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A Wunda-Full World? Carbon Dioxide Ice Deposits on Umbriel and Other Uranian Moons
Icarus 290 (2017) 1–13 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus A Wunda-full world? Carbon dioxide ice deposits on Umbriel and other Uranian moons ∗ Michael M. Sori , Jonathan Bapst, Ali M. Bramson, Shane Byrne, Margaret E. Landis Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA a r t i c l e i n f o a b s t r a c t Article history: Carbon dioxide has been detected on the trailing hemispheres of several Uranian satellites, but the exact Received 22 June 2016 nature and distribution of the molecules remain unknown. One such satellite, Umbriel, has a prominent Revised 28 January 2017 high albedo annulus-shaped feature within the 131-km-diameter impact crater Wunda. We hypothesize Accepted 28 February 2017 that this feature is a solid deposit of CO ice. We combine thermal and ballistic transport modeling to Available online 2 March 2017 2 study the evolution of CO 2 molecules on the surface of Umbriel, a high-obliquity ( ∼98 °) body. Consid- ering processes such as sublimation and Jeans escape, we find that CO 2 ice migrates to low latitudes on geologically short (100s–1000 s of years) timescales. Crater morphology and location create a local cold trap inside Wunda, and the slopes of crater walls and a central peak explain the deposit’s annular shape. The high albedo and thermal inertia of CO 2 ice relative to regolith allows deposits 15-m-thick or greater to be stable over the age of the solar system. -
Exomoon Habitability Constrained by Illumination and Tidal Heating
submitted to Astrobiology: April 6, 2012 accepted by Astrobiology: September 8, 2012 published in Astrobiology: January 24, 2013 this updated draft: October 30, 2013 doi:10.1089/ast.2012.0859 Exomoon habitability constrained by illumination and tidal heating René HellerI , Rory BarnesII,III I Leibniz-Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany, [email protected] II Astronomy Department, University of Washington, Box 951580, Seattle, WA 98195, [email protected] III NASA Astrobiology Institute – Virtual Planetary Laboratory Lead Team, USA Abstract The detection of moons orbiting extrasolar planets (“exomoons”) has now become feasible. Once they are discovered in the circumstellar habitable zone, questions about their habitability will emerge. Exomoons are likely to be tidally locked to their planet and hence experience days much shorter than their orbital period around the star and have seasons, all of which works in favor of habitability. These satellites can receive more illumination per area than their host planets, as the planet reflects stellar light and emits thermal photons. On the contrary, eclipses can significantly alter local climates on exomoons by reducing stellar illumination. In addition to radiative heating, tidal heating can be very large on exomoons, possibly even large enough for sterilization. We identify combinations of physical and orbital parameters for which radiative and tidal heating are strong enough to trigger a runaway greenhouse. By analogy with the circumstellar habitable zone, these constraints define a circumplanetary “habitable edge”. We apply our model to hypothetical moons around the recently discovered exoplanet Kepler-22b and the giant planet candidate KOI211.01 and describe, for the first time, the orbits of habitable exomoons. -
L RES~ARCH Coljncll ·
NA~IOf\i'At ACADEMIES OF SCIENCE AND ENGiNEERING 7 ·.· ·.·. : NATIONAL RES~ARCH ColJNCll · of the UNITED STATES OF AMERICA UNITED• STATES NATIONAL COMMITTEEI . International Union of Radio Sden<:e Nationa.1 Radio Science Meeting 13-15 January 1982 · f l··.. ·· Sponsored by USNC/URSI in cooperation with r Institute of Electrical and Electronics Engineers University of· Colorado Boulder, Colorado U.S.A. ~· 1' National Radio Science Meeting 13-15 January 19 82 Condensed Technical Program TUESDAY, 12 JANUARY 0900 CCIR U.S. Study Group 5 OT 8-8 CCIR U.S. Study ,Gr.oup 6 Radio Building 2000-2400 USNC/URSI Meeting Broker Inn WEDNESDAY, 13 JANUARY 0900-1200 A-1 Time Domai~ 1-ieasurements CRl-42 B-1 Scattering CR2-28 B-2 Electromagnetic Theory CR2-28 C-1 Topics in Information Theory CR0-30 F-1 Propagation Theory and Models CR2-26 J-1 Millimeter-Wave Astronomy UMC Ballroom 1330-1700 A-2 Microwave/Millimeter Wave Measurements CRl-42 B-3 Antenna Theory and Practice CR2-28 B-4 Inverse Scattering CR2-6 C-2 Digital HF: Equaltz ation and Reiated CR0-30 Techniques E-1 EM Noise in the Sea CRl-40 F-2 Ground-Based Remote Sensing CR2-26 H-1 VLF-ELF Wave Injection Into the CRl-46 Magnetosphere J-2 Very Long Baseline Interferometry UMC 157 1700 Commission A Business Meeting CRl-42 Commission C Business Meeting CR0-30 Commission E Business Meeting CRl-40 Commission F Business Meeting CR2-26 Commission H Business Meeting CRl-46 1800-2000 Reception Engineering Center 2000-2200 IEEE Wave Propagation Standards Committee CRl-46 TH.URSDAY, 14 JANUARY 0830-1200 A-3 -
Planetary Nomenclature: an Overview and Update
3rd Planetary Data Workshop 2017 (LPI Contrib. No. 1986) 7119.pdf PLANETARY NOMENCLATURE: AN OVERVIEW AND UPDATE. T. Gaither1, R. K. Hayward1, J. Blue1, L. Gaddis1, R. Schulz2, K. Aksnes3, G. Burba4, G. Consolmagno5, R. M. C. Lopes6, P. Masson7, W. Sheehan8, B.A. Smith9, G. Williams10, C. Wood11, 1USGS Astrogeology Science Center, Flagstaff, Ar- izona ([email protected]); 2ESA Scientific Support Office, Noordwijk, The Netherlands; 3Institute for Theoretical Astrophysics, Oslo, Norway; 4Vernadsky Institute, Moscow, Russia; 5Specola Vaticana, Vati- can City State; 6Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California; 7Uni- versite de Paris-Sud, Orsay, France; 8Lowell Observatory, Flagstaff, Arizona; 9Santa Fe, New Mexico; 10Minor Planet Center, Cambridge, Massachusetts; 11Planetary Science Institute, Tucson, Arizona. Introduction: The task of naming planetary Asteroids surface features, rings, and natural satellites is Ceres 113 managed by the International Astronomical Un- Dactyl 2 ion’s (IAU) Working Group for Planetary System Eros 41 Nomenclature (WGPSN). The members of the Gaspra 34 WGPSN and its task groups have worked since the Ida 25 early 1970s to provide a clear, unambiguous sys- Itokawa 17 tem of planetary nomenclature that represents cul- Lutetia 37 tures and countries from all regions of Earth. Mathilde 23 WGPSN members include Rita Schulz (chair) and Steins 24 9 other members representing countries around the Vesta 106 globe (see author list). In 2013, Blue et al. [1] pre- Jupiter sented an overview of planetary nomenclature, and Amalthea 4 in 2016 Hayward et al. [2] provided an update to Thebe 1 this overview. Given the extensive planetary ex- Io 224 ploration and research that has taken place since Europa 111 2013, it is time to update the community on the sta- Ganymede 195 tus of planetary nomenclature, the purpose and Callisto 153 rules, the process for submitting name requests, and the IAU approval process. -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
Constraints on the Habitability of Extrasolar Moons
Formation, Detection, and Characterization of Extrasolar Habitable Planets Proceedings IAU Symposium No. 293, 2012 c International Astronomical Union 2014 N. Haghighipour, ed. doi:10.1017/S1743921313012738 Constraints on the Habitability of Extrasolar Moons Ren´e Heller1 and Rory Barnes2,3 1 Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam email: [email protected] 2 University of Washington, Dept. of Astronomy, Seattle, WA 98195, USA 3 Virtual Planetary Laboratory, NASA, USA email: [email protected] Abstract. Detections of massive extrasolar moons are shown feasible with the Kepler space telescope. Kepler’s findings of about 50 exoplanets in the stellar habitable zone naturally make us wonder about the habitability of their hypothetical moons. Illumination from the planet, eclipses, tidal heating, and tidal locking distinguish remote characterization of exomoons from that of exoplanets. We show how evaluation of an exomoon’s habitability is possible based on the parameters accessible by current and near-future technology. Keywords. celestial mechanics – planets and satellites: general – astrobiology – eclipses 1. Introduction The possible discovery of inhabited exoplanets has motivated considerable efforts towards estimating planetary habitability. Effects of stellar radiation (Kasting et al. 1993; Selsis et al. 2007), planetary spin (Williams & Kasting 1997; Spiegel et al. 2009), tidal evolution (Jackson et al. 2008; Barnes et al. 2009; Heller et al. 2011), and composition (Raymond et al. 2006; Bond et al. 2010) have been studied. Meanwhile, Kepler’s high precision has opened the possibility of detecting extrasolar moons (Kipping et al. 2009; Tusnski & Valio 2011) and the first dedicated searches for moons in the Kepler data are underway (Kipping et al. -
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. -
Explore Science
SMALL SATELLITE MISSIONS FOR PLANETARY SCIENCE Carolyn R. Mercer, Ph.D. Program Executive, Small Innovative Missions for Planetary Exploration (SIMPLEx) AIAA Small Spacecraft Missions Conference August 4, 2019 Logan, Utah Apollo 15 Particles and Fields Subsatellite (PFS-1) • 35 kg spacecraft flown with Apollo 15 in 1971 • Orbited the Moon for 6 months • Science mission: • Measured the strength and direction of interplanetary and terrestrial magnetic fields • Detected variations in the lunar gravity field • Measured proton and electron flux 2 NASA SCIENCE AN INTEGRATED PROGRAM Helio- Earth physics Science Planetary Astrophysics Science Joint Agency Satellite Division 4 Small Spacecraft for Planetary Science Astrobiology Science and Technology Instrument Development (ASTID) 2008 • O/OREOS (2010 launch) Small Innovative Missions for Planetary Exploration (SIMPLEx-1) 2014 • LunaH-Map, Q-PACE Directed and Partnered Secondary Payloads • MarCO (2018 launch) • LICIA Cube (2021) – potential ASI contribution Planetary Science Deep Space SmallSat Studies (PSDS3) 2017 • 19 Studies – Presented March 2018 at LPSC Small Innovative Missions for Planetary Exploration (SIMPLEx-2) 2018 • Janus, Escapade, Lunar Trailblazer • Next proposals due no earlier than June 2020 5 Planetary Science Deep Space SmallSat Studies Solicitation requested: • Concepts for planetary science missions • 180 kg total spacecraft mass limit • $100M cost cap • No constraints on rides, infrastructure, etc. Solicitation sought answers to: • Can deep space missions be credibly done -
Why Sex? Now Shown That in Water Fleas, Recombination Does Lead to Fewer Deleterious Mutations
PERSPECTIVES EVOLUTION It is assumed that most organisms have sex because the resulting genetic recombination allows Darwinian selection to work better. It is Why Sex? now shown that in water fleas, recombination does lead to fewer deleterious mutations. Rasmus Nielsen hy sex? This has been one of the most sexual reproduction. Additionally, fundamental questions in evolution- the best explanations regarding dele- Wary biology. In many species, males terious mutations rely on strong do not provide parental care to the offspring. assumptions regarding the distribu- Clearly, the rate of reproduction could be tion of selective effects (3), and there increased if all individuals were born as females may be other factors favoring and reproduced asexually without the need to sex, such as increased resistance to mate with a male (parthenogenetic reproduc- pathogens (4). An observed genomic tion). Parthenogenetically reproducing females correlation between the rate of recom- arising in a sexual population should have a bination and variability within species twofold fitness advantage because they, on aver- (5) suggests that there is an interaction age, leave twice as many gene copies in the next between selection and recombination, generation. Nonetheless, sexual reproduction is but a direct difference between sexual ubiquitous in higher organisms. Why do all these and asexual populations has been hard species bother to have males, if males are associ- to establish. ated with a reduction in fitness? The main solu- However, the new study by Paland tion that population geneticists have proposed to and Lynch (1) provides direct empir- this conundrum is that sexual reproduction ical support for an excess accumula- allows genetic recombination, and that genetic tion of mutations in asexually repro- recombination is advantageous because it allows ducing populations compared to natural Darwinian selection to work more effi- sexual populations. -
Abstracts of the 50Th DDA Meeting (Boulder, CO)
Abstracts of the 50th DDA Meeting (Boulder, CO) American Astronomical Society June, 2019 100 — Dynamics on Asteroids break-up event around a Lagrange point. 100.01 — Simulations of a Synthetic Eurybates 100.02 — High-Fidelity Testing of Binary Asteroid Collisional Family Formation with Applications to 1999 KW4 Timothy Holt1; David Nesvorny2; Jonathan Horner1; Alex B. Davis1; Daniel Scheeres1 Rachel King1; Brad Carter1; Leigh Brookshaw1 1 Aerospace Engineering Sciences, University of Colorado Boulder 1 Centre for Astrophysics, University of Southern Queensland (Boulder, Colorado, United States) (Longmont, Colorado, United States) 2 Southwest Research Institute (Boulder, Connecticut, United The commonly accepted formation process for asym- States) metric binary asteroids is the spin up and eventual fission of rubble pile asteroids as proposed by Walsh, Of the six recognized collisional families in the Jo- Richardson and Michel (Walsh et al., Nature 2008) vian Trojan swarms, the Eurybates family is the and Scheeres (Scheeres, Icarus 2007). In this theory largest, with over 200 recognized members. Located a rubble pile asteroid is spun up by YORP until it around the Jovian L4 Lagrange point, librations of reaches a critical spin rate and experiences a mass the members make this family an interesting study shedding event forming a close, low-eccentricity in orbital dynamics. The Jovian Trojans are thought satellite. Further work by Jacobson and Scheeres to have been captured during an early period of in- used a planar, two-ellipsoid model to analyze the stability in the Solar system. The parent body of the evolutionary pathways of such a formation event family, 3548 Eurybates is one of the targets for the from the moment the bodies initially fission (Jacob- LUCY spacecraft, and our work will provide a dy- son and Scheeres, Icarus 2011). -
Cfa in the News ~ Week Ending 3 January 2010
Wolbach Library: CfA in the News ~ Week ending 3 January 2010 1. New social science research from G. Sonnert and co-researchers described, Science Letter, p40, Tuesday, January 5, 2010 2. 2009 in science and medicine, ROGER SCHLUETER, Belleville News Democrat (IL), Sunday, January 3, 2010 3. 'Science, celestial bodies have always inspired humankind', Staff Correspondent, Hindu (India), Tuesday, December 29, 2009 4. Why is Carpenter defending scientists?, The Morning Call, Morning Call (Allentown, PA), FIRST ed, pA25, Sunday, December 27, 2009 5. CORRECTIONS, OPINION BY RYAN FINLEY, ARIZONA DAILY STAR, Arizona Daily Star (AZ), FINAL ed, pA2, Saturday, December 19, 2009 6. We see a 'Super-Earth', TOM BEAL; TOM BEAL, ARIZONA DAILY STAR, Arizona Daily Star, (AZ), FINAL ed, pA1, Thursday, December 17, 2009 Record - 1 DIALOG(R) New social science research from G. Sonnert and co-researchers described, Science Letter, p40, Tuesday, January 5, 2010 TEXT: "In this paper we report on testing the 'rolen model' and 'opportunity-structure' hypotheses about the parents whom scientists mentioned as career influencers. According to the role-model hypothesis, the gender match between scientist and influencer is paramount (for example, women scientists would disproportionately often mention their mothers as career influencers)," scientists writing in the journal Social Studies of Science report (see also ). "According to the opportunity-structure hypothesis, the parent's educational level predicts his/her probability of being mentioned as a career influencer (that ism parents with higher educational levels would be more likely to be named). The examination of a sample of American scientists who had received prestigious postdoctoral fellowships resulted in rejecting the role-model hypothesis and corroborating the opportunity-structure hypothesis. -
Formation of Regular Satellites from Ancient Massive Rings in the Solar System
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