The Freedom Or Soviet Space Story
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The Surrender Software
Scientific image rendering for space scenes with the SurRender software Scientific image rendering for space scenes with the SurRender software R. Brochard, J. Lebreton*, C. Robin, K. Kanani, G. Jonniaux, A. Masson, N. Despré, A. Berjaoui Airbus Defence and Space, 31 rue des Cosmonautes, 31402 Toulouse Cedex, France [email protected] *Corresponding Author Abstract The autonomy of spacecrafts can advantageously be enhanced by vision-based navigation (VBN) techniques. Applications range from manoeuvers around Solar System objects and landing on planetary surfaces, to in -orbit servicing or space debris removal, and even ground imaging. The development and validation of VBN algorithms for space exploration missions relies on the availability of physically accurate relevant images. Yet archival data from past missions can rarely serve this purpose and acquiring new data is often costly. Airbus has developed the image rendering software SurRender, which addresses the specific challenges of realistic image simulation with high level of representativeness for space scenes. In this paper we introduce the software SurRender and how its unique capabilities have proved successful for a variety of applications. Images are rendered by raytracing, which implements the physical principles of geometrical light propagation. Images are rendered in physical units using a macroscopic instrument model and scene objects reflectance functions. It is specially optimized for space scenes, with huge distances between objects and scenes up to Solar System size. Raytracing conveniently tackles some important effects for VBN algorithms: image quality, eclipses, secondary illumination, subpixel limb imaging, etc. From a user standpoint, a simulation is easily setup using the available interfaces (MATLAB/Simulink, Python, and more) by specifying the position of the bodies (Sun, planets, satellites, …) over time, complex 3D shapes and material surface properties, before positioning the camera. -
Monte Carlo Methods to Calculate Impact Probabilities⋆
A&A 569, A47 (2014) Astronomy DOI: 10.1051/0004-6361/201423966 & c ESO 2014 Astrophysics Monte Carlo methods to calculate impact probabilities? H. Rickman1;2, T. Wisniowski´ 1, P. Wajer1, R. Gabryszewski1, and G. B. Valsecchi3;4 1 P.A.S. Space Research Center, Bartycka 18A, 00-716 Warszawa, Poland e-mail: [email protected] 2 Dept. of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden 3 IAPS-INAF, via Fosso del Cavaliere 100, 00133 Roma, Italy 4 IFAC-CNR, via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy Received 9 April 2014 / Accepted 28 June 2014 ABSTRACT Context. Unraveling the events that took place in the solar system during the period known as the late heavy bombardment requires the interpretation of the cratered surfaces of the Moon and terrestrial planets. This, in turn, requires good estimates of the statistical impact probabilities for different source populations of projectiles, a subject that has received relatively little attention, since the works of Öpik(1951, Proc. R. Irish Acad. Sect. A, 54, 165) and Wetherill(1967, J. Geophys. Res., 72, 2429). Aims. We aim to work around the limitations of the Öpik and Wetherill formulae, which are caused by singularities due to zero denominators under special circumstances. Using modern computers, it is possible to make good estimates of impact probabilities by means of Monte Carlo simulations, and in this work, we explore the available options. Methods. We describe three basic methods to derive the average impact probability for a projectile with a given semi-major axis, eccentricity, and inclination with respect to a target planet on an elliptic orbit. -
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur
Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur To cite this version: Alex Soumbatov-Gur. Phobos, Deimos: Formation and Evolution. [Research Report] Karpov institute of physical chemistry. 2019. hal-02147461 HAL Id: hal-02147461 https://hal.archives-ouvertes.fr/hal-02147461 Submitted on 4 Jun 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Phobos, Deimos: Formation and Evolution Alex Soumbatov-Gur The moons are confirmed to be ejected parts of Mars’ crust. After explosive throwing out as cone-like rocks they plastically evolved with density decays and materials transformations. Their expansion evolutions were accompanied by global ruptures and small scale rock ejections with concurrent crater formations. The scenario reconciles orbital and physical parameters of the moons. It coherently explains dozens of their properties including spectra, appearances, size differences, crater locations, fracture symmetries, orbits, evolution trends, geologic activity, Phobos’ grooves, mechanism of their origin, etc. The ejective approach is also discussed in the context of observational data on near-Earth asteroids, main belt asteroids Steins, Vesta, and Mars. The approach incorporates known fission mechanism of formation of miniature asteroids, logically accounts for its outliers, and naturally explains formations of small celestial bodies of various sizes. -
Can Moons Have Moons?
A MNRAS 000, 1–?? (2018) Preprint 23 January 2019 Compiled using MNRAS L TEX style file v3.0 Can Moons Have Moons? Juna A. Kollmeier1⋆ & Sean N. Raymond2† 1 Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 2 Laboratoire d’Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, all´eGeoffroy Saint-Hilaire, 33615 Pessac, France Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Each of the giant planets within the Solar System has large moons but none of these moons have their own moons (which we call submoons). By analogy with studies of moons around short-period exoplanets, we investigate the tidal-dynamical stability of submoons. We find that 10 km-scale submoons can only survive around large (1000 km-scale) moons on wide-separation orbits. Tidal dissipation destabilizes the orbits of submoons around moons that are small or too close to their host planet; this is the case for most of the Solar System’s moons. A handful of known moons are, however, capable of hosting long-lived submoons: Saturn’s moons Titan and Iapetus, Jupiter’s moon Callisto, and Earth’s Moon. Based on its inferred mass and orbital separation, the newly-discovered exomoon candidate Kepler-1625b-I can in principle host a large submoon, although its stability depends on a number of unknown parameters. We discuss the possible habitability of submoons and the potential for subsubmoons. The existence, or lack thereof, of submoons, may yield important constraints on satellite formation and evolution in planetary systems. Key words: planets and satellites – exoplanets – tides 1 INTRODUCTION the planet spins quickly or to shrink if the planet spins slowly (e.g. -
Constraints on the Habitability of Extrasolar Moons 3 ¯Glob Its Orbit-Averaged Global Energy flux Fs
Formation, detection, and characterization of extrasolar habitable planets Proceedings IAU Symposium No. 293, 2012 c 2012 International Astronomical Union Nader Haghighipour DOI: 00.0000/X000000000000000X Constraints on the habitability of extrasolar moons Ren´eHeller1 and Rory Barnes2,3 1Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam email: [email protected] 2University of Washington, Dept. of Astronomy, Seattle, WA 98195, USA 3Virtual 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. -
Lecture 12 the Rings and Moons of the Outer Planets October 15, 2018
Lecture 12 The Rings and Moons of the Outer Planets October 15, 2018 1 2 Rings of Outer Planets • Rings are not solid but are fragments of material – Saturn: Ice and ice-coated rock (bright) – Others: Dusty ice, rocky material (dark) • Very thin – Saturn rings ~0.05 km thick! • Rings can have many gaps due to small satellites – Saturn and Uranus 3 Rings of Jupiter •Very thin and made of small, dark particles. 4 Rings of Saturn Flash movie 5 Saturn’s Rings Ring structure in natural color, photographed by Cassini probe July 23, 2004. Click on image for Astronomy Picture of the Day site, or here for JPL information 6 Saturn’s Rings (false color) Photo taken by Voyager 2 on August 17, 1981. Click on image for more information 7 Saturn’s Ring System (Cassini) Mars Mimas Janus Venus Prometheus A B C D F G E Pandora Enceladus Epimetheus Earth Tethys Moon Wikipedia image with annotations On July 19, 2013, in an event celebrated the world over, NASA's Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth. 8 Newly Discovered Saturnian Ring • Nearly invisible ring in the plane of the moon Pheobe’s orbit, tilted 27° from Saturn’s equatorial plane • Discovered by the infrared Spitzer Space Telescope and announced 6 October 2009 • Extends from 128 to 207 Saturnian radii and is about 40 radii thick • Contributes to the two-tone coloring of the moon Iapetus • Click here for more info about the artist’s rendering 9 Rings of Uranus • Uranus -- rings discovered through stellar occultation – Rings block light from star as Uranus moves by. -
Predictable Patterns in Planetary Transit Timing Variations and Transit Duration Variations Due to Exomoons
Astronomy & Astrophysics manuscript no. ms c ESO 2016 June 21, 2016 Predictable patterns in planetary transit timing variations and transit duration variations due to exomoons René Heller1, Michael Hippke2, Ben Placek3, Daniel Angerhausen4, 5, and Eric Agol6, 7 1 Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany; [email protected] 2 Luiter Straße 21b, 47506 Neukirchen-Vluyn, Germany; [email protected] 3 Center for Science and Technology, Schenectady County Community College, Schenectady, NY 12305, USA; [email protected] 4 NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA; [email protected] 5 USRA NASA Postdoctoral Program Fellow, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA 6 Astronomy Department, University of Washington, Seattle, WA 98195, USA; [email protected] 7 NASA Astrobiology Institute’s Virtual Planetary Laboratory, Seattle, WA 98195, USA Received 22 March 2016; Accepted 12 April 2016 ABSTRACT We present new ways to identify single and multiple moons around extrasolar planets using planetary transit timing variations (TTVs) and transit duration variations (TDVs). For planets with one moon, measurements from successive transits exhibit a hitherto unde- scribed pattern in the TTV-TDV diagram, originating from the stroboscopic sampling of the planet’s orbit around the planet–moon barycenter. This pattern is fully determined and analytically predictable after three consecutive transits. The more measurements become available, the more the TTV-TDV diagram approaches an ellipse. For planets with multi-moons in orbital mean motion reso- nance (MMR), like the Galilean moon system, the pattern is much more complex and addressed numerically in this report. -
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). -
The Asteroid Florence 3122
The Asteroid Florence 3122 By Mohammad Hassan BACKGROUND • Asteroid 3122 Florence is a stony trinary asteroid of the Amor group. • It was discovered on March 2nd 1981 by Astronomer Schelte J. ”Bobby” Bus at Siding Spring Observatory. It was named in honor of Florence Nightingdale, the founder of modern nursing. • It has an approximate diameter of 5 kilometers. It also orbits the Sun at a distance of 1.0-2.5 astronomical unit once every 2 years and 4 months (859 days). • Florence rotates once every 2.4 hours, a result that was determined previously from optical measurements of the asteroid’s brightness variations. • THE MOST FASINATING THING IS THAT IT HAS TWO MOONS, HENCE WHY IT IS A PART OF THE AMOR GROUP. • The reason why this Asteroid 3122 Florence is important is because it is a near-earth object with the potential of hitting the earth in the future time. Concerns? • Florence 3122 was classified as a potentially hazardous object because of its minimum orbit intersection distance (less than 0.05 AU). This means that Florence 3122 has the potential to make close approaches to the Earth. • Another thing to keep in mind was that Florence 3122 minimum distance from us was 7 millions of km, about 20 times farthest than our moon. What actually happened? • On September 1st, 2017, Florence passed 0.047237 AU from Earth. That is about 7,000 km or 4,400 miles. • From Earth’s perspective, it brightened to apparent magnitude 8.5. It was also visible in small telescopes for several nights as it moved from south to north through the constellations. -
Exploration of the Planets – 1971
Video Transcript for Archival Research Catalog (ARC) Identifier 649404 Exploration of the Planets – 1971 Narrator: For thousands of years, man observed the rising and setting Sun, the cycle of seasons, the fixed stars, and those he called wanderers, or planets. And from these observations evolved his notions of the universe. The naked eye extended its vision through instruments that saw the craters on the Moon, the changing colors of Mars, and the rings of Saturn. The fantasies, dreams, and visions of space travel became the reality of Apollo. Early in 1970, President Nixon announced the objectives of a balanced space program for the United States that would include the scientific investigation of all the planets in the solar system. Of the nine planets circling the Sun, only the Earth is known to us at firsthand. But observational techniques on Earth and in space have given us some idea of the appearance and movement of the planets. And enable us to depict their physical characteristics in some detail. Mercury, only slightly larger than the Moon, is so close to the Sun that it is difficult to observe by telescope. It is believed to be one large cinder, with no atmosphere and a day-night temperature range of nearly 1,000 degrees. Venus is perpetually cloud-covered. Spacecraft report a surface temperature of 900 degrees Fahrenheit and an atmospheric pressure 100 times greater than Earth’s. We can only guess what the surface is like, possibly a seething netherworld beneath a crushing, poisonous carbon dioxide atmosphere. Of Mars, the Red Planet, we have evidence of its cratered surface, photographed by the Mariner spacecraft. -
Low Velocity Impacts Mars's Inner Moon, Phobos, Is Located Deep In
Phobos: Low Velocity Impacts Mars’s inner moon, Phobos, is located deep in the planet’s gravity well and orbits far below the planet’s synchronous orbit. Images of the surface of Phobos, in particular from Viking Orbiter 1, MGS, MRO, and MEX, reveal a rich collisional history, including fresh‐looking impact craters and subdued older ones, very large impact structures (compared to the size of Phobos), such as Stickney, and much smaller ones. Sources of impactors colliding with Phobos include a priori: A) Impactors from outside the martian system (asteroids, comets, and fragments thereof); B) Impactors from Mars itself (ejecta from large impacts on Mars); and C) Impactors from Mars orbit, including impact ejecta launched from Deimos and ejecta launched from, and reintercepted by, Phobos. In addition to individual craters on Phobos, the networks of grooves on this moon have also been attributed in part or in whole to impactors from some of these sources, particularly B. We report the preliminary results of a systematic survey of the distribution, morphology, albedo, and color characteristics of fresh impact craters and associated ejecta deposits on Phobos. Considering that the different potential impactor sources listed above are expected to display distinct dominant compositions and different characteristic impact velocity regimes, we identify specific craters on Phobos that are more likely the result of low velocity impacts by impactors derived from Mars orbit than from any alternative sources. Our finding supports the hypothesis that the spectrally “Redder Unit” on Phobos may be a superficial veneer of accreted ejecta from Deimos, and that Phobos’s bulk might be distinct in composition from Deimos. -
Journal of Physics Special Topics an Undergraduate Physics Journal
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Leicester Open Journals Journal of Physics Special Topics An undergraduate physics journal P5 1 Conditions for Lunar-stationary Satellites Clear, H; Evan, D; McGilvray, G; Turner, E Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH November 5, 2018 Abstract This paper will explore what size and mass of a Moon-like body would have to be to have a Hill Sphere that would allow for lunar-stationary satellites to exist in a stable orbit. The radius of this body would have to be at least 2500 km, and the mass would have to be at least 2:1 × 1023 kg. Introduction orbital period of 27 days. We can calculate the Geostationary satellites are commonplace orbital radius of the satellite using the following around the Earth. They are useful in provid- equation [3]: ing line of sight over the entire planet, excluding p 3 the polar regions [1]. Due to the Earth's gravi- T = 2π r =GMm; (1) tational influence, lunar-stationary satellites are In equation 1, r is the orbital radius, G is impossible, as the Moon's smaller size means it the gravitational constant, MM is the mass of has a small Hill Sphere [2]. This paper will ex- the Moon, and T is the orbital period. Solving plore how big the Moon would have to be to allow for r gives a radius of around 88000 km. When for lunar-stationary satellites to orbit it.