New Data, New Ideas, and Lively Debate About Mercury
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Mission to Jupiter
This book attempts to convey the creativity, Project A History of the Galileo Jupiter: To Mission The Galileo mission to Jupiter explored leadership, and vision that were necessary for the an exciting new frontier, had a major impact mission’s success. It is a book about dedicated people on planetary science, and provided invaluable and their scientific and engineering achievements. lessons for the design of spacecraft. This The Galileo mission faced many significant problems. mission amassed so many scientific firsts and Some of the most brilliant accomplishments and key discoveries that it can truly be called one of “work-arounds” of the Galileo staff occurred the most impressive feats of exploration of the precisely when these challenges arose. Throughout 20th century. In the words of John Casani, the the mission, engineers and scientists found ways to original project manager of the mission, “Galileo keep the spacecraft operational from a distance of was a way of demonstrating . just what U.S. nearly half a billion miles, enabling one of the most technology was capable of doing.” An engineer impressive voyages of scientific discovery. on the Galileo team expressed more personal * * * * * sentiments when she said, “I had never been a Michael Meltzer is an environmental part of something with such great scope . To scientist who has been writing about science know that the whole world was watching and and technology for nearly 30 years. His books hoping with us that this would work. We were and articles have investigated topics that include doing something for all mankind.” designing solar houses, preventing pollution in When Galileo lifted off from Kennedy electroplating shops, catching salmon with sonar and Space Center on 18 October 1989, it began an radar, and developing a sensor for examining Space interplanetary voyage that took it to Venus, to Michael Meltzer Michael Shuttle engines. -
Copyrighted Material
Index Abulfeda crater chain (Moon), 97 Aphrodite Terra (Venus), 142, 143, 144, 145, 146 Acheron Fossae (Mars), 165 Apohele asteroids, 353–354 Achilles asteroids, 351 Apollinaris Patera (Mars), 168 achondrite meteorites, 360 Apollo asteroids, 346, 353, 354, 361, 371 Acidalia Planitia (Mars), 164 Apollo program, 86, 96, 97, 101, 102, 108–109, 110, 361 Adams, John Couch, 298 Apollo 8, 96 Adonis, 371 Apollo 11, 94, 110 Adrastea, 238, 241 Apollo 12, 96, 110 Aegaeon, 263 Apollo 14, 93, 110 Africa, 63, 73, 143 Apollo 15, 100, 103, 104, 110 Akatsuki spacecraft (see Venus Climate Orbiter) Apollo 16, 59, 96, 102, 103, 110 Akna Montes (Venus), 142 Apollo 17, 95, 99, 100, 102, 103, 110 Alabama, 62 Apollodorus crater (Mercury), 127 Alba Patera (Mars), 167 Apollo Lunar Surface Experiments Package (ALSEP), 110 Aldrin, Edwin (Buzz), 94 Apophis, 354, 355 Alexandria, 69 Appalachian mountains (Earth), 74, 270 Alfvén, Hannes, 35 Aqua, 56 Alfvén waves, 35–36, 43, 49 Arabia Terra (Mars), 177, 191, 200 Algeria, 358 arachnoids (see Venus) ALH 84001, 201, 204–205 Archimedes crater (Moon), 93, 106 Allan Hills, 109, 201 Arctic, 62, 67, 84, 186, 229 Allende meteorite, 359, 360 Arden Corona (Miranda), 291 Allen Telescope Array, 409 Arecibo Observatory, 114, 144, 341, 379, 380, 408, 409 Alpha Regio (Venus), 144, 148, 149 Ares Vallis (Mars), 179, 180, 199 Alphonsus crater (Moon), 99, 102 Argentina, 408 Alps (Moon), 93 Argyre Basin (Mars), 161, 162, 163, 166, 186 Amalthea, 236–237, 238, 239, 241 Ariadaeus Rille (Moon), 100, 102 Amazonis Planitia (Mars), 161 COPYRIGHTED -
Glossary Glossary
Glossary Glossary Albedo A measure of an object’s reflectivity. A pure white reflecting surface has an albedo of 1.0 (100%). A pitch-black, nonreflecting surface has an albedo of 0.0. The Moon is a fairly dark object with a combined albedo of 0.07 (reflecting 7% of the sunlight that falls upon it). The albedo range of the lunar maria is between 0.05 and 0.08. The brighter highlands have an albedo range from 0.09 to 0.15. Anorthosite Rocks rich in the mineral feldspar, making up much of the Moon’s bright highland regions. Aperture The diameter of a telescope’s objective lens or primary mirror. Apogee The point in the Moon’s orbit where it is furthest from the Earth. At apogee, the Moon can reach a maximum distance of 406,700 km from the Earth. Apollo The manned lunar program of the United States. Between July 1969 and December 1972, six Apollo missions landed on the Moon, allowing a total of 12 astronauts to explore its surface. Asteroid A minor planet. A large solid body of rock in orbit around the Sun. Banded crater A crater that displays dusky linear tracts on its inner walls and/or floor. 250 Basalt A dark, fine-grained volcanic rock, low in silicon, with a low viscosity. Basaltic material fills many of the Moon’s major basins, especially on the near side. Glossary Basin A very large circular impact structure (usually comprising multiple concentric rings) that usually displays some degree of flooding with lava. The largest and most conspicuous lava- flooded basins on the Moon are found on the near side, and most are filled to their outer edges with mare basalts. -
Carnegie Institution of Washington Department of Terrestrial Magnetism Washington, DC 20015-1305
43 Carnegie Institution of Washington Department of Terrestrial Magnetism Washington, DC 20015-1305 This report covers astronomical research carried out during protostellar outflows have this much momentum out to rela- the period July 1, 1994 – June 30, 1995. Astronomical tively large distances. Planetary nebulae do not, but with studies at the Department of Terrestrial Magnetism ~DTM! their characteristic high post-shock temperatures, collapse of the Carnegie Institution of Washington encompass again occurs. Hence all three outflows appear to be able to observational and theoretical fields of solar system and trigger the collapse of molecular clouds to form stars. planet formation and evolution, stars and star formation, Foster and Boss are continuing this work and examining galaxy kinematics and evolution, and various areas where the possibility of introducing 26Al into the early solar system these fields intersect. in a heterogeneous manner. Some meteoritical inclusions ~chondrules! show no evidence for live 26Al at the time of their formation. So either the chondrules formed after the 1. PERSONNEL aluminium had decayed away, or the solar nebula was not Staff Members: Sean C. Solomon ~Director!, Conel M. O’D. Alexander, Alan P. Boss, John A. Graham, Vera C. Rubin, uniformly populated with the isotope. Foster & Boss are ex- Franc¸ois Schweizer, George W. Wetherill ploring the injection of shock wave particles into the collaps- Postdoctoral Fellows: Harold M. Butner, John E. Chambers, ing solar system. Preliminary results are that ;40% of the Prudence N. Foster, Munir Humayun, Stacy S. McGaugh, incident shock particles are swallowed by the collapsing Bryan W. Miller, Elizabeth A. Myhill, David L. -
Lecture 9—Is the Earth Rare?
41st Saas-Fee Course From Planets to Life 3-9 April 2011 Lecture 9—Is the Earth Rare? List of Rare Earth arguments/ Nitrogen abundance/ Frequency of large impacts/ Chaotic obliquity fluctuations J. F. Kasting The Gaia hypothesis First presented in the 1970s by James Lovelock 1979 1988 • Life itself is what stabilizes planetary environments • Corollary: A planet might need to be inhabited in order to remain habitable The Medea and Rare Earth hypotheses Peter Ward 2009 2000 Medea hypothesis: Life is harmful to the Earth! Rare Earth hypothesis: Complex life (animals, including humans) is rare in the universe Additional support for the Rare Earth hypothesis • Lenton and Watson think that complex life (animal life) is rare because it requires a series of unlikely evolutionary events – the origin of life – the origin of the genetic code – the development of oxygenic photosynthesis) – the origin of eukaryotes – the origin of sexuality 2011 Rare Earth/Gaia arguments 1. Plate tectonics is rare --We have dealt with this already. Plate tectonics is not necessarily rare, but it requires liquid water. Thus, a planet needs to be within the habitable zone. 2. Other planets may lack magnetic fields and may therefore have harmful radiation environments and be subject to loss of atmosphere – We have talked about this one also. Venus has retained its atmosphere. The atmosphere itself provides protection against cosmic rays 3. The animal habitable zone (AHZ) is smaller than the habitable zone (HZ) o – AHZ definition: Ts = 0-50 C o – HZ definition: Ts = 0-100 C. But this is wrong! For a 1-bar atmosphere like Earth, o water loss begins when Ts reaches 60 C. -
Chapter 9: the Origin and Evolution of the Moon and Planets
Chapter 9 THE ORIGIN AND EVOLUTION OF THE MOON AND PLANETS 9.1 In the Beginning The age of the universe, as it is perceived at present, is perhaps as old as 20 aeons so that the formation of the solar system at about 4.5 aeons is a comparatively youthful event in this stupendous extent of time [I]. Thevisible portion of the universe consists principally of about 10" galaxies, which show local marked irregularities in distribution (e.g., Virgo cluster). The expansion rate (Hubble Constant) has values currently estimated to lie between 50 and 75 km/sec/MPC [2]. The reciprocal of the constant gives ages ranging between 13 and 20 aeons but there is uncertainty due to the local perturbing effects of the Virgo cluster of galaxies on our measurement of the Hubble parameter [I]. The age of the solar system (4.56 aeons), the ages of old star clusters (>10" years) and the production rates of elements all suggest ages for the galaxy and the observable universe well in excess of 10" years (10 aeons). The origin of the presently observable universe is usually ascribed, in current cosmologies, to a "big bang," and the 3OK background radiation is often accepted as proof of the correctness of the hypothesis. Nevertheless, there are some discrepancies. The observed ratio of hydrogen to helium which should be about 0.25 in a "big-bang" scenario may be too high. The distribution of galaxies shows much clumping, which would indicate an initial chaotic state [3], and there are variations in the spectrum of the 3OK radiation which are not predicted by the theory. -
Triton: Topography and Geology of a Probable Ocean World with Comparison to Pluto and Charon
remote sensing Article Triton: Topography and Geology of a Probable Ocean World with Comparison to Pluto and Charon Paul M. Schenk 1,* , Chloe B. Beddingfield 2,3, Tanguy Bertrand 3, Carver Bierson 4 , Ross Beyer 2,3, Veronica J. Bray 5, Dale Cruikshank 3 , William M. Grundy 6, Candice Hansen 7, Jason Hofgartner 8 , Emily Martin 9, William B. McKinnon 10, Jeffrey M. Moore 3, Stuart Robbins 11 , Kirby D. Runyon 12 , Kelsi N. Singer 11 , John Spencer 11, S. Alan Stern 11 and Ted Stryk 13 1 Lunar and Planetary Institute, Houston, TX 77058, USA 2 SETI Institute, Palo Alto, CA 94020, USA; chloe.b.beddingfi[email protected] (C.B.B.); [email protected] (R.B.) 3 NASA Ames Research Center, Moffett Field, CA 94035, USA; [email protected] (T.B.); [email protected] (D.C.); [email protected] (J.M.M.) 4 School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85202, USA; [email protected] 5 Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85641, USA; [email protected] 6 Lowell Observatory, Flagstaff, AZ 86001, USA; [email protected] 7 Planetary Science Institute, Tucson, AZ 85704, USA; [email protected] 8 Jet Propulsion Laboratory, Pasadena, CA 91001, USA; [email protected] 9 National Air & Space Museum, Washington, DC 20001, USA; [email protected] 10 Department of Earth and Planetary Sciences, Washington University in Saint Louis, Saint Louis, MO 63101, USA; [email protected] 11 Southwest Research Institute, Boulder, CO 80301, USA; [email protected] (S.R.); [email protected] (K.N.S.); [email protected] (J.S.); [email protected] (S.A.S.) Citation: Schenk, P.M.; Beddingfield, 12 Johns Hopkins Applied Physics Laboratory, Laurel, MD 20707, USA; [email protected] 13 C.B.; Bertrand, T.; Bierson, C.; Beyer, Humanities Division, Roane State Community College, Harriman, TN 37748, USA; [email protected] R.; Bray, V.J.; Cruikshank, D.; Grundy, * Correspondence: [email protected] W.M.; Hansen, C.; Hofgartner, J.; et al. -
Mariner to Mercury, Venus and Mars
NASA Facts National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, CA 91109 Mariner to Mercury, Venus and Mars Between 1962 and late 1973, NASA’s Jet carry a host of scientific instruments. Some of the Propulsion Laboratory designed and built 10 space- instruments, such as cameras, would need to be point- craft named Mariner to explore the inner solar system ed at the target body it was studying. Other instru- -- visiting the planets Venus, Mars and Mercury for ments were non-directional and studied phenomena the first time, and returning to Venus and Mars for such as magnetic fields and charged particles. JPL additional close observations. The final mission in the engineers proposed to make the Mariners “three-axis- series, Mariner 10, flew past Venus before going on to stabilized,” meaning that unlike other space probes encounter Mercury, after which it returned to Mercury they would not spin. for a total of three flybys. The next-to-last, Mariner Each of the Mariner projects was designed to have 9, became the first ever to orbit another planet when two spacecraft launched on separate rockets, in case it rached Mars for about a year of mapping and mea- of difficulties with the nearly untried launch vehicles. surement. Mariner 1, Mariner 3, and Mariner 8 were in fact lost The Mariners were all relatively small robotic during launch, but their backups were successful. No explorers, each launched on an Atlas rocket with Mariners were lost in later flight to their destination either an Agena or Centaur upper-stage booster, and planets or before completing their scientific missions. -
Mercury Redux
FEATURE Mercury redux In January 2008, 33 years after Mariner 10 fl ew past the solar system’s innermost planet, MESSENGER crossed Mercury’s magnetosphere. Ancient volcanoes, contractional faults, and a rich soup of exospheric ions give clues to Mercury’s structure and dynamical evolution. Th e Mercury fl yby of the MESSENGER two have not been ruled out, but for those (Mercury surface, space environment, mechanisms shorter-wavelength magnetic geochemistry and ranging) probe was the features would be expected, which were not fi rst of three braking manoeuvres for the observed during the MESSENGER fl yby1. spacecraft , in preparation for its insertion Recent libration observations that require into a polar orbit in 2011. Th e probe a partially molten core11, and the limited achieved the closest approach (201 km) of contraction of Mercury, which implies a Mercury’s surface yet, and took a variety largely molten core, favour a convective of measurements in the magnetosphere, dynamo origin for Mercury’s magnetic fi eld. exosphere and on Mercury’s surface. Some Although Mercury’s magnetosphere of the fi rst results of the MESSENGER looks like a miniature version of Earth’s, mission1–6 reveal Mercury as a planet with Mercury’s relatively weak magnetic richly interconnected dynamics, from fi eld implies that its dynamo must work the dynamo in its molten outer core, a diff erently from that of the Earth. Th e crust and surface with great lobate faults geodynamo, which gives the Earth its and relatively young volcanoes, to a strong magnetic fi eld, is thought to operate magnetosphere that interacts with the core in a magnetostrophic regime in which the dynamo and the interplanetary solar wind. -
Geologic Map of the Ganiki Planitia Quadrangle (V–14), Venus Eric B
Claremont Colleges Scholarship @ Claremont Pomona Faculty Publications and Research Pomona Faculty Scholarship 1-1-2011 Geologic Map of the Ganiki Planitia Quadrangle (V–14), Venus Eric B. Grosfils Pomona College Sylvan M. Long Elizabeth M. Venechuk Debra M. Hurwitz Joseph W. Richards See next page for additional authors Recommended Citation Grosfils, E.B., Long, S.M., Venechuk, E.M., Hurwitz, D.M., Richards, J.W., Kastl, Brian, Drury, D.E., and Hardin, Johanna, 2011, Geologic map of the Ganiki Planitia quadrangle (V-14), Venus: U.S. Geological Survey Scientific nI vestigations Map 3121. This Report is brought to you for free and open access by the Pomona Faculty Scholarship at Scholarship @ Claremont. It has been accepted for inclusion in Pomona Faculty Publications and Research by an authorized administrator of Scholarship @ Claremont. For more information, please contact [email protected]. Authors Eric B. Grosfils, Sylvan M. Long, Elizabeth M. Venechuk, Debra M. Hurwitz, Joseph W. Richards, Brian Kastl, Dorothy E. Drury, and Johanna S. Hardin This report is available at Scholarship @ Claremont: http://scholarship.claremont.edu/pomona_fac_pub/303 Prepared for the National Aeronautics and Space Administration Geologic Map of the Ganiki Planitia Quadrangle (V–14), Venus By Eric B. Grosfils, Sylvan M. Long, Elizabeth M. Venechuk, Debra M. Hurwitz, Joseph W. Richards, Brian Kastl, Dorothy E. Drury, and Johanna Hardin Pamphlet to accompany Scientific Investigations Map 3121 75° 75° V–1 V–3 V–6 50° 50° V–4 V–5 V–11 V–16 V–12 V–15 V–13 V–14 25° 25° V–23 V–28 V–24 V–27 V–25 V–26 90° 120° 150° 180° 210° 240° 270° 0° 0° V–37 V–38 V–36 V–39 V–35 V–40 –25° –25° V–49 V–50 V–48 V–51 V–47 V–52 V–58 V–59 –50° –50° V–57 V–60 2011 V–62 –75° –75° U.S. -
Dynamical Models of Terrestrial Planet Formation
Dynamical Models of Terrestrial Planet Formation Jonathan I. Lunine, LPL, The University of Arizona, Tucson AZ USA, 85721. [email protected] David P. O’Brien, Planetary Science Institute, Tucson AZ USA 85719 Sean N. Raymond, CASA, University of Colorado, Boulder CO USA 80302 Alessandro Morbidelli, Obs. de la Coteˆ d’Azur, Nice, F-06304 France Thomas Quinn, Department of Astronomy, University of Washington, Seattle USA 98195 Amara L. Graps, SWRI, Boulder CO USA 80302 Revision submitted to Advanced Science Letters May 23, 2009 Abstract We review the problem of the formation of terrestrial planets, with particular emphasis on the interaction of dynamical and geochemical models. The lifetime of gas around stars in the process of formation is limited to a few million years based on astronomical observations, while isotopic dating of meteorites and the Earth-Moon system suggest that perhaps 50-100 million years were required for the assembly of the Earth. Therefore, much of the growth of the terrestrial planets in our own system is presumed to have taken place under largely gas-free conditions, and the physics of terrestrial planet formation is dominated by gravitational interactions and collisions. The ear- liest phase of terrestrial-planet formation involve the growth of km-sized or larger planetesimals from dust grains, followed by the accumulations of these planetesimals into ∼100 lunar- to Mars- mass bodies that are initially gravitationally isolated from one-another in a swarm of smaller plan- etesimals, but eventually grow to the point of significantly perturbing one-another. The mutual perturbations between the embryos, combined with gravitational stirring by Jupiter, lead to orbital crossings and collisions that drive the growth to Earth-sized planets on a timescale of 107 − 108 years. -
The Iron Planet Sex and Skin Color
PERIODICALS Yet, this is the key to the lesson, Kass says. necessary condition for national self- "God's dispersion of the nations is the PO- awareness and the possibility of a politics litical analog to the creation of woman: in- that will. hearken to the voice of what is stituting otherness and opposition, it is the eternal, true, and good." SCIENCE & TECHNOLOGY ''Mercu~'~Heart of Iron" by Clark R. Chapman, in Asfrononzy The Iron Planet (Nov. 19881, 1027 N. 7th St., Milwaukee, Wisc. 53233. More than a decade after America's un- plays a vita1 role in the two leading theo- manned Mariner 10 flew near the planet ries of the origins of the solar system. Ac- Mercury during 1974-75, scientists have fi- cording to one theory, formulated by cos- nally digested all of the data from the mochemist John Lewis during the 1970~~ flight. And they are starting to ask some the solar system was created in a more or big questions, reports Chapman, of Tuc- less orderly fashion. Lewis believes that son's Planetary Science Institute. the planets formed out of gases that cooled Located about midway between the and condensed. At some point, billions of Earth and the Sun, Mercury is a "truly bi- years ago, the sun flared up briefly, blast- zarre" planet. Its rock cmst is unusually ing away many gases. According to Lewis's thin; a "metallic iron core" accounts for theory, there should not be any sulfur, or 70 percent of the planet's weight. anything like it, on Mercury. The most surprising discovery made by A more recent theory, propounded by Mariner 10 was that the tiny planet has a George Wetherill of the Carnegie Institu- magnetic field, like Earth's but much tion, is that the solar system emerged from weaker.