Notes on the Venus/Sun Cycle
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Phases of Venus and Galileo
Galileo and the phases of Venus I) Periods of Venus 1) Synodical period and phases The synodic period1 of Venus is 584 days The superior2 conjunction occured on 11 may 1610. Calculate the date of the quadrature, of the inferior conjunction and of the next superior conjunction, supposing the motions of the Earth and Venus are circular and uniform. In fact the next superior conjunction occured on 11 december 1611 and inferior conjunction on 26 february 1611. 2) Sidereal period The sidereal period of the Earth is 365.25 days. Calculate the sidereal period of Venus. II) Phases on Venus in geo and heliocentric models 1) Phases in differents models 1) Determine the phases of Venus in geocentric models, where the Earth is at the center of the universe and planets orbit around (Venus “above” or “below” the sun) * Pseudo-Aristoteles model : Earth (center)-Moon-Sun-Mercury-Venus-Mars-Jupiter-Saturne * Ptolemeo’s model : Earth (center)-Moon-Mercury-Venus-Sun-Mars-Jupiter-Saturne 2) Determine the phases of Venus in the heliocentric model, where planets orbit around the sun. Copernican system : Sun (center)-Mercury-Venus-Earth-Mars-Jupiter-Saturne 2) Observations of Galileo Galileo (1564-1642) observed Venus in 1610-1611 with a telescope. Read the letters of Galileo. May we conclude that the Copernican model is the only one available ? When did Galileo begins to observe Venus? Give the approximate dates of the quadrature and of the inferior conjunction? What are the approximate dates of the 5 observations of Galileo supposing the figure from the Essayer, was drawn in 1610-1611 1 The synodic period is the time that it takes for the object to reappear at the same point in the sky, relative to the Sun, as observed from Earth; i.e. -
Planetary Phase Variations of the 55 Cancri System
The Astrophysical Journal, 740:61 (7pp), 2011 October 20 doi:10.1088/0004-637X/740/2/61 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. PLANETARY PHASE VARIATIONS OF THE 55 CANCRI SYSTEM Stephen R. Kane1, Dawn M. Gelino1, David R. Ciardi1, Diana Dragomir1,2, and Kaspar von Braun1 1 NASA Exoplanet Science Institute, Caltech, MS 100-22, 770 South Wilson Avenue, Pasadena, CA 91125, USA; [email protected] 2 Department of Physics & Astronomy, University of British Columbia, Vancouver, BC V6T1Z1, Canada Received 2011 May 6; accepted 2011 July 21; published 2011 September 29 ABSTRACT Characterization of the composition, surface properties, and atmospheric conditions of exoplanets is a rapidly progressing field as the data to study such aspects become more accessible. Bright targets, such as the multi-planet 55 Cancri system, allow an opportunity to achieve high signal-to-noise for the detection of photometric phase variations to constrain the planetary albedos. The recent discovery that innermost planet, 55 Cancri e, transits the host star introduces new prospects for studying this system. Here we calculate photometric phase curves at optical wavelengths for the system with varying assumptions for the surface and atmospheric properties of 55 Cancri e. We show that the large differences in geometric albedo allows one to distinguish between various surface models, that the scattering phase function cannot be constrained with foreseeable data, and that planet b will contribute significantly to the phase variation, depending upon the surface of planet e. We discuss detection limits and how these models may be used with future instrumentation to further characterize these planets and distinguish between various assumptions regarding surface conditions. -
Planet Positions: 1 Planet Positions
Planet Positions: 1 Planet Positions As the planets orbit the Sun, they move around the celestial sphere, staying close to the plane of the ecliptic. As seen from the Earth, the angle between the Sun and a planet -- called the elongation -- constantly changes. We can identify a few special configurations of the planets -- those positions where the elongation is particularly noteworthy. The inferior planets -- those which orbit closer INFERIOR PLANETS to the Sun than Earth does -- have configurations as shown: SC At both superior conjunction (SC) and inferior conjunction (IC), the planet is in line with the Earth and Sun and has an elongation of 0°. At greatest elongation, the planet reaches its IC maximum separation from the Sun, a value GEE GWE dependent on the size of the planet's orbit. At greatest eastern elongation (GEE), the planet lies east of the Sun and trails it across the sky, while at greatest western elongation (GWE), the planet lies west of the Sun, leading it across the sky. Best viewing for inferior planets is generally at greatest elongation, when the planet is as far from SUPERIOR PLANETS the Sun as it can get and thus in the darkest sky possible. C The superior planets -- those orbiting outside of Earth's orbit -- have configurations as shown: A planet at conjunction (C) is lined up with the Sun and has an elongation of 0°, while a planet at opposition (O) lies in the opposite direction from the Sun, at an elongation of 180°. EQ WQ Planets at quadrature have elongations of 90°. -
On the Use of Planetary Science Data for Studying Extrasolar Planets a Science Frontier White Paper Submitted to the Astronomy & Astrophysics 2020 Decadal Survey
On the Use of Planetary Science Data for Studying Extrasolar Planets A science frontier white paper submitted to the Astronomy & Astrophysics 2020 Decadal Survey Thematic Area: Planetary Systems Principal Author Daniel J. Crichton Jet Propulsion Laboratory, California Institute of Technology [email protected] 818-354-9155 Co-Authors: J. Steve Hughes, Gael Roudier, Robert West, Jeffrey Jewell, Geoffrey Bryden, Mark Swain, T. Joseph W. Lazio (Jet Propulsion Laboratory, California Institute of Technology) There is an opportunity to advance both solar system and extrasolar planetary studies that does not require the construction of new telescopes or new missions but better use and access to inter-disciplinary data sets. This approach leverages significant investment from NASA and international space agencies in exploring this solar system and using those discoveries as “ground truth” for the study of extrasolar planets. This white paper illustrates the potential, using phase curves and atmospheric modeling as specific examples. A key advance required to realize this potential is to enable seamless discovery and access within and between planetary science and astronomical data sets. Further, seamless data discovery and access also expands the availability of science, allowing researchers and students at a variety of institutions, equipped only with Internet access and a decent computer to conduct cutting-edge research. © 2019 California Institute of Technology. Government sponsorship acknowledged. Pre-decisional - For planning -
The Midnight Sky: Familiar Notes on the Stars and Planets, Edward Durkin, July 15, 1869 a Good Way to Start – Find North
The expression "dog days" refers to the period from July 3 through Aug. 11 when our brightest night star, SIRIUS (aka the dog star), rises in conjunction* with the sun. Conjunction, in astronomy, is defined as the apparent meeting or passing of two celestial bodies. TAAS Fabulous Fifty A program for those new to astronomy Friday Evening, July 20, 2018, 8:00 pm All TAAS and other new and not so new astronomers are welcome. What is the TAAS Fabulous 50 Program? It is a set of 4 meetings spread across a calendar year in which a beginner to astronomy learns to locate 50 of the most prominent night sky objects visible to the naked eye. These include stars, constellations, asterisms, and Messier objects. Methodology 1. Meeting dates for each season in year 2018 Winter Jan 19 Spring Apr 20 Summer Jul 20 Fall Oct 19 2. Locate the brightest and easiest to observe stars and associated constellations 3. Add new prominent constellations for each season Tonight’s Schedule 8:00 pm – We meet inside for a slide presentation overview of the Summer sky. 8:40 pm – View night sky outside The Midnight Sky: Familiar Notes on the Stars and Planets, Edward Durkin, July 15, 1869 A Good Way to Start – Find North Polaris North Star Polaris is about the 50th brightest star. It appears isolated making it easy to identify. Circumpolar Stars Polaris Horizon Line Albuquerque -- 35° N Circumpolar Stars Capella the Goat Star AS THE WORLD TURNS The Circle of Perpetual Apparition for Albuquerque Deneb 1 URSA MINOR 2 3 2 URSA MAJOR & Vega BIG DIPPER 1 3 Draco 4 Camelopardalis 6 4 Deneb 5 CASSIOPEIA 5 6 Cepheus Capella the Goat Star 2 3 1 Draco Ursa Minor Ursa Major 6 Camelopardalis 4 Cassiopeia 5 Cepheus Clock and Calendar A single map of the stars can show the places of the stars at different hours and months of the year in consequence of the earth’s two primary movements: Daily Clock The rotation of the earth on it's own axis amounts to 360 degrees in 24 hours, or 15 degrees per hour (360/24). -
SFSC Search Down to 4
C M Y K www.newssun.com EWS UN NHighlands County’s Hometown-S Newspaper Since 1927 Rivalry rout Deadly wreck in Polk Harris leads Lake 20-year-old woman from Lake Placid to shutout of AP Placid killed in Polk crash SPORTS, B1 PAGE A2 PAGE B14 Friday-Saturday, March 22-23, 2013 www.newssun.com Volume 94/Number 35 | 50 cents Forecast Fire destroys Partly sunny and portable at Fred pleasant High Low Wild Elementary Fire alarms “Myself, Mr. (Wally) 81 62 Cox and other administra- Complete Forecast went off at 2:40 tors were all called about PAGE A14 a.m. Wednesday 3 a.m.,” Waldron said Wednesday morning. Online By SAMANTHA GHOLAR Upon Waldron’s arrival, [email protected] the Sebring Fire SEBRING — Department along with Investigations into a fire DeSoto City Fire early Wednesday morning Department, West Sebring on the Fred Wild Volunteer Fire Department Question: Do you Elementary School cam- and Sebring Police pus are under way. Department were all on think the U.S. govern- The school’s fire alarms the scene. ment would ever News-Sun photo by KATARA SIMMONS Rhoda Ross reads to youngsters Linda Saraniti (from left), Chyanne Carroll and Camdon began going off at approx- State Fire Marshal seize money from pri- Carroll on Wednesday afternoon at the Lake Placid Public Library. Ross was reading from imately 2:40 a.m. and con- investigator Raymond vate bank accounts a children’s book she wrote and illustrated called ‘A Wildflower for all Seasons.’ tinued until about 3 a.m., Miles Davis was on the like is being consid- according to FWE scene for a large part of ered in Cyprus? Principal Laura Waldron. -
Make up Lab: Phases of Venus Introduction Galileo Is Justifiably Famous for Many Discoveries in Both Physics and Astronomy
PHYS 1401: Descriptive Astronomy Summer 2016 Make Up Lab: Phases of Venus Introduction Galileo is justifiably famous for many discoveries in both physics and astronomy. While he was fascinated by gravity and kinematics, his most valuable discovery is arguably the phases of Venus. By carefully observing and recording the progression of Venus through phases similar to our own moon, he was able to demonstrate the impossibility of the Ptolemy’s increasingly complicated geocentric model. 4. Orient yourself: Toggle on the constellation outlines and labels. Locate one or two constellations whose shapes you know. Are the constellations of 1610 recognizable to you? Face north and locate Polaris. Comment on the location of Polaris compared to its position today. Synodic Period of Venus The synodic period of an object is a measure of its motion with respect to Earth. We are most familiar with this idea as applied to the moon: to measure its synodic period, we count the time between successive full moons (or new moons, or whichever phase you like). As Galileo discovered, we can do precisely the same thing for Venus. 5. Change the date and locate Venus: Advance your date to May 01, 1610. Keep the time set to 00:00:00. Locate Venus, and zoom in to notice its phase. Advance your day until Venus Using the Stellarium program, we can replicate his is fully illuminated (100.0%) and record the date. Use the table observations by placing ourselves in the same time and place below as a model for recording your data. as Galileo himself. 6. -
Dawn Spacecraft Begins Approach to Dwarf Planet Ceres 30 December 2014, by Elizabeth Landau
Dawn spacecraft begins approach to dwarf planet Ceres 30 December 2014, by Elizabeth Landau 2012, capturing detailed images and data about that body. "Ceres is almost a complete mystery to us," said Christopher Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles. "Ceres, unlike Vesta, has no meteorites linked to it to help reveal its secrets. All we can predict with confidence is that we will be surprised." The two planetary bodies are thought to be different in a few important ways. Ceres may have formed later than Vesta, and with a cooler interior. Current evidence suggests that Vesta only retained a small This artist's concept shows NASA's Dawn spacecraft amount of water because it formed earlier, when heading toward the dwarf planet Ceres. Credit: radioactive material was more abundant, which NASA/JPL-Caltech would have produced more heat. Ceres, in contrast, has a thick ice mantle and may even have an ocean beneath its icy crust. (Phys.org)—NASA's Dawn spacecraft has entered Ceres, with an average diameter of 590 miles (950 an approach phase in which it will continue to close kilometers), is also the largest body in the asteroid in on Ceres, a Texas-sized dwarf planet never belt, the strip of solar system real estate between before visited by a spacecraft. Dawn launched in Mars and Jupiter. By comparison, Vesta has an 2007 and is scheduled to enter Ceres orbit in average diameter of 326 miles (525 kilometers), March 2015. and is the second most massive body in the belt. -
ON the INCLINATION DEPENDENCE of EXOPLANET PHASE SIGNATURES Stephen R
The Astrophysical Journal, 729:74 (6pp), 2011 March 1 doi:10.1088/0004-637X/729/1/74 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. ON THE INCLINATION DEPENDENCE OF EXOPLANET PHASE SIGNATURES Stephen R. Kane and Dawn M. Gelino NASA Exoplanet Science Institute, Caltech, MS 100-22, 770 South Wilson Avenue, Pasadena, CA 91125, USA; [email protected] Received 2011 December 2; accepted 2011 January 5; published 2011 February 10 ABSTRACT Improved photometric sensitivity from space-based telescopes has enabled the detection of phase variations for a small sample of hot Jupiters. However, exoplanets in highly eccentric orbits present unique opportunities to study the effects of drastically changing incident flux on the upper atmospheres of giant planets. Here we expand upon previous studies of phase functions for these planets at optical wavelengths by investigating the effects of orbital inclination on the flux ratio as it interacts with the other effects induced by orbital eccentricity. We determine optimal orbital inclinations for maximum flux ratios and combine these calculations with those of projected separation for application to coronagraphic observations. These are applied to several of the known exoplanets which may serve as potential targets in current and future coronagraph experiments. Key words: planetary systems – techniques: photometric 1. INTRODUCTION and inclination for a given eccentricity. We further calculate projected separations at apastron as a function of inclination The changing phases of an exoplanet as it orbits the host star and determine their correspondence with maximum flux ratio have long been considered as a means for their detection and locations. -
Stellium Handbook Part
2 Donna Cunningham’s Books on the Outer Planets If you’re dealing with a stellium that contains one or more outer planets, these ebooks will help you understand their role in your chart and explore ways to change difficult patterns they represent. Since The Stellium Handbook can’t cover them in the depth they deserve, you’ll gain a greater perspective through these ebooks that devote entire chapters to the meanings of Uranus, Neptune, or Pluto in a variety of contexts. The Outer Planets and Inner Life volumes are $15 each if purchased separately, or $35 for all three—a $10 savings. To order, go to PayPal.com and tell them which books you want, Donna’s email address ([email protected]), and the amount. The ebooks arrive on separate emails. If you want them sent to an email address other than the one you used, let her know. The Outer Planets and Inner Life, V.1: The Outer Planets as Career Indicators. If your stellium has outer planets in the career houses (2nd, 6th, or 10th), or if it relates to your chosen career, this book can give you helpful insights. There’s an otherworldly element when the outer planets are career markers, a sense of serving a greater purpose in human history. Each chapter of this e-book explores one of these planets in depth. See an excerpt here. The Outer Planets and Inner Life, v.2: Outer Planet Aspects to Venus and Mars. Learn about the love lives of people who have the outer planets woven in with the primary relationship planets, Venus and Mars, or in the relationship houses—the 7th, 8th, and 5th. -
Communications with Mars During Periods of Solar Conjunction: Initial Study Results
IPN Progress Report 42-147 November 15, 2001 Communications with Mars During Periods of Solar Conjunction: Initial Study Results D. Morabito1 and R. Hastrup2 During the initial phase of the human exploration of Mars, a reliable commu- nications link to and from Earth will be required. The direct link can easily be maintained during most of the 780-day Earth–Mars synodic period. However, dur- ing periods in which the direct Earth–Mars link encounters increased intervening charged particles during superior solar conjunctions of Mars, the resultant eects are expected to corrupt the data signals to varying degrees. The purpose of this article is to explore possible strategies, provide recommendations, and identify op- tions for communicating over this link during periods of solar conjunctions. A sig- nicant improvement in telemetry data return can be realized by using the higher frequency 32 GHz (Ka-band), which is less susceptible to solar eects. During the era of the onset of probable human exploration of Mars, six superior conjunctions were identied from 2015 to 2026. For ve of these six conjunctions, where the sig- nal source is not occulted by the disk of the Sun, continuous communications with Mars should be achievable. Only during the superior conjunction of 2023 is the signal source at Mars expected to lie behind the disk of the Sun for about one day and within two solar radii (0.5 deg) for about three days. I. Introduction During the initial phase of the human exploration of Mars, a reliable communications link to and from Earth will be required. -
Dawn Mission to Vesta and Ceres Symbiosis Between Terrestrial Observations and Robotic Exploration
Earth Moon Planet (2007) 101:65–91 DOI 10.1007/s11038-007-9151-9 Dawn Mission to Vesta and Ceres Symbiosis between Terrestrial Observations and Robotic Exploration C. T. Russell Æ F. Capaccioni Æ A. Coradini Æ M. C. De Sanctis Æ W. C. Feldman Æ R. Jaumann Æ H. U. Keller Æ T. B. McCord Æ L. A. McFadden Æ S. Mottola Æ C. M. Pieters Æ T. H. Prettyman Æ C. A. Raymond Æ M. V. Sykes Æ D. E. Smith Æ M. T. Zuber Received: 21 August 2007 / Accepted: 22 August 2007 / Published online: 14 September 2007 Ó Springer Science+Business Media B.V. 2007 Abstract The initial exploration of any planetary object requires a careful mission design guided by our knowledge of that object as gained by terrestrial observers. This process is very evident in the development of the Dawn mission to the minor planets 1 Ceres and 4 Vesta. This mission was designed to verify the basaltic nature of Vesta inferred both from its reflectance spectrum and from the composition of the howardite, eucrite and diogenite meteorites believed to have originated on Vesta. Hubble Space Telescope observations have determined Vesta’s size and shape, which, together with masses inferred from gravitational perturbations, have provided estimates of its density. These investigations have enabled the Dawn team to choose the appropriate instrumentation and to design its orbital operations at Vesta. Until recently Ceres has remained more of an enigma. Adaptive-optics and HST observations now have provided data from which we can begin C. T. Russell (&) IGPP & ESS, UCLA, Los Angeles, CA 90095-1567, USA e-mail: [email protected] F.