Physical Properties of the Local Interstellar Medium
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Science Objectives May Be Summarized As Follows
MAGNETOSPHERE IMAGING INSTRUMENT (MIMI) 9 ON THE CASSINI MISSION TO SATURN/TITAN 2. Scientific Objectives MIMI science objectives may be summarized as follows: Saturn • Determine the global configuration and dynamics of hot plasma in the magneto- sphere of Saturn through energetic neutral particle imaging of ring current, radia- tion belts, and neutral clouds. • Study the sources of plasmas and energetic ions through in situ measurements of energetic ion composition, spectra, charge state, and angular distributions. • Search for, monitor, and analyze magnetospheric substorm-like activity at Saturn. • Determine through the imaging and composition studies the magnetosphere– satellite interactions at Saturn and understand the formation of clouds of neutral hydrogen, nitrogen, and water products. •Investigate the modification of satellite surfaces and atmospheres through plasma and radiation bombardment. • Study Titan’s cometary interaction with Saturn’s magnetosphere (and the solar wind) via high-resolution imaging and in situ ion and electron measurements. • Measure the high energy (Ee > 1 MeV, Ep > 15 MeV) particle component in the inner (L < 5 RS) magnetosphere to assess cosmic ray albedo neutron decay (CRAND) source characteristics. •Investigate the absorption of energetic ions and electrons by the satellites and rings in order to determine particle losses and diffusion processes within the mag- netosphere. • Study magnetosphere–ionosphere coupling through remote sensing of aurora and in situ measurements of precipitating energetic ions and electrons. Jupiter • Study ring current(s), plasma sheet, and neutral clouds in the magnetosphere and magnetotail of Jupiter during Cassini flyby, using global imaging and in situ mea- surements. S. M. KRIMIGIS ET AL. 10 Interplanetary • Determine elemental and isotopic composition of local interstellar medium through measurements of interstellar pickup ions. -
Upon Reconstructing the Origin of the Local Bubble and Loop I Via Radioisotopic Signatures on Earth
galaxies Conference Report A Way Out of the Bubble Trouble?—Upon Reconstructing the Origin of the Local Bubble and Loop I via Radioisotopic Signatures on Earth Michael Mathias Schulreich 1,* ID , Dieter Breitschwerdt 1, Jenny Feige 1 and Christian Dettbarn 2 1 Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany; [email protected] (D.B.); [email protected] (J.F.) 2 Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12–14, 69120 Heidelberg, Germany; [email protected] * Correspondence: [email protected] Received: 31 January 2018; Accepted: 22 February 2018; Published: 25 February 2018 Abstract: Deep-sea archives all over the world show an enhanced concentration of the radionuclide 60Fe, isolated in layers dating from about 2.2 Myr ago. Since this comparatively long-lived isotope is not naturally produced on Earth, such an enhancement can only be attributed to extraterrestrial sources, particularly one or several nearby supernovae in the recent past. It has been speculated that these supernovae might have been involved in the formation of the Local Superbubble, our Galactic habitat. Here, we summarize our efforts in giving a quantitative evidence for this scenario. Besides analytical calculations, we present results from high-resolution hydrodynamical simulations of the Local Superbubble and its presumptive neighbor Loop I in different environments, including a self-consistently evolved supernova-driven interstellar medium. For the superbubble modeling, the time sequence and locations of the generating core-collapse supernova explosions are taken into account, which are derived from the mass spectrum of the perished members of certain, carefully preselected stellar moving groups. -
Science Fiction Stories with Good Astronomy & Physics
Science Fiction Stories with Good Astronomy & Physics: A Topical Index Compiled by Andrew Fraknoi (U. of San Francisco, Fromm Institute) Version 7 (2019) © copyright 2019 by Andrew Fraknoi. All rights reserved. Permission to use for any non-profit educational purpose, such as distribution in a classroom, is hereby granted. For any other use, please contact the author. (e-mail: fraknoi {at} fhda {dot} edu) This is a selective list of some short stories and novels that use reasonably accurate science and can be used for teaching or reinforcing astronomy or physics concepts. The titles of short stories are given in quotation marks; only short stories that have been published in book form or are available free on the Web are included. While one book source is given for each short story, note that some of the stories can be found in other collections as well. (See the Internet Speculative Fiction Database, cited at the end, for an easy way to find all the places a particular story has been published.) The author welcomes suggestions for additions to this list, especially if your favorite story with good science is left out. Gregory Benford Octavia Butler Geoff Landis J. Craig Wheeler TOPICS COVERED: Anti-matter Light & Radiation Solar System Archaeoastronomy Mars Space Flight Asteroids Mercury Space Travel Astronomers Meteorites Star Clusters Black Holes Moon Stars Comets Neptune Sun Cosmology Neutrinos Supernovae Dark Matter Neutron Stars Telescopes Exoplanets Physics, Particle Thermodynamics Galaxies Pluto Time Galaxy, The Quantum Mechanics Uranus Gravitational Lenses Quasars Venus Impacts Relativity, Special Interstellar Matter Saturn (and its Moons) Story Collections Jupiter (and its Moons) Science (in general) Life Elsewhere SETI Useful Websites 1 Anti-matter Davies, Paul Fireball. -
What Lies Immediately Outside of the Heliosphere in the Very Local Interstellar Medium (VLISM): What Will ISP Detect?
EPSC Abstracts Vol. 14, EPSC2020-68, 2020 https://doi.org/10.5194/epsc2020-68 Europlanet Science Congress 2020 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. What lies immediately outside of the heliosphere in the very local interstellar medium (VLISM): What will ISP detect? Jeffrey Linsky1 and Seth Redfield2 1University of Colorado, JILA, Boulder CO, United States of America ([email protected]) 2Wesleyan University, Astronomy Department, Middletown CT, United States of America ([email protected]) The Interstellar Probe (ISP) will provide the first direct measurements of interstellar gas and dust when it travels far beyond the heliopause where the solar wind no longer influences the ambient medium. We summarize in this presentation what we have been learning about the VLISM from 20 years of remote observations with the high-resolution spectrographs on the Hubble Space Telescope. Radial velocity measurements of interstellar absorption lines seen in the lines of sight to nearby stars allow us to measure the kinematics of gas flows in the VLISM. We find that the heliosphere is passing through a cluster of warm partially ionized interstellar clouds. The heliosphere is now at the edge of the Local Interstellar Cloud (LIC) and heading in the direction of the slighly cooler G cloud. Two other warm clouds (Blue and Aql) are very close to the heliosphere. We find that there is a large region of the sky with very low neutral hydrogen column density, which we call the hydrogen hole. In the direction of the hydrogen hole is the brightest photoionizing source, the star Epsilon Canis Majoris (CMa). -
Arxiv:Astro-Ph/9910429V1 22 Oct 1999 Hr Title: Short Chicag of University Astrophysics, and Astronomy of Department Frisch C
1 The galactic environment of the Sun Priscilla C. Frisch 1 Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois Short title: GALACTIC ENVIRONMENT OF THE SUN arXiv:astro-ph/9910429v1 22 Oct 1999 2 Abstract. The interstellar cloud surrounding the solar system regulates the galactic environment of the Sun and constrains the physical characteristics of the interplanetary medium. This paper compares interstellar dust grain properties observed within the solar system with dust properties inferred from observations of the cloud surrounding the solar system. Properties of diffuse clouds in the solar vicinity are discussed to gain insight into the properties of the diffuse cloud complex flowing past the Sun. Evidence is presented for changes in the galactic environment of the Sun within the next 104–106 years. The combined history of changes in the interstellar environment of the Sun, and solar activity cycles, will be recorded in the variability of the ratio of large- to medium-sized interstellar dust grains deposited onto geologically inert surfaces. Combining data from lunar core samples in the inner and outer solar system will assist in disentangling these two effects. 3 1. Introduction The interstellar cloud surrounding the solar system regulates the galactic environment of the Sun and constrains the physical characteristics of the interplanetary medium enveloping the planets. In addition, the daughter products of the interaction between the solar wind and the interstellar cloud surrounding the solar system, when compared with astronomical data, provide a unique window on the chemical evolution of our galactic neighborhood, reveal the fundamental processes that link the interplanetary environment to the galactic environment of the Sun, and constrain the history and physical properties of one sample of a diffuse interstellar cloud. -
Solar System
Solar System From Wikipedia, the free encyclopedia This article is about the Sun and its planetary system. For other systems, see planetary system and star system. Solar System The Sun and planets of the Solar System. Sizes are to scale, distances and illumination are not. Age 4.568 billion years Location Local Interstellar Cloud, Local Bubble, Orion–Cygnus Arm, Milky Way System mass 1.0014 solar masses Nearest star Proxima Centauri (4.22 ly), Alpha Centauri system (4.37 ly) Nearest Alpha Centauri system (4.37 ly) knownplanetary system Planetary system Semi-major axis 30.10 AU (4.503 billion km) of outer planet (Neptune) Distance 50 AU to Kuiper cliff No. of stars 1 Sun No. of planets 8 Mercury, Venus, Earth, Mars,Jupiter, Saturn, Uranus, Neptune No. of Possibly several hundred.[1] known dwarf 5 (Ceres, Pluto, Haumea,Makemake, Eris) are currently planets recognized by the IAU No. of 422 (173 of planets[2] and 249 of minor planets[3]) known natural satellites No. of 628,057 (as of 2013-12-12)[4] known minor planets No. of 3,244 (as of 2013-12-12)[4] known comets No. of 19 identified round satellites Orbit about the Galactic Center Inclination 60.19° (ecliptic) ofinvariable plane to thegalactic plane Distance to 27,000±1,000 ly Galactic Center Orbital speed 220 km/s Orbital period 225–250 Myr Star-related properties Spectral type G2V [5] Frost line ≈5 AU Distance ≈120 AU toheliopause Hill ≈1–2 ly sphere radius The Solar System[a] is the Sun and the objects that orbit the Sun. -
Solar Wind Charge Exchange Contributions to the Diffuse X-Ray Emission
Solar Wind Charge Exchange Contributions to the Diffuse X-Ray Emission T. E. Cravensa, I. P. Robertsona, S. Snowdenb, K. Kuntzc, M. Collierb and M. Medvedeva aDept. of Physics and Astronomy, Malott Hall, 1251 Wescoe Hall Dr., University of Kansas, Lawrence, KS 66045 USA bNASA Goddard Space Flight Center, Greenbelt, MD, 20771 USA cDept. of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 N. Charles St., Baltimore, MD 21218 USA Abstract: Astrophysical x-ray emission is typically associated with hot collisional plasmas, such as the million degree gas residing in the solar corona or in supernova remnants. However, x-rays can also be produced in cooler gas by charge exchange collisions between highly-charged ions and neutral atoms or molecules. This mechanism produces soft x-ray emission plasma when the solar wind interacts with neutral gas in the solar system. Examples of such x-ray sources include comets, the terrestrial magnetosheath, and the heliosphere (where the solar wind interacts with incoming interstellar neutral gas). Heliospheric emission is thought to make a significant contribution to the observed soft x-ray background (SXRB). This emission needs to be better understood so that it can be distinguished from the SXRB emission associated with hot interstellar gas and the galactic halo. Keywords: x-rays, charge exchange, local bubble, heliosphere, solar wind PACS: 95.85 Nv; 96.60 Vg; 96.50 Ci; 96.50 Zc INTRODUCTION A key diagnostic tool for hot astrophysical plasmas is x-ray emission [e.g., 1]. Hot plasmas produce x-rays collisionally, both in the continuum from free-free and bound- free (e.g., electron-ion recombination) transitions and as line emission from highly ionized species (bound-bound transitions). -
Interstellar Heliospheric Probe/Heliospheric Boundary Explorer Mission—A Mission to the Outermost Boundaries of the Solar System
Exp Astron (2009) 24:9–46 DOI 10.1007/s10686-008-9134-5 ORIGINAL ARTICLE Interstellar heliospheric probe/heliospheric boundary explorer mission—a mission to the outermost boundaries of the solar system Robert F. Wimmer-Schweingruber · Ralph McNutt · Nathan A. Schwadron · Priscilla C. Frisch · Mike Gruntman · Peter Wurz · Eino Valtonen · The IHP/HEX Team Received: 29 November 2007 / Accepted: 11 December 2008 / Published online: 10 March 2009 © Springer Science + Business Media B.V. 2009 Abstract The Sun, driving a supersonic solar wind, cuts out of the local interstellar medium a giant plasma bubble, the heliosphere. ESA, jointly with NASA, has had an important role in the development of our current under- standing of the Suns immediate neighborhood. Ulysses is the only spacecraft exploring the third, out-of-ecliptic dimension, while SOHO has allowed us to better understand the influence of the Sun and to image the glow of The IHP/HEX Team. See list at end of paper. R. F. Wimmer-Schweingruber (B) Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, Leibnizstr. 11, 24098 Kiel, Germany e-mail: [email protected] R. McNutt Applied Physics Laboratory, John’s Hopkins University, Laurel, MD, USA N. A. Schwadron Department of Astronomy, Boston University, Boston, MA, USA P. C. Frisch University of Chicago, Chicago, USA M. Gruntman University of Southern California, Los Angeles, USA P. Wurz Physikalisches Institut, University of Bern, Bern, Switzerland E. Valtonen University of Turku, Turku, Finland 10 Exp Astron (2009) 24:9–46 interstellar matter in the heliosphere. Voyager 1 has recently encountered the innermost boundary of this plasma bubble, the termination shock, and is returning exciting yet puzzling data of this remote region. -
A Review of Local Interstellar Medium Properties of Relevance for Space Missions to the Nearest Stars
Project Icarus: A Review of Local Interstellar Medium Properties of Relevance for Space Missions to the Nearest Stars (Accepted for publication in Acta Astronautica) Ian A. Crawford* Department of Earth and Planetary Sciences, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK *Tel: +44 207 679 3431; Email: [email protected] Abstract I review those properties of the interstellar medium within 15 light-years of the Sun which will be relevant for the planning of future rapid (v ≥ 0.1c) interstellar space missions to the nearest stars. As the detailed properties of the local interstellar medium (LISM) may only become apparent after interstellar probes have been able to make in situ measurements, the first such probes will have to be designed conservatively with respect to what can be learned about the LISM from the immediate environment of the Solar System. It follows that studies of interstellar vehicles should assume the lowest plausible density when considering braking devices which rely on transferring momentum from the vehicle to the surrounding medium, but the highest plausible densities when considering possible damage caused by impact of the vehicle with interstellar material. Some suggestions for working values of these parameters are provided. This paper is a submission of the Project Icarus Study Group. Keywords: Interstellar medium; Interstellar travel 1 Introduction The growing realisation that planets are common companions of stars [1,2] has reinvigorated astronautical studies of how they might be explored using interstellar space probes. The history of Solar System exploration to-date shows us that spacecraft are required for the detailed study of planets, and it seems clear that we will eventually require spacecraft to make in situ studies of other planetary systems as well. -
Presence of Interstellar Dust Inside the Earth\'S Orbit
A&A 448, 243–252 (2006) Astronomy DOI: 10.1051/0004-6361:20053909 & c ESO 2006 Astrophysics A new look into the Helios dust experiment data: presence of interstellar dust inside the Earth’s orbit N. Altobelli1,E.Grün12, and M. Landgraf3 1 MPI für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany e-mail: [email protected] 2 HIGP, University of Hawaii, Honolulu, USA e-mail: [email protected] 3 ESA/ESOC, Germany e-mail: [email protected] Received 25 July 2005 / Accepted 21 October 2005 ABSTRACT An analysis of the Helios in situ dust data for interstellar dust (ISD) is presented in this work. Recent in situ dust measurements with impact ionization detectors on-board various spacecraft (Ulysses, Galileo,andCassini) showed the deep penetration of an ISD stream into the Solar System. The Helios dust data provide a unique opportunity to monitor and study the ISD stream alteration at very close heliocentric distances. This work completes therefore the comprehensive picture of the ISD stream properties within the heliosphere. In particular, we show that grav- itation focusing facilitates the detection of big ISD grains (micrometer-size), while radiation pressure prevents smaller grains from penetrating into the innermost regions of the Solar System. A flux value of about 2.6±0.3×10−6 m−2 s−1 is derived for micrometer-size grains. A mean radia- tion pressure-to-gravitation ratio (so-called β ratio) value of 0.4 is derived for the grains, assuming spheres of astronomical silicates to modelize the grains surface optical properties. -