moons Explorer Exploring the emergence of habitable worlds around gas giants Definition Study Report European Space Agency 1 This page left intentionally blank 2 Mission Description Jupiter Icy Moons Explorer Key science goals The emergence of habitable worlds around gas giants Characterise Ganymede, Europa and Callisto as planetary objects and potential habitats Explore the Jupiter system as an archetype for gas giants Payload Ten instruments Laser Altimeter Radio Science Experiment Ice Penetrating Radar Visible-Infrared Hyperspectral Imaging Spectrometer Ultraviolet Imaging Spectrograph Imaging System Magnetometer Particle Package Submillimetre Wave Instrument Radio and Plasma Wave Instrument Overall mission profile 06/2022 - Launch by Ariane-5 ECA + EVEE Cruise 01/2030 - Jupiter orbit insertion Jupiter tour Transfer to Callisto (11 months) Europa phase: 2 Europa and 3 Callisto flybys (1 month) Jupiter High Latitude Phase: 9 Callisto flybys (9 months) Transfer to Ganymede (11 months) 09/2032 – Ganymede orbit insertion Ganymede tour Elliptical and high altitude circular phases (5 months) Low altitude (500 km) circular orbit (4 months) 06/2033 – End of nominal mission Spacecraft 3-axis stabilised Power: solar panels: ~900 W HGA: ~3 m, body fixed X and Ka bands Downlink ≥ 1.4 Gbit/day High Δv capability (2700 m/s) Radiation tolerance: 50 krad at equipment level Dry mass: ~1800 kg Ground TM stations ESTRAC network Key mission drivers Radiation tolerance and technology Power budget and solar arrays challenges Mass budget Responsibilities ESA: manufacturing, launch, operations of the spacecraft and data archiving PI Teams: science payload provision, operations, and data analysis 3 Foreword The JUICE (JUpiter ICy moon Explorer) mission, selected by ESA in May 2012 to be the first large mission within the Cosmic Vision Program 2015–2025, will provide the most comprehensive exploration to date of the Jovian system in all its complexity, with particular emphasis on Ganymede as a planetary body and potential habitat.
    [Show full text]
  • The Orbits of Saturn's Small Satellites Derived From
    The Astronomical Journal, 132:692–710, 2006 August A # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE ORBITS OF SATURN’S SMALL SATELLITES DERIVED FROM COMBINED HISTORIC AND CASSINI IMAGING OBSERVATIONS J. N. Spitale CICLOPS, Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301; [email protected] R. A. Jacobson Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 C. C. Porco CICLOPS, Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 and W. M. Owen, Jr. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 Received 2006 February 28; accepted 2006 April 12 ABSTRACT We report on the orbits of the small, inner Saturnian satellites, either recovered or newly discovered in recent Cassini imaging observations. The orbits presented here reflect improvements over our previously published values in that the time base of Cassini observations has been extended, and numerical orbital integrations have been performed in those cases in which simple precessing elliptical, inclined orbit solutions were found to be inadequate. Using combined Cassini and Voyager observations, we obtain an eccentricity for Pan 7 times smaller than previously reported because of the predominance of higher quality Cassini data in the fit. The orbit of the small satellite (S/2005 S1 [Daphnis]) discovered by Cassini in the Keeler gap in the outer A ring appears to be circular and coplanar; no external perturbations are appar- ent. Refined orbits of Atlas, Prometheus, Pandora, Janus, and Epimetheus are based on Cassini , Voyager, Hubble Space Telescope, and Earth-based data and a numerical integration perturbed by all the massive satellites and each other.
    [Show full text]
  • Chapter 14. Saturn and Its Attendants
    14. Saturn and Its Attendants 1 Chapter 14. Saturn and Its Attendants Figure 14.3. A Voyager portrait. Note. In this section we survey physical properties of Saturn. Note. Some general facts about Saturn include: Orbital Period 29.5 years Rotation Period 10 hours 40 minutes Tilt of Axis 26◦ Mass 95 times Earth’s mass Surface Gravity 1.13 of Earth’s Albedo 34% Satellites 17 known Galileo was the first to see Saturn’s rings. Huygens explained them as rings and discovered the moon Titan. Cassini observed gaps in the rings and discovered four satellites. Saturn also has differential rotation, and a composition similar to that of Jupiter. 14. Saturn and Its Attendants 2 Note. Saturn is similar to Jupiter, with belts and zones, but the contrast on Saturn is less extreme. Rising and descending gas combines with rapid rotation to form strips circling the planet, as on Jupiter. The interior is similar to Jupiter, with a very thick layer of clouds, a layer of liquid hydrogen and helium, a layer of liquid metallic hydrogen, and a rock-and-ice solid core. Saturn puts out 1.8 times as much energy as it takes in, the excess is from continued differentiation (the heavy stuff sinks and releases energy). Saturn has a magnetic field slightly stronger than Earth’s and its magnetosphere fluctuates in size with solar activity. Figure 14.7. The internal structure of Saturn. Note. There is evidence for as many as 22 satellites. Of primary concern are (in no particular order): Titan. It is only one of two satellites that has an atmosphere.
    [Show full text]
  • Dwarf Planet Ceres
    Dwarf Planet Ceres drishtiias.com/printpdf/dwarf-planet-ceres Why in News As per the data collected by NASA’s Dawn spacecraft, dwarf planet Ceres reportedly has salty water underground. Dawn (2007-18) was a mission to the two most massive bodies in the main asteroid belt - Vesta and Ceres. Key Points 1/3 Latest Findings: The scientists have given Ceres the status of an “ocean world” as it has a big reservoir of salty water underneath its frigid surface. This has led to an increased interest of scientists that the dwarf planet was maybe habitable or has the potential to be. Ocean Worlds is a term for ‘Water in the Solar System and Beyond’. The salty water originated in a brine reservoir spread hundreds of miles and about 40 km beneath the surface of the Ceres. Further, there is an evidence that Ceres remains geologically active with cryovolcanism - volcanoes oozing icy material. Instead of molten rock, cryovolcanoes or salty-mud volcanoes release frigid, salty water sometimes mixed with mud. Subsurface Oceans on other Celestial Bodies: Jupiter’s moon Europa, Saturn’s moon Enceladus, Neptune’s moon Triton, and the dwarf planet Pluto. This provides scientists a means to understand the history of the solar system. Ceres: It is the largest object in the asteroid belt between Mars and Jupiter. It was the first member of the asteroid belt to be discovered when Giuseppe Piazzi spotted it in 1801. It is the only dwarf planet located in the inner solar system (includes planets Mercury, Venus, Earth and Mars). Scientists classified it as a dwarf planet in 2006.
    [Show full text]
  • Enceladus, Moon of Saturn
    National Aeronautics and and Space Space Administration Administration Enceladus, Moon of Saturn www.nasa.gov Enceladus (pronounced en-SELL-ah-dus) is an icy moon of Saturn with remarkable activity near its south pole. Covered in water ice that reflects sunlight like freshly fallen snow, Enceladus reflects almost 100 percent of the sunlight that strikes it. Because the moon reflects so much sunlight, the surface temperature is extremely cold, about –330 degrees F (–201 degrees C). The surface of Enceladus displays fissures, plains, corrugated terrain and a variety of other features. Enceladus may be heated by a tidal mechanism similar to that which provides the heat for volca- An artist’s concept of Saturn’s rings and some of the icy moons. The ring particles are composed primarily of water ice and range in size from microns to tens of meters. In 2004, the Cassini spacecraft passed through the gap between the F and G rings to begin orbiting Saturn. noes on Jupiter’s moon Io. A dramatic plume of jets sprays water ice and gas out from the interior at ring material, coating itself continually in a mantle Space Agency. The Jet Propulsion Laboratory, a many locations along the famed “tiger stripes” at of fresh, white ice. division of the California Institute of Technology, the south pole. Cassini mission data have provided manages the mission for NASA. evidence for at least 100 distinct geysers erupting Saturn’s Rings For images and information about the Cassini on Enceladus. All of this activity, plus clues hidden Saturn’s rings form an enormous, complex struc- mission, visit — http://saturn.jpl.nasa.gov/ in the moon’s gravity, indicates that the moon’s ture.
    [Show full text]
  • Lecture 12 the Rings and Moons of the Outer Planets October 15, 2018
    Lecture 12 The Rings and Moons of the Outer Planets October 15, 2018 1 2 Rings of Outer Planets • Rings are not solid but are fragments of material – Saturn: Ice and ice-coated rock (bright) – Others: Dusty ice, rocky material (dark) • Very thin – Saturn rings ~0.05 km thick! • Rings can have many gaps due to small satellites – Saturn and Uranus 3 Rings of Jupiter •Very thin and made of small, dark particles. 4 Rings of Saturn Flash movie 5 Saturn’s Rings Ring structure in natural color, photographed by Cassini probe July 23, 2004. Click on image for Astronomy Picture of the Day site, or here for JPL information 6 Saturn’s Rings (false color) Photo taken by Voyager 2 on August 17, 1981. Click on image for more information 7 Saturn’s Ring System (Cassini) Mars Mimas Janus Venus Prometheus A B C D F G E Pandora Enceladus Epimetheus Earth Tethys Moon Wikipedia image with annotations On July 19, 2013, in an event celebrated the world over, NASA's Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth. 8 Newly Discovered Saturnian Ring • Nearly invisible ring in the plane of the moon Pheobe’s orbit, tilted 27° from Saturn’s equatorial plane • Discovered by the infrared Spitzer Space Telescope and announced 6 October 2009 • Extends from 128 to 207 Saturnian radii and is about 40 radii thick • Contributes to the two-tone coloring of the moon Iapetus • Click here for more info about the artist’s rendering 9 Rings of Uranus • Uranus -- rings discovered through stellar occultation – Rings block light from star as Uranus moves by.
    [Show full text]
  • The Rings and Inner Moons of Uranus and Neptune: Recent Advances and Open Questions
    Workshop on the Study of the Ice Giant Planets (2014) 2031.pdf THE RINGS AND INNER MOONS OF URANUS AND NEPTUNE: RECENT ADVANCES AND OPEN QUESTIONS. Mark R. Showalter1, 1SETI Institute (189 Bernardo Avenue, Mountain View, CA 94043, mshowal- [email protected]! ). The legacy of the Voyager mission still dominates patterns or “modes” seem to require ongoing perturba- our knowledge of the Uranus and Neptune ring-moon tions. It has long been hypothesized that numerous systems. That legacy includes the first clear images of small, unseen ring-moons are responsible, just as the nine narrow, dense Uranian rings and of the ring- Ophelia and Cordelia “shepherd” ring ε. However, arcs of Neptune. Voyager’s cameras also first revealed none of the missing moons were seen by Voyager, sug- eleven small, inner moons at Uranus and six at Nep- gesting that they must be quite small. Furthermore, the tune. The interplay between these rings and moons absence of moons in most of the gaps of Saturn’s rings, continues to raise fundamental dynamical questions; after a decade-long search by Cassini’s cameras, sug- each moon and each ring contributes a piece of the gests that confinement mechanisms other than shep- story of how these systems formed and evolved. herding might be viable. However, the details of these Nevertheless, Earth-based observations have pro- processes are unknown. vided and continue to provide invaluable new insights The outermost µ ring of Uranus shares its orbit into the behavior of these systems. Our most detailed with the tiny moon Mab. Keck and Hubble images knowledge of the rings’ geometry has come from spanning the visual and near-infrared reveal that this Earth-based stellar occultations; one fortuitous stellar ring is distinctly blue, unlike any other ring in the solar alignment revealed the moon Larissa well before Voy- system except one—Saturn’s E ring.
    [Show full text]
  • The Solar System Cause Impact Craters
    ASTRONOMY 161 Introduction to Solar System Astronomy Class 12 Solar System Survey Monday, February 5 Key Concepts (1) The terrestrial planets are made primarily of rock and metal. (2) The Jovian planets are made primarily of hydrogen and helium. (3) Moons (a.k.a. satellites) orbit the planets; some moons are large. (4) Asteroids, meteoroids, comets, and Kuiper Belt objects orbit the Sun. (5) Collision between objects in the Solar System cause impact craters. Family portrait of the Solar System: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, (Eris, Ceres, Pluto): My Very Excellent Mother Just Served Us Nine (Extra Cheese Pizzas). The Solar System: List of Ingredients Ingredient Percent of total mass Sun 99.8% Jupiter 0.1% other planets 0.05% everything else 0.05% The Sun dominates the Solar System Jupiter dominates the planets Object Mass Object Mass 1) Sun 330,000 2) Jupiter 320 10) Ganymede 0.025 3) Saturn 95 11) Titan 0.023 4) Neptune 17 12) Callisto 0.018 5) Uranus 15 13) Io 0.015 6) Earth 1.0 14) Moon 0.012 7) Venus 0.82 15) Europa 0.008 8) Mars 0.11 16) Triton 0.004 9) Mercury 0.055 17) Pluto 0.002 A few words about the Sun. The Sun is a large sphere of gas (mostly H, He – hydrogen and helium). The Sun shines because it is hot (T = 5,800 K). The Sun remains hot because it is powered by fusion of hydrogen to helium (H-bomb). (1) The terrestrial planets are made primarily of rock and metal.
    [Show full text]