Hubble OPAL Observations of Uranus and Neptune: 2014-2019

Total Page:16

File Type:pdf, Size:1020Kb

Hubble OPAL Observations of Uranus and Neptune: 2014-2019 https://ntrs.nasa.gov/search.jsp?R=20200000682 2020-03-28T18:47:38+00:00Z Hubble OPAL Amy Simon Observations (NASA GSFC) Michael H Wong of Uranus and (U.C. Berkeley) Neptune: Glenn Orton 2014-2019 (Caltech/JPL) Hubble Outer Planets Atmospheres • Legacy (OPAL) program Yearly Hubble (UV-Vis) imaging of the outer planets; two global maps per planet, began in 2014 with Uranus, 2015 for Neptune and Jupiter, 2018 for Saturn Trend changes in: Uranus Neptune brightness, HSTWFC3/UVIS HSTWFC3/UVIS cloud activity, F547M F657N 2D and zonal wind fields, F763M ["C'/~C\1 storm size, color, other changes 1 · b-,,. ._) 1,/: Serendipitous events All data are public, Maps are posted at STScI https://archive.stsci.edu/prepds/opal/ Simon et al. 2015 ApJ 812, 55 MAPS Neptune 2019 Uranus 2019 Generated in 5 continuum filters: • F467, F547, F657, F763, F845 2 methane absorption bands: • F619, F727 2014 Uranus 2017 Polar haze has continued to brighten Small storm activity 2019 Toledo et al. 2019 Icarus 333, 1-11 Toledo et al. 2018 Geophys. Res. Letters 45, 5329-5335 E. 2015.71 : RGB I. 2015.71 : F467M -20 -20 _ -30 _-30 Neptune "' "' ~ -40 ~ -40 -8 -8 ~ -50 ~ -50 1ij 1ij -' -60 -' -60 30 20 10 0 -10 -20 30 20 10 0 -10 -20 West Longitude (deg) West Longitude (deg) F. 2016.37: RGB J. 2016.37: F467M -20 -20 _-30 -g, -30 g, :9.., -40 :9.-40., "O "O a -50 ~ -50 ~ .§ -60 -60 -70 155 140 125 110 170 155 140 125 110 It’s all about the storms! Longitude (deg) Longilude (deg) G. 2016.76: RGB K. 2016.76: F467M -20 -20 Hubble’s high spatial resolution at short - .30 _-30 I., -40 I., -40 wavelengths allows us to see dark vortices ] -50 ] -50 ~ -60 ~ -60 not otherwise visible -70 175 160 145 130 115 160 145 130 115 Longitude (deg) Longitude (deg) H. 2017.76: RGB L. 2017.76: F467M New storm first seen in 2015 (SDS-2015) -20 -20 _-30 g, -g, -30 Moved poleward and dissipated by 2018 :9.., -40 :9.., -40 ~ -50 ] -50 j -60 ~ -60 150 135 120 105 150 135 120 105 Longitude (deg) Longttude (deg) 0.63 0.76 Wong et al. 2018 Astronomical Journal 155, 117 Neptune, cont. Voyager 1989 Hubble 2018 Another large storm found in 2018 (NDS-2018) (C) Similar in size and drift rate as the i 20 Voyager Great Dark Spot, even ::, ~ 10 though opposite hemispheres HST/UVIS Nov. 20 18 F467M Data from prior years allows a look 90 80 70 60 50 40 30 20 90 80 70 60 50 40 30 20 West Longitude (deg) West Longitude (deg) Voyager 1989 at cloud activity in the region over 0.75 the preceding years (D) 0.70 ~ C: <3 0.65 .>: Cl) 0 0.60 HST/UVIS Nov. 2018 F467M 0.55 - ~~~~~-------~~~~~-------~~~~~------- 90 80 70 60 50 40 30 20 West Longitude (deg) 7 October 2017 10 September 2018 Long coverage allowed us to track likely pre-cursor clouds to this storm forming May be able to use shape to determine deeper atmosphere structure goo 1.5x10-4 60° ~ 1.0x10-4 --s 30° --5 0.5x10-4 Sromovsky et al. (1993) wind shear oo 0 NDS-2018 asRect ratio 4 -30° -0.5x10- 1.0 1.5 3.0 -60° Simon, Wong & Hsu 2019 GRL 46, 3108-3113 -90° Frequency and Lifetime of Dark Spots Counted dark spots seen by Voyager (2) and Hubble (4) Time coverage is sparse, but * 100 * * * * -C -(I) maximum lifetimes could be I •. • • ~ constrained to 1 - 6 years s(I) 80 ~ Also looked at time coverage :0 cu 60 .0 and how many observations ,._0 0.. had no spots detected Cl) 40 .ECl) ,._I Monte Carlo simulations then ~ (I) 20 Post-Voyager- '\ C -. • .. campaign I, run to determine the likelihood Cl) ••• -. --Cl) . ~ a of a spot forming, and of ~ 0 - - failing to detect it, based on 1995•• 2000I II " 2010I I 2015I these observing statistics Can’t see a spot, if not observing! Hsu, Wong & Simon 2019 AJ 157, 152 Summary Seeing a lot of activity on both Ice Giants Uranus Smaller, high latitude, storms persist Polar haze continues to brighten over time Neptune Two new dark vortices detected Occurrence of a spot every 4-6 years, with lifetimes from 1 to 6 years Frequent observations are invaluable, but any future mission will see interesting atmospheric activity, regardless of timing A Neptune orbiter with a lifetime of 6 years would be ideal for ensuring a dark vortex is observed.
Recommended publications
  • The Mystery and Majesty
    The mystery and majesty Nearly 40 years after THE SPACE AGE BLASTED off when the Soviet Union launched the Voyager 2 visited Uranus world’s first artificial satellite in 1957. Since then, humanity has explored our cosmic and Neptune, scientists are backyard with vigor — and yet two planets have fallen to the planetary probe wayside. eager for new expeditions. In the 63 years since Sputnik, humanity has only visited Neptune and Uranus once BY JOEL DAVIS — when Voyager 2 flew past Uranus in January 1986 and Neptune in August 1989 40 ASTRONOMY • DECEMBER 2020 of the ICE GIANTS — and even that wasn’t entirely pre- interstellar mission, more than a dozen pro- In 1781, Uranus became the first planet planned. The unmitigated success of posals have been offered for return missions ever discovered using a telescope. Nearly 200 years later, Voyager 2 Voyager 1 and 2 on their original mission to one or both ice giants. So far, none have became the first spacecraft to visit to explore Jupiter and Saturn earned the made it past the proposal stage due to lack Uranus and Neptune, in 1986 and 1989 respectively. NASA/JPL twin spacecrafts further missions in our of substantial scientific interest. Effectively, solar system and beyond, with Neptune and the planetary research community has been Uranus acting as the last stops on a Grand giving the ice giants the cold shoulder. Tour of the outer solar system. But recently, exoplanet data began In the 31 years since Voyager 2 left the revealing the abundance of icy exoplanets Neptune system in 1989 and began its in our galaxy “and new questions about WWW.ASTRONOMY.COM 41 With a rotation axis tilted more than 90 degrees compared to its orbital plane, Neptune likewise has a highly tilted rotation axis and tilted magnetic axis.
    [Show full text]
  • Neptune 1 Neptunian Day = 16.1 Earth Hours
    1 Neptunian day = 16.1 Earth hours When the Voyager 2 spacecraft flew past Neptune 1 Neptunian year = 165 Earth years Neptune in 1989, two dark spots were visible in Neptune's atmosphere. The Neptune is the outermost smaller one (left, below center) was a ice giant planet in our solar system. storm, but the Great Dark Spot (far left) Small amounts of methane in its was just a gap in Neptune's methane atmosphere lend it a deep blue colour. cloud deck. The Great Dark Spot had Neptune was discovered because its vanished by the time the Hubble Space gravity slightly alters the orbit of Uranus. Telescope viewed Neptune in 1994, but Observing Uranus’ orbit after its a new dark spot had appeared in the discovery enabled astronomers to opposite hemisphere. predict the existence and location of a previously unknown planet. That planet, Neptune, was discovered on September 23, 1846. Neptune and Triton (seen as crescents above) are shown below with their correct sizes and separation relative to the Sun in this scale model. Neptune's largest moon, Triton, is shown above. Triton orbits Neptune opposite to the direction Neptune spins. The tidal bulges Triton raises on Neptune pull backwards on Triton, pulling Triton a tiny distance closer to Neptune with every orbit. Eventually Triton will either crash into Neptune or be torn apart and form bright rings around Neptune like those around Saturn. Above, cirrus-type clouds on Neptune cast All images (Neptune does have a few rings already. They are much narrower and darker from NASA’s shadows on deeper cloud layers.
    [Show full text]
  • Our Solar System Lithograph
    National Aeronautics and and Space Space Administration Administration OURSOLARSYSTEM 2013 www.nasa.gov Inside Educational Product Our Solar System Earth Meteors and Meteorites Saturn Pluto and Charon Educators Grades K–12+ LS-2013-07-003-HQ Our Star — The Sun Earth’s Moon Moons of the Solar System Moons of Saturn Comets JPL 400-1489 07/13 Mercury Mars Jupiter Uranus Kuiper Belt and Oort Cloud Venus Asteroids Galilean Moons of Jupiter Neptune What Is a Planet? NASA EDUCATIONAL RESOURCES Educator Resource Center Network (ERCN) The EarthSpace portal (www.lpi.usra.edu/earthspace) is a national clearinghouse for higher information space and Earth The NASA portal (www.nasa.gov) is the gateway for information NASA’s Educator Resource Center (ERC) network helps edu- sciences, with resources for undergraduate education in plan- about content, programs, and services offered for the general cators learn about NASA educational resources and provides etary science and solar and space physics. public and the education community. NASA’s goal is to improve NASA materials. interactions for students, educators, and families with NASA Regional Educator Resource Centers offer access to NASA edu- NASA multimedia (www.nasa.gov) features International Space and its education resources. cational materials for educators. NASA has formed partnerships Station coverage, live special events, interactive educational live shows, electronic field trips, aviation and space news, and NASA’s education home page (www.nasa.gov; click on “For with universities, museums, and other educational institutions to historical NASA footage. Links to a variety of NASA resources Educators”) serves as the portal for information about edu- serve as Regional ERCs in many states.
    [Show full text]
  • Tessmann Planetarium Guide to the Solar System
    TESSMANN PLANETARIUM GUIDE TO THE SOLAR SYSTEM Solar System The Sun and Inner Planets The Sun makes up about 99.8% of the mass in the solar system. This means that almost the entire mass of the solar system is in the Sun. SUN FACTS Diameter: 864,000 miles across (109 times the Earth’s diameter) Surface Temperature: 9980° Fahrenheit (F) Core Temperature: 27,000,000° F Duration of Rotation (Solar day): 27 to 31 days Composition: Made up mostly of hydrogen (70%) and helium (28%) and other (2%) Important spacecrafts: Solar Dynamics Observatory (SDO), Solar and Heliospheric Observatory, Solar Terrestrial Relations Observatory (STEREO), and many others. Also known as: Sol The Sun 2 The Sun is the center of our solar system; all the planets in our The Sun is a Yellow Dwarf Star system orbit around the Sun near the Earth’s orbital plane. 1,200,000 Earths can fit into the Sun. The Sun outshines about 80% of the stars in the Milky Way. However, there are many stars that are much bigger and brighter than our Sun. Our Sun is a mere runt compared to the biggest of these. The Sun is a G type star and takes about 225 million years to make one orbit around the Milky Way. It is known as a yellow dwarf, although its color is actually more white than yellow. It generates energy through nuclear fusion in its core. The Sun is located in the Orion arm of the Milky Way. Sunspots are areas of strong magnetic activity and lower tem- perature on the surface of the Sun.
    [Show full text]
  • Atmospheric Mining in the Outer Solar System: Resource Capturing, Exploration, and Exploitation
    NASA/TM—2015-218096 AIAA–2013–3765 Atmospheric Mining in the Outer Solar System: Resource Capturing, Exploration, and Exploitation Bryan Palaszewski Glenn Research Center, Cleveland, Ohio April 2015 NASA STI Program . in Profile Since its founding, NASA has been dedicated • CONTRACTOR REPORT. Scientific and to the advancement of aeronautics and space science. technical findings by NASA-sponsored The NASA Scientific and Technical Information (STI) contractors and grantees. Program plays a key part in helping NASA maintain this important role. • CONFERENCE PUBLICATION. Collected papers from scientific and technical conferences, symposia, seminars, or other The NASA STI Program operates under the auspices meetings sponsored or co-sponsored by NASA. of the Agency Chief Information Officer. It collects, organizes, provides for archiving, and disseminates • SPECIAL PUBLICATION. Scientific, NASA’s STI. The NASA STI Program provides access technical, or historical information from to the NASA Technical Report Server—Registered NASA programs, projects, and missions, often (NTRS Reg) and NASA Technical Report Server— concerned with subjects having substantial Public (NTRS) thus providing one of the largest public interest. collections of aeronautical and space science STI in the world. Results are published in both non-NASA • TECHNICAL TRANSLATION. English- channels and by NASA in the NASA STI Report language translations of foreign scientific and Series, which includes the following report types: technical material pertinent to NASA’s mission. • TECHNICAL PUBLICATION. Reports of For more information about the NASA STI completed research or a major significant phase program, see the following: of research that present the results of NASA programs and include extensive data or theoretical • Access the NASA STI program home page at analysis.
    [Show full text]
  • Space Theme Circle Time Ideas
    Space Crescent Black Space: Sub-themes Week 1: Black/Crescent EVERYWHERE! Introduction to the Milky Way/Parts of the Solar System(8 Planets, 1 dwarf planet and sun) Week 2: Continue with Planets Sun and Moon Week 3: Comets/asteroids/meteors/stars Week 4: Space travel/Exploration/Astronaut Week 5: Review Cooking Week 1: Cucumber Sandwiches Week 2: Alien Playdough Week 3: Sunshine Shake Week 4: Moon Sand Week 5: Rocket Shaped Snack Cucumber Sandwich Ingredients 1 carton (8 ounces) spreadable cream cheese 2 teaspoons ranch salad dressing mix (dry one) 12 slices mini bread 2 to 3 medium cucumbers, sliced, thinly Let the children take turns mixing the cream cheese and ranch salad dressing mix. The children can also assemble their own sandwiches. They can spread the mixture themselves on their bread with a spoon and can put the cucumbers on themselves. Sunshine Shakes Ingredients and items needed: blender; 6 ounce can of unsweetened frozen orange juice concentrate, 3/4 cup of milk, 3/4 cup of water, 1 teaspoon of vanilla and 6 ice cubes. Children should help you put the items in the blender. You blend it up and yum! Moon Sand Materials Needed: 6 cups play sand (you can purchased colored play sand as well!); 3 cups cornstarch; 1 1/2 cups of cold water. -Have the children help scoop the corn starch and water into the table and mix until smooth. -Add sand gradually. This is very pliable sand and fun! -Be sure to store in an airtight container when not in use. If it dries, ad a few tablespoons of water and mix it in.
    [Show full text]
  • Aerospace Micro-Lesson
    AIAA AEROSPACE M ICRO-LESSON Easily digestible Aerospace Principles revealed for K-12 Students and Educators. These lessons will be sent on a bi-weekly basis and allow grade-level focused learning. - AIAA STEM K-12 Committee. THE VOYAGER MISSIONS Forty years ago this month, on August 20, 1977, Voyager 2 was launched from Cape Canaveral in Florida. Its companion spacecraft, Voyager 1, launched two weeks later, on September 5. Voyager 1 flew past Jupiter on March 5, 1979 and Saturn on November 12, 1980. The slower-moving Voyager 2 reached Jupiter on July 9, 1979 and Saturn on August 25, 1981. Taking advantage of a very unusual alignment of the outer planets, Voyager 2 went on to Uranus, reaching it on January 24, 1986, and Neptune, which it flew past on August 25, 1989. (The dates given are those of the spacecraft’s closest approaches to the planets.) The two spacecraft are now leaving the Solar System and starting to fly into interstellar space. Next Generation Science Standards (NGSS): Discipline: Earth and Space Sciences. Crosscutting Concept: Scale, proportion, and quantity. Science & Engineering Practice: Obtaining, evaluating, and communicating information. GRADES K-2 NGSS: Earth’s Place in the Universe: Use observations of the sun, moon, and stars to describe patterns that can be predicted. In 1977, the United States launched two spacecraft to the outer planets of the Solar System. Their primary mission was to explore the planets Jupiter and Saturn. They discovered many new facts about the planets such as how complicated the rings of Saturn are and that Jupiter’s moon Io has active volcanoes (which makes it very different from our own moon).
    [Show full text]
  • THE ODYSSEY of VOYAGER and MAC%L.LAN Douglas G. Griffith
    THE ODYSSEY OF VOYAGER AND MAC%l.LAN Douglas G. Griffith Magellan Project Manager, Jet Propulsion Laboratory California In..titute of Technology, U.S.A. The Voyager and Magellan spacecraft have provided an unprecedented set of ~iscove ries in space during the past 15 years. Voyager had its origins in the “Outer Planets Grand Tour” to the outer solar system but was scaled down to a mission to Jupiter and Saturn with an option to proceed on to Uranus and Neptune. These were indeed accomplished with two Voyager spacecraft launched in the summer of 1977 leading to the final planetary encounter at Neptune in 1989. Magellan had its origins in a more comprehensive program to Venus and ironically was in a planning and development stage during most of the Voyager flight odyssey to the outer planets between 1977 and the Magellan launch in May of 1989. The Voyager mission was a once-in-a-lifetime opportunity since the mission needed planetary gravity assists to acquire sufficient velocity to reach each succeeding planet. The required outer planetary alignment occurs once every 176 years, whereas the Magellan mission to Venus could be launched in any year. VOYAGER’s first stop was at Jupiter with Voyager 1 and 2 arriving on March 5th and July 9th, 1979 respectively. Jupiter, the giant of all the planets, is so large that 1300 Earths could fit within it. Jupiter is mostly made of hydrogen and helium in liquid or gaseous states. Huge storms rage in its atmosphere. One, the Great Red Spot, is a storm about three times the size of Earth that has been viewed from Earth for over 350 years.
    [Show full text]
  • Exploration of the Ice Giants AURA Washington, DC, USA 16Th Appleton Space Conference
    Heidi B. Hammel Exploration of the Ice Giants AURA Washington, DC, USA 16th Appleton Space Conference Terrestrial planets Mercury, Venus, Earth, Mars Gas Giant planets Jupiter & Saturn Uranus Neptune Ice Giant planets What are ICE GIANTS? Number of Exoplanets by Radius (as of 2/11/20) 1400 1200 1000 800 600 400 Number of Exoplanets of Number 200 0 R ≤ 1.25 R 1.25 - 2 R 2 - 6 R 6 - 15 R 15 R ≤ R R ≤ 1.25 R_Earth 1.25 < R ≤ 2 R_Earth 2 < R ≤ 6 R_Earth 6 < R ≤ 15 R_Earth 15 R_Earth < R ⨁ Exoplanet ⨁size (where R ⨁= Radius of Earth) ⨁ ⨁ ⨁ Voyager 2 Launched 1977 Uranus flyby 1986 Neptune flyby 1989 NASA / JPL-Caltech / Björn Jónsson Sun from Neptune Sun from Uranus ICE GIANT ATMOSPHERES Voyager Uranus in 1986 Smith et al. 1986 Voyager Uranus in 1986 3.8" Smith et al. 1986 adaptive optics power of adaptive optics keck 10-m mauna kea 9 july 2004 Hammel & de Pater H (1.6 µm) adaptive optics OFFON 2007 equinox 2028 1986 Voyager flyby solstice 2049 Keck in 2012 - best maps of Uranus EVER Larry Sromovsky, Pat Fry, Heidi Hammel, Imke de Pater: Keck Observatory, H band (1.6 microns), July 2012 Keck in 2012 - best maps of Uranus EVER equatorial waves moist convective storms “popcorn” clouds Voyager Neptune in 1989 2.3" Smith et al. 1989 Neptune with Hubble – remarkably variable atmosphere Hubble’s first look at Neptune after Voyager in 1994 - the Great Dark Spot gone! A NEW Great Dark Spot seen in northern hemisphere Neptune anniversary in 2011: in the same location in the sky where it was discovered nearly 165 years earlier (and no Great Dark Spot)
    [Show full text]
  • Our Solar System
    German Aerospace Center Institute of Planetary Research OUR SOLAR SYSTEM A Short Introduction to the Bodies of our Solar System and their Exploration Prepared by Susanne Pieth and Ulrich Köhler Regional Planetary Image Facility Director: Prof. Dr. Ralf Jaumann Data Manager: Susanne Pieth 2013, 3rd and enhanced edition CONTENT 3 Preface 5 Exploring the Solar System with space probes 10 Comparative planetology in the Solar System 14 Sun 17 Mercury 21 Venus 25 Earth-Moon system 37 Mars 42 Asteroids 48 Jupiter 53 Saturn 60 Uranus 64 Neptune 68 Comets 72 Dwarf planets 76 Kuiper belt 79 Planetary evolution and life Addendum 84 Overview about the missions in the Solar System 97 How can I order image data? These texts were written with the help of Dr. Manfred Gaida, Prof. Dr. Alan Harris, Ernst Hauber, Dr. Jörn Helbert, Prof. Dr. Harald Hiesinger, Dr. Hauke Hußmann, Prof. Dr. Ralf Jaumann, Dr. Ekkehard Kührt, Dr. René Laufer, Dr. Stefano Mottola, Prof. Dr. Jürgen Oberst, Dr. Frank Sohl, Prof. Dr. Tilman Spohn, Dr. Katrin Stephan, Dr. Daniela Tirsch, and Dr. Roland Wagner. Preface PREfacE A journey through the Solar System ‘Blue Planet‘ is fragile and needs to be protected, and that it is the best of all imaginable spaceships. The year 2009 was proclaimed the International Year of Astrono- my to commemorate a defining moment in history. It was exactly In fact, however, every riddle that is solved raises fresh questions. 400 years before that Galileo Galilei had turned his telescope to How did life originate on Earth? Did it come from another celestial the sky for the first time – and what he discovered was truly revo- body, and would life on Earth be possible at all without the Moon‘s lutionary.
    [Show full text]
  • Neptune by Cynthia Sherwood
    Name: _______________________ Neptune by Cynthia Sherwood Neptune is the eighth planet from the sun and the one that’s the farthest away. (Pluto is even farther, but it doesn’t count since most astronomers no longer consider it a planet.) Neptune is a cold, dark place that’s the smallest of the gas giants. It was named after the Roman god of water and the sea. Neptune is a ball of gas and ice, with a rocky core. Thick bright blue clouds cover its surface. They’re made up mainly of frozen methane gas. Like the other “gas giant” planets, winds that blow Neptune’s clouds around are very strong. Scientists say winds reach speeds of up to 700 miles an hour (about 1,120 kilometers per hour). Neptune isn’t quite as cold as Uranus, but its largest moon, Triton, is even colder. Triton has a surface temperature of minus 390 degrees Fahrenheit (minus 234 Celsius), which is the coldest known temperature in the solar system. Scientists think that Triton used to be a large comet that became trapped by Neptune’s gravity. Because it’s so far away, Neptune only has had one visit from How it Was a spacecraft. NASA’s Voyager 2 flew by Neptune in 1989. Named... Voyager discovered a huge storm on Neptune that it called the “Great Dark Spot,” similar to Jupiter’s “Great Red Spot.” But later pictures from the Hubble Telescope found that the Great Dark Spot had vanished. Luckily for us, Neptune and Earth don’t have much in Neptune was named for the common.
    [Show full text]
  • Ice Giant Systems: Scientific Potential of Missions to Uranus and Neptune
    ICE GIANT SYSTEM EXPLORATION Ice Giant System Exploration WHITE PAPER RESPONSE TO ESA CALL FOR VOYAGE 2050 SCIENCE THEMES Executive Summary Uranus and Neptune, and their diverse satellite and ring systems, represent the least explored environments of our Solar System, and yet may provide the archetype for the most common outcome of planetary formation throughout our galaxy. Ice Giants are the last remaining class of planet in our system to have a dedicated orbital mission. This white paper describes how such a mission could explore their origins, ice-rich interiors, dynamic atmospheres, unique magnetospheres, and myriad icy satellites, to address questions at the very heart of modern planetary science. These two worlds are superb examples of how planets with shared origins can exhibit remarkably different evolutionary paths: Neptune as the archetype for Ice Giants, Uranus as the oddity. Exploring Uranus’ natural satellites and Neptune’s captured moon Triton could reveal how Ocean Worlds form and remain active, redefining the extent of the habitable zone in our Solar System. For these reasons and more, we propose that an Ice Giant System mission shoulD become a strategic cornerstone spacecraft for ESA in the Voyage 2050 programme. to be extended mission targets. Uranus and Neptune 1. Why Explore Ice Giant Systems? .............................. 2 have therefore never haD a DeDicateD mission, despite 2. Science Themes for Ice Giant Exploration ................ 4 the rich and diverse systems displayed in Figure 1. A 3. Ice Giant Science in Context ................................... 16 return to the Ice Giants with an orbiter is the next logical step in humankind’s exploration of our Solar System.
    [Show full text]