DOCSLIB.ORG

Occultations and Eclipses by BOB RIDDLE

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Occultations and Eclipses by BOB RIDDLE SCOPE ON THE SKIES Occultations and eclipses BY BOB RIDDLE n astronomy, an occultation oc- the viewing area of a solar eclipse surface. If you are not within the curs when something between but not within the path of the path, then you may experience a Iyou and a distant object blocks Moon’s shadow, you will only grazing occultation or a conjunc- your view of that distant object. see a partial eclipse of the Sun. tion, depending on your distance Occultations are regular, pre- Viewing an occultation of a from the path of occultation. Lu- dictable events because planets, star has a similar geographic re- nar conjunctions occur when the dwarf planets, moons, and as- quirement. However, to view a Moon is within a few degrees of teroids orbit the Sun and pass in total solar eclipse, you must be a planet or star, while planetary front of stars in the background. within the 100- to 274-kilometer- conjunctions occur when a planet Our Moon occults, or eclipses, wide (60 to 170 mi) shadow of is within a few degrees from a the Sun four to six times each the Moon. To view an occultation star or planet. But there are ex- year. If you are within the path of of a star, you must be within a ceptions. During the July 2011 the Moon’s shadow, you will see path of occultation that is only a occultation of the star LQ Aquarii a total eclipse. If you are within few miles wide along the Earth’s by Double Asteroid 90 Antiope, | FIGURE 1: March occultation dates Solar system object Date Occultation path maps Saturn March 1 https://bit.ly/2sjUU6k Dwarf planet Pluto March 2 https://bit.ly/2RqYKth Asteroid 2 Pallas March 3 http://asteroidoccultation.com/2019_03/0303_2_59440_Map.gif Asteroid 21 Lutetia https://bit.ly/2AIgfLe Asteroid 3 Juno March 3 http://asteroidoccultation.com/2019_03/0303_3_59444_Map.gif Dwarf planet Makemake March 9 http://asteroidoccultation.com/2019_03/0309_136472_59488_Map.gif Asteroid 358 Apollonia March 19 http://asteroidoccultation.com/2019_03/0319_358_62626_Map.gif Asteroid 2 Pallas March 21 http://asteroidoccultation.com/2019_03/0321_2_59602_Map.gif Saturn March 29 https://bit.ly/2FlnCMO Dwarf planet Pluto March 29 https://bit.ly/2M4UmdH Asteroid 21 Lutetia March 31 https://bit.ly/2AIgfLe 20 the occultation path was up to then after the star was behind didates as well. Farther away 125 miles (200 km) wide. the disk of the planet (see Re- from the ecliptic, where many Unlike a solar eclipse, there is sources). Similarly, comparing asteroid orbital paths are locat- no shadow path in occultations. observations from different lo- ed, stars are regularly occulted So, what do you see? Because cations along the path of stellar by asteroids. planets appear star-like when occultations has also allowed us either is occulted, they disap- to determine the shape of dis- pear from view as the occulting tant asteroids (see “The Shape of Occultations in March object passes across our line of Things” in Resources). 2019 sight. The length of the occul- Every month, our Moon and Several occultations occur this tation depends on the apparent asteroids are usually involved month, including two lunar oc- size of the occulting object and with occultations and conjunc- cultations with the planet Sat- the angle it moves at relative to tions, often with the same stars urn, dwarf planet Pluto, and the star being occulted. The star and planets on a regular basis. two asteroids (see Figure 1). reappears on the opposite side The Moon’s orbital path is tilted These occultations are at the be- of the occulting object moments about 6° from the Earth’s orbit, ginning and end of the month. or minutes later. called the ecliptic, so the Moon Several asteroids also have oc- Observing occultations plays is always somewhere close to or cultations with stars this month. an important role in astronomy. on the ecliptic. Several stars are While none of these occultations In possibly the most famous also on or near the ecliptic and are visible from our part of the stellar occultation, rings were may cause an occultation or con- Earth, students could examine discovered around the planet junction. The seven other plan- the occultation path to generate Uranus during its occultation ets have orbital path inclinations interests in observing an occul- of a distant star. As Uranus oc- ranging from 0.77 for Uranus to tation, or learn more about the culted, the light from the star 7.01 for Mercury, making them countries along the path of the flickered on and off before and occultation and conjunction can- ecliptic (see Figure 2). | FIGURE 2: Path of the ecliptic March 2019 21 | FIGURE 3: Table of some solar system objects with moons The moons in our solar Name and type of object Number and names of moons system Asteroid Ida 1: Dactyl An eclipse involving the Earth, our Moon, and the Sun is deter- Asteroid Eugenia 1: Petit-Prince mined by the arrangement of the Asteroid Pulcova (double asteroid) 1: S/2000 (762) 1 three objects. All Sun-orbiting Dwarf planet Pluto 5: Charon; Nix; Hydra; Kerberos; Styx objects with moons will, at some Dwarf planet Haumea 2: Hi’iaka; Namaka point in their respective orbit, experience eclipses of the Sun by its moon. Planets are not the March only objects with moons; many minor planets (including aster- 1 Moon occultation with 16 Moon at ascending node oids, dwarf planets, and Kuiper Saturn 17 Waxing gibbous Moon near belt objects) have a moon. There 2 Moon at descending node Beehive open star cluster are currently around 330 moons Waning crescent Moon 18 Waxing gibbous Moon near discovered in orbit around vari- close to Venus Regulus ous minor planets, including 143 Moon occultation with 19 Moon at perigee: 359,381 main belt asteroids and 63 near- Pluto km (223,309 mi.) Earth asteroids. Some of the mi- 3 Moon occultation with Asteroid 358 Apollonia nor planets have more than one Asteroid 21 Lutetia occultation with HIP 19036 moon, while dwarf planet Pluto Asteroid 2 Pallas (star) has five moons. Minor planets occultation with TYC 0323- 20 March equinox (21:58 with a moon are known as binary 01028-1 (star) UT–5:58 pm EDT) minor planets, while those with Asteroid 3 Juno occultation 21 Full Moon (a Super Moon) three moons are known as trinary with UCAC5 492-007098 Asteroid 2 Pallas minor planets. (star) occultation with UCAC5 In 1994, during the Galileo mis- 4 Moon at apogee: 406,391 510-053447 (star) sion to Jupiter, the first asteroid km (252,520 mi.) 23 Martian summer solstice with a moon was discovered. As 6 New Moon 27 Waning gibbous Moon near the spacecraft passed through the 7 Neptune in conjunction Jupiter main asteroid belt it took images with Sun 28 Last quarter Moon of the asteroid Ida and its one- 9 Dwarf planet Makemake 29 Moon occultation with mile-long (1.6 km) moon, which occultation with UCAC5 Saturn was later named Dactyl (see Fig- 572-047492 (Star) Moon occultation with ure 3). When the size difference 10 Begin Daylight Savings Pluto between the objects is large, (Ida Time Moon at descending node is 10 miles (16 km) long) the larg- 11 Waxing crescent Moon near 31 Mars near Pleiades open er object is sometimes called the Mars star cluster primary and the smaller called 13 Waxing crescent Moon near Moon occultation with the secondary. If the objects are Aldebaran Asteroid 21 Lutetia about the same size, it could be 14 First quarter Moon Begin European Summer called a double asteroid. Pi Day Time (set clocks ahead one The number of moons orbit- 15 Mercury at inferior hour.) ing the eight planets in our solar conjunction system changes sporadically, as 22 SCOPE ON THE SKIES new discoveries are made from examining mission data or from current observations. Recently, For students another 12 moons orbiting Ju- 1. Celestial objects are given temporary names upon discovery and piter were discovered, bringing eventually a permanent name. Certain rules are followed for nam- that planet’s known moon total ing planets and moons. What is the connection between the names to 79 (see Figure 4). Two of the of Asteroid Ida and its moon Dactyl? (In Greek mythology Ida lived eight planets, inner planets Mer- on the island of Crete and helped raise Zeus. The moon Dactyl was cury and Venus, do not have named after a group of men, the Dactyls, who lived on Mount Ida.) any orbiting natural satellites. 2. Download the free SFA equatorial star charts (see Resources). It is thought that gravity plays Tape maps 2 and 3 together so you can see the entire ecliptic path. an important role in why these Obtain daily Moon coordinate positions from the U.S. Navy Obser- two planets do not have a moon. vatory website (see Resources) and then use the right ascension They are too close to the Sun, and declination to plot and follow the Moon. and it is likely that any moon that may have formed with the planet or inbound from the outer solar system would be caught in the more powerful gravitational Visible planets field of the Sun and pulled into Mercury will appear in the morning skies over the eastern hori- the Sun. • zon during the last half of the month. Venus will be low but still bright and very visible over the east- ern horizon at sunrise. Watch for a close conjunction with the | FIGURE 4: The current Moon on the first of March. number of moons surrounding eight planets Mars will be visible over the southwestern horizon and will move within 1° to 2° from the open star cluster the Pleiades by Name of Number of the end of the month.
Load more

Recommended publications
  • The 4 Major Asteroids and Chiron Report For
    The 4 Major Asteroids and Chiron Report for Brad Roberts 10 January 1964 6:33 AM Winnipeg, Manitoba,Canada Calculated for: Standard time, Time Zone 6 hours West Latitude: 49 N 53 Longitude: 97 W 09 Positions of Planets at Birth: Sun 19 Cap 18 Asc. 20 Sag 35 Moon 1 Sag 21 MC 21 Lib 49 Mercury 6 Cap 24 2nd cusp 0 Aqu 56 Venus 21 Aqu 54 3rd cusp 17 Pis 07 Mars 27 Cap 52 5th cusp 15 Tau 45 Jupiter 11 Ari 42 6th cusp 4 Gem 07 Saturn 21 Aqu 25 Ceres 9 Sag 44 Uranus 9 Vir 47 Pallas 20 Sco 12 Neptune 17 Sco 47 Juno 23 Sco 36 Pluto 14 Vir 47 Vesta 4 Cap 54 True Node11 Can 47 Chiron 11 Pis 23 Aspects and orbs: Conjunction : 7 Deg 00 Min Trine : 5 Deg 00 Min Opposition : 6 Deg 00 Min Sextile : 3 Deg 00 Min Square : 4 Deg 00 Min Interpretations by astrologer Dave Campbell Report and Text Copyright By Cosmic Patterns Software, Inc. The contents of this report are protected by Copyright law. By purchasing this report you agree to comply with this Copyright. Libra Moon, Inc www.libramoonastrology.com www.zodiac-reports.com Chapter 1: Ceres Ceres in Sagittarius: You nurture people with your generosity cheerfulness and encouragement. Giving them the optimism and openness they need. You aim to inspire them and make them feel like they are it. Your honest disposition and behavior is also a gift for them to know your devotion to them. All of these things are exactly what you need in order to feel cared for.
    [Show full text]
  • Occultation Newsletter Volume 8, Number 4
    Volume 12, Number 1 January 2005 $5.00 North Am./$6.25 Other International Occultation Timing Association, Inc. (IOTA) In this Issue Article Page The Largest Members Of Our Solar System – 2005 . 4 Resources Page What to Send to Whom . 3 Membership and Subscription Information . 3 IOTA Publications. 3 The Offices and Officers of IOTA . .11 IOTA European Section (IOTA/ES) . .11 IOTA on the World Wide Web. Back Cover ON THE COVER: Steve Preston posted a prediction for the occultation of a 10.8-magnitude star in Orion, about 3° from Betelgeuse, by the asteroid (238) Hypatia, which had an expected diameter of 148 km. The predicted path passed over the San Francisco Bay area, and that turned out to be quite accurate, with only a small shift towards the north, enough to leave Richard Nolthenius, observing visually from the coast northwest of Santa Cruz, to have a miss. But farther north, three other observers video recorded the occultation from their homes, and they were fortuitously located to define three well- spaced chords across the asteroid to accurately measure its shape and location relative to the star, as shown in the figure. The dashed lines show the axes of the fitted ellipse, produced by Dave Herald’s WinOccult program. This demonstrates the good results that can be obtained by a few dedicated observers with a relatively faint star; a bright star and/or many observers are not always necessary to obtain solid useful observations. – David Dunham Publication Date for this issue: July 2005 Please note: The date shown on the cover is for subscription purposes only and does not reflect the actual publication date.
    [Show full text]
  • Phase Integral of Asteroids Vasilij G
    A&A 626, A87 (2019) Astronomy https://doi.org/10.1051/0004-6361/201935588 & © ESO 2019 Astrophysics Phase integral of asteroids Vasilij G. Shevchenko1,2, Irina N. Belskaya2, Olga I. Mikhalchenko1,2, Karri Muinonen3,4, Antti Penttilä3, Maria Gritsevich3,5, Yuriy G. Shkuratov2, Ivan G. Slyusarev1,2, and Gorden Videen6 1 Department of Astronomy and Space Informatics, V.N. Karazin Kharkiv National University, 4 Svobody Sq., Kharkiv 61022, Ukraine e-mail: [email protected] 2 Institute of Astronomy, V.N. Karazin Kharkiv National University, 4 Svobody Sq., Kharkiv 61022, Ukraine 3 Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2, 00560 Helsinki, Finland 4 Finnish Geospatial Research Institute FGI, Geodeetinrinne 2, 02430 Masala, Finland 5 Institute of Physics and Technology, Ural Federal University, Mira str. 19, 620002 Ekaterinburg, Russia 6 Space Science Institute, 4750 Walnut St. Suite 205, Boulder CO 80301, USA Received 31 March 2019 / Accepted 20 May 2019 ABSTRACT The values of the phase integral q were determined for asteroids using a numerical integration of the brightness phase functions over a wide phase-angle range and the relations between q and the G parameter of the HG function and q and the G1, G2 parameters of the HG1G2 function. The phase-integral values for asteroids of different geometric albedo range from 0.34 to 0.54 with an average value of 0.44. These values can be used for the determination of the Bond albedo of asteroids. Estimates for the phase-integral values using the G1 and G2 parameters are in very good agreement with the available observational data.
    [Show full text]
  • Iso and Asteroids
    r bulletin 108 Figure 1. Asteroid Ida and its moon Dactyl in enhanced colour. This colour picture is made from images taken by the Galileo spacecraft just before its closest approach to asteroid 243 Ida on 28 August 1993. The moon Dactyl is visible to the right of the asteroid. The colour is ‘enhanced’ in the sense that the CCD camera is sensitive to near-infrared wavelengths of light beyond human vision; a ‘natural’ colour picture of this asteroid would appear mostly grey. Shadings in the image indicate changes in illumination angle on the many steep slopes of this irregular body, as well as subtle colour variations due to differences in the physical state and composition of the soil (regolith). There are brighter areas, appearing bluish in the picture, around craters on the upper left end of Ida, around the small bright crater near the centre of the asteroid, and near the upper right-hand edge (the limb). This is a combination of more reflected blue light and greater absorption of near-infrared light, suggesting a difference Figure 2. This image mosaic of asteroid 253 Mathilde is in the abundance or constructed from four images acquired by the NEAR spacecraft composition of iron-bearing on 27 June 1997. The part of the asteroid shown is about 59 km minerals in these areas. Ida’s by 47 km. Details as small as 380 m can be discerned. The moon also has a deeper near- surface exhibits many large craters, including the deeply infrared absorption and a shadowed one at the centre, which is estimated to be more than different colour in the violet than any 10 km deep.
    [Show full text]
  • Appendix 1 1311 Discoverers in Alphabetical Order
    Appendix 1 1311 Discoverers in Alphabetical Order Abe, H. 28 (8) 1993-1999 Bernstein, G. 1 1998 Abe, M. 1 (1) 1994 Bettelheim, E. 1 (1) 2000 Abraham, M. 3 (3) 1999 Bickel, W. 443 1995-2010 Aikman, G. C. L. 4 1994-1998 Biggs, J. 1 2001 Akiyama, M. 16 (10) 1989-1999 Bigourdan, G. 1 1894 Albitskij, V. A. 10 1923-1925 Billings, G. W. 6 1999 Aldering, G. 4 1982 Binzel, R. P. 3 1987-1990 Alikoski, H. 13 1938-1953 Birkle, K. 8 (8) 1989-1993 Allen, E. J. 1 2004 Birtwhistle, P. 56 2003-2009 Allen, L. 2 2004 Blasco, M. 5 (1) 1996-2000 Alu, J. 24 (13) 1987-1993 Block, A. 1 2000 Amburgey, L. L. 2 1997-2000 Boattini, A. 237 (224) 1977-2006 Andrews, A. D. 1 1965 Boehnhardt, H. 1 (1) 1993 Antal, M. 17 1971-1988 Boeker, A. 1 (1) 2002 Antolini, P. 4 (3) 1994-1996 Boeuf, M. 12 1998-2000 Antonini, P. 35 1997-1999 Boffin, H. M. J. 10 (2) 1999-2001 Aoki, M. 2 1996-1997 Bohrmann, A. 9 1936-1938 Apitzsch, R. 43 2004-2009 Boles, T. 1 2002 Arai, M. 45 (45) 1988-1991 Bonomi, R. 1 (1) 1995 Araki, H. 2 (2) 1994 Borgman, D. 1 (1) 2004 Arend, S. 51 1929-1961 B¨orngen, F. 535 (231) 1961-1995 Armstrong, C. 1 (1) 1997 Borrelly, A. 19 1866-1894 Armstrong, M. 2 (1) 1997-1998 Bourban, G. 1 (1) 2005 Asami, A. 7 1997-1999 Bourgeois, P. 1 1929 Asher, D.
    [Show full text]
  • Nasa Technical Memorandum .1
    NASA TECHNICAL MEMORANDUM NASA TM X-64677 COMETS AND ASTEROIDS: A Strategy for Exploration REPORT OF THE COMET AND ASTEROID MISSION STUDY PANEL May 1972 .1!vP -V (NASA-TE-X- 6 q767 ) COMETS AND ASTEROIDS: A RR EXPLORATION (NASA) May 1972 CSCL 03A NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Reproduced by ' NATIONAL "TECHINICAL INFORMATION: SERVICE US Depdrtmett ofCommerce :. Springfield VA 22151 TECHNICAL REPORT STANDARD TITLE PAGE · REPORT NO. 2. GOVERNMENT ACCESSION NO. 3, RECIPIENT'S CATALOG NO. NASA TM X-64677 . TITLE AND SUBTITLE 5. REPORT aE COMETS AND ASTEROIDS ___1_ A Strategy for Exploration 6. PERFORMING ORGANIZATION CODE AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT # Comet and Asteroid Mission Study Panel PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NO. 11. CONTRACT OR GRANT NO. 13. TYPE OF REPORT & PERIOD COVERED 2. SPONSORING AGENCY NAME AND ADDRESS National Aeronautics and Space Administration Technical Memorandum Washington, D. C. 20546 14. SPONSORING AGENCY CODE 5. SUPPLEMENTARY NOTES ABSTRACT Many of the asteroids probably formed near the orbits where they are found today. They accreted from gases and particles that represented the primordial solar system cloud at that location. Comets, in contrast to asteroids, probably formed far out in the solar system, and at very low temperatures; since they have retained their volatile components they are probably the most primordial matter that presently can be found anywhere in the solar system. Exploration and detailed study of comets and asteroids, therefore, should be a significant part of NASA's efforts to understand the solar system. A comet and asteroid program should consist of six major types of projects: ground-based observations;Earth-orbital observations; flybys; rendezvous; landings; and sample returns.
    [Show full text]
  • The 4 Major Asteroids and Chiron Report For
    The 4 Major Asteroids and Chiron Report for Oprah Winfrey 29 January 1954 4:30 Kosciusko, Mississippi Calculated for: Standard time, Time Zone 6 hours West Latitude: 33 N 03 27 Longitude: 89 W 35 15 Positions of Planets at Birth: Sun 9 Aqu 00 Asc. 29 Sag 41 Moon 4 Sag 32 MC 17 Lib 25 Mercury 19 Aqu 09 2nd cusp 5 Aqu 04 Venus 8 Aqu 51 3rd cusp 13 Pis 19 Mars 23 Sco 35 5th cusp 14 Tau 52 Jupiter 16 Gem 39 6th cusp 7 Gem 52 Saturn 9 Sco 03 Ceres 12 Lib 47 Uranus 20 Can 19 Pallas 6 Vir 23 Neptune 26 Lib 19 Juno 21 Leo 57 Pluto 24 Leo 19 Vesta 22 Pis 14 True Node23 Cap 19 Chiron 23 Cap 35 Aspects and orbs: Conjunction : 7 Deg 00 Min Trine : 5 Deg 00 Min Opposition : 6 Deg 00 Min Sextile : 3 Deg 00 Min Square : 4 Deg 00 Min Interpretations by astrologer Dave Campbell Report and Text Copyright By Cosmic Patterns Software, Inc. The contents of this report are protected by Copyright law. By purchasing this report you agree to comply with this Copyright. Profesional Astro Reports www.astro-reports.com [email protected] Chapter 1: Ceres Ceres in Libra: In order for you to feel nurtured you need to be treated with kindness, and harmony. You need cooperation to feel whole and loved, so the need to be in a relationship is strong with this placement. You are the peacemaker and that is how you nurture others, through kindness, sympathy, fairness and understanding.
    [Show full text]
  • Asteroids and Tnos
    Main Belt Trailing Trojans Apollos, Atens, Amors Jupiter 3:1 5:2 7:3 4:1 2:1 3:2 1:1 7:2 Hildas Trojans Floras Some Named Asteroids 1 Ceres 4147 Lennon 2 Pallas 4148 McCartney 3 Juno 4149 Harrison 4 Vesta 4150 Starr 5 Astrea 4305 Clapton 439 Ohio 4442 Garcia 1814 Bach 6433 Enya 1815 Beethoven 10185 Gaudi 1818 Brahms 110393 Rammstein Sizes of Asteroids Largest asteroid is Ceres: • 914 km across • Mass of 0.0002 MEarth • Dwarf Planet Most are much smaller: • Only ~100 are >140 km across. • ~1.2 Million are >1 km across. • Total mass in asteroids is only ~0.0006 MEarth enough for a small rocky body • Half the mass is in the largest 4 asteroids. Vesta Moon Ceres Vesta from the Dawn Spacecraft Moons of Asteroids Ida and Dactyl Composition Classify asteroids by their colors • C-type: Carbonaceous - dark in color, composed of carbonaceous materials (~75%) • S-type: Silicaceous - reddish in color, stony or stony iron (~16%) • M-type: Metallic - bluer than S-type & probably iron-rich Rest are oddball types. Monoliths or Rubble Piles? Some asteroids are clearly solid: • Densities of 3-5 g/cc, like solid rock/metals • Heavily cratered surfaces & dusty regoliths Others appear to be rubble piles: • Lower in density (1-2 g/cc) • Loose aggregates of rock held together by mutual gravity • Formerly solid but shattered by impacts? 253 Mathilda density ~1.3 g/cc 25143 Itokawa density ~2.3 g/cc Trans-Neptunian Objects Class of icy bodies that orbit beyond Neptune: • Range from 30 AU outward Dwarf planets: • Pluto, Eris, Haumea, Makemake Divided into various orbital classes: • Kuiper Belt Objects • Plutinos ("little Plutos") • Scattered Disk Objects Dwarf Planets Pluto Orbit • a=39.48 AU, P=366.7 yr • Orbit is very tilted (17°) & very elliptical (e=0.249) Surface • Barely resolved even with HST • Best resolution from eclipses 3:2 (Plutinos) 2:1 Leftover Raw Materials Trans-Neptunian Objects are the icy planetesimals leftover from the formation of the Solar System.
    [Show full text]
  • Opposition Optical Phenomena in Planetary Astrophysics: Observational Results
    Opposition optical phenomena in planetary astrophysics: observational results Vera K. Rosenbush1* and Michael I. Mishchenko2 1 Main Astronomical Observatory of the National Academy of Sciences of Ukraine, 27 Akademika Zabolotnoho St., 03680 Kyiv, Ukraine 2 NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA Abstract. The photometric phenomenon in the form of a nonlinear increase of brightness at small phase angles and a negative branch of polarization are typical of the majority of Solar System bodies. In addition, some high-albedo objects re- veal a backscattering polarization feature in the form of a spike-like negative- polarization minimum called the polarization opposition effect. These optical phe- nomena are important tests of our theoretical descriptions of light scattering by re- golith planetary surfaces. In this chapter we review the recent progress in the study of optical opposition phenomena in planetary astrophysics. We primarily focus on the results of polarimetric observations of asteroids, the Galilean satellites of Jupi- ter, the Saturnian satellite Iapetus, Centaurs, and trans-Neptunian objects at back- scattering geometries including phase angles approaching zero. Keywords: polarimetry, opposition effects, asteroids, satellites, Centaurs, trans-Neptunian objects 1. Introduction Polarimetry and photometry are especially sensitive diagnostic tools helping to infer the physical properties of bodies whose observational characteristics are governed by small scatterers, e.g., dust and regolith grains. It is these methods that have provided convincing indications of the presence of regolith on planetary sur- faces long before the advent of space missions. Measurements of the intensity and polarization of scattered light as functions of the phase angle and wavelength have been used to gain an improved understanding of the microphysical properties of the surfaces of many Solar System bodies.
    [Show full text]
  • The British Astronomical Association Handbook 2014
    THE HANDBOOK OF THE BRITISH ASTRONOMICAL ASSOCIATION 2015 2014 October ISSN 0068–130–X CONTENTS CALENDAR 2015 . 2 PREFACE . 3 HIGHLIGHTS FOR 2015 . 4 SKY DIARY . .. 5 VISIBILITY OF PLANETS . 6 RISING AND SETTING OF THE PLANETS IN LATITUDES 52°N AND 35°S . 7-8 ECLIPSES . 9-14 TIME . 15-16 EARTH AND SUN . 17-19 LUNAR LIBRATION . 20 MOON . 21 MOONRISE AND MOONSET . 21-25 SUN’S SELENOGRAPHIC COLONGITUDE . 26 LUNAR OCCULTATIONS . 27-33 GRAZING LUNAR OCCULTATIONS . 34-35 APPEARANCE OF PLANETS . 36 MERCURY . 37-38 VENUS . 39 MARS . 40-41 ASTEROIDS . 42 ASTEROID EPHEMERIDES . 43-47 ASTEROID OCCULTATIONS .. 48-50 NEO CLOSE APPROACHES TO EARTH . 51 ASTEROIDS: FAVOURABLE OBSERVING OPPORTUNITIES . 52-54 JUPITER . 55-59 SATELLITES OF JUPITER . 59-63 JUPITER ECLIPSES, OCCULTATIONS AND TRANSITS . 64-73 SATURN . 74-77 SATELLITES OF SATURN . 78-81 URANUS . 82 NEPTUNE . 83 TRANS–NEPTUNIAN & SCATTERED DISK OBJECTS . 84 DWARF PLANETS . 85-88 COMETS . 89-96 METEOR DIARY . 97-99 VARIABLE STARS (RZ Cassiopeiae; Algol; λ Tauri) . 100-101 MIRA STARS . 102 VARIABLE STAR OF THE YEAR (V Bootis) . 103-105 EPHEMERIDES OF DOUBLE STARS . 106-107 BRIGHT STARS . 108 ACTIVE GALAXIES . 109 PLANETS – EXPLANATION OF TABLES . 110 ELEMENTS OF PLANETARY ORBITS . 111 ASTRONOMICAL AND PHYSICAL CONSTANTS . 111-112 INTERNET RESOURCES . 113-114 GREEK ALPHABET . 115 ACKNOWLEDGEMENTS . 116 ERRATA . 116 Front Cover: The Moon at perigee and apogee – highlighting the clear size difference when the Moon is closest and farthest away from the Earth. Perigee on 2009/11/08 at 23:24UT, distance
    [Show full text]
  • Planets Solar System Paper Contents
    Planets Solar system paper Contents 1 Jupiter 1 1.1 Structure ............................................... 1 1.1.1 Composition ......................................... 1 1.1.2 Mass and size ......................................... 2 1.1.3 Internal structure ....................................... 2 1.2 Atmosphere .............................................. 3 1.2.1 Cloud layers ......................................... 3 1.2.2 Great Red Spot and other vortices .............................. 4 1.3 Planetary rings ............................................ 4 1.4 Magnetosphere ............................................ 5 1.5 Orbit and rotation ........................................... 5 1.6 Observation .............................................. 6 1.7 Research and exploration ....................................... 6 1.7.1 Pre-telescopic research .................................... 6 1.7.2 Ground-based telescope research ............................... 7 1.7.3 Radiotelescope research ................................... 8 1.7.4 Exploration with space probes ................................ 8 1.8 Moons ................................................. 9 1.8.1 Galilean moons ........................................ 10 1.8.2 Classification of moons .................................... 10 1.9 Interaction with the Solar System ................................... 10 1.9.1 Impacts ............................................ 11 1.10 Possibility of life ........................................... 12 1.11 Mythology .............................................
    [Show full text]
  • Catching Asteroid 3 Juno at Its Best 14 November 2018, by David Dickinson
    Catching asteroid 3 Juno at its best 14 November 2018, by David Dickinson bashful Juno only reaches a favorable opposition once every 13 years. Witness last year's unfavorable opposition, when Juno shined two full magnitudes (over six times) fainter, at magnitude +9.8. Credit: Harvard-Smithsonian Center for Astrophysics. Not all oppositions are created equal. This week's sky target offers a good case in point, as asteroid 3 Juno reaches its most favorable viewing position The path of 3 Juno from mid-November 2018, through for the decade. the end of January 2019. Credit: Starry Night Juno in 2018 Juno reaches opposition on Thursday, November This is the best viewing season for 3 Juno since 16th, 2018 at around 22:00 Universal Time (UT) or 2005, and the best until its favorable 2031 pass. In 5:00 PM U.S. Eastern Standard Time (EST). This fact, at 1.036 distant, the 2018 apparition is one of means the asteroid rises opposite to the setting the best for the 21st century, nudging out 2005 sun this week, riding highest in the sky as it transits (1.063 AU) and 2031 (1.044 AU). due south. It also makes its closest approach to the Earth about 14 hours prior on the same date, 3 Juno was discovered by astronomer Karl Ludwig at 159 million kilometers distant. From mid- Harding on the night of September 1st, 1804, using northern latitudes, the asteroid transits 45 degrees a small 5-centimeter refracting telescope at the above the southern horizon at its highest. The Lilienthal Observatory in Bremen, Germany.
    [Show full text]