The heliosphere-interstellar medium interaction: One shock or two?
|
|
- Irma Griffith
- 8 years ago
- Views:
Transcription
1 1 The heliosphere-interstellar medium interaction: One shock or two? John D. Richardson M.I.T. Abstract. The issue of whether a shock forms in the interstellar medium as it approaches the heliopause has not been settled. Observations generally show that the local interstellar medium is slightly supersonic with respect to a stationary (constant distance from the Sun) heliopause. The solar wind dynamic pressure varies over the solar cycle, causing the heliopause distance to move inward and outward. This work shows that the heliopause speeds may be large compared to the speed of the interstellar medium. This leads to the scenario where the interstellar medium is supersonic with respect to the heliopause when the heliopause moves outward (the declining phase of the solar cycle) and subsonic the rest of the time. A shock would form when the heliopause moves outwards and dissipate when the heliopause moves inwards. The heliospheric radio emission is shown to occur at times when the heliopause moves outwards and thus may be related to the formation of the shock in the interstellar medium. This work leads to two testable predictions: 1) the heliospheric radio emissions will intensify when the solar wind pressure increases and 2) the temperature of the interstellar neutrals will fluctuate over a solar cycle with larger temperatures when there is a shock in the interstellar medium.
2 2 Introduction The interaction of the heliosphere with the interstellar medium has engendered much interest of late as the Voyager spacecraft reach distances where crossing of the termination shock may be imminent. In and again in intense heliospheric 2-3 khz radio emissions were observed by Voyager 1 and 2 [Kurth et al., 1984; Gurnett and Kurth, 1993]. One interpretation is that these emissions are triggered by the passage of a strong interplanetary shock through a region near the heliopause [Gurnett et al., 1993]. These emissions are the first direct evidence of the approach to the interstellar medium. Recent work on anomalous cosmic ray gradients provides evidence that the shock location is at roughly AU and that the shock is a weak shock [Stone et al., 1996]. Since the solar wind pressure is expected to decrease as solar maximum approaches [Richardson et al., 1996], the Voyagers may cross the termination shock in the next few years. The impending reconnaissance of this long-postulated boundary and the heliosheath beyond have driven a recent surge in both theoretical modeling of the solar wind - interstellar medium interaction and in efforts to pinpoint the properties of the local interstellar medium. The first models were formulated by Wallis [1971] and Holzer [1972]. Since then increasingly sophisticated Monte Carlo [Baranov and Malama, 1993; 1995] and fluid [Pauls et al., 1995; Zank et al., 1996] models have been developed to self-consistently treat the various neutral and plasma populations. A major question concerning the topology of the solar wind-interstellar medium interaction is whether the interstellar medium is supersonic with respect to the heliopause. Figure 1 shows a schematic picture of the heliospheric interaction with the local interstellar medium; the arrows show plasma flow directions. If the local interstellar medium is supersonic a shock (indicated by the? s) forms upstream of the heliopause, resulting in what is called the twoshock model (the other shock being the termination shock). If the second shock exists, the inflowing local interstellar medium plasma would slow, heat, and become more dense upon crossing this shock. The coupling of the interstellar plasma to the interstellar neutrals would lead to heating of the neutrals as well. Zank et al. [1996] show that a major difference between 1 and 2-shock models is that the 2-shock models predict upstream neutrals will be heated by a factor of 2 over their temperature in the local interstellar medium, whereas the 1-shock model predicts no heating. In theory, observation of the temperatures should discriminate between these models based on temperature, but the observations are not conclusive. Properties of the local interstellar medium have been recently reviewed [Frisch, 1995; Axford, 1996]. The Sun is moving through the local interstellar medium at about 26 km/s. Frisch [1995] estimates the sound speed is on the order of 10 km/s and the magnetosonic velocity km/s, although considerable uncertainty is present in these numbers. (The flow is supersonic if the Mach number M, the ratio of the flow speed to the magnetosonic speed, is greater than 1.) Zank et al. [1996] point out that cosmic ray pressure or a larger magnetic field could, using reasonable parameters, give a subsonic flow. In this paper, we suggest that since the interstellar medium flow is very close to M=1, the movement of the heliopause driven by solar wind dynamic pressure changes can determine whether a 1- or 2-shock topology is present. Since the solar wind dynamic pressure changes over the solar cycle, we can predict when each topology is most likely. Solar Wind Dynamic Pressures and Heliopause Distance The solar wind dynamic pressure varies on time scales of seconds to solar cycles. Since only long-duration changes are likely to affect heliopause motion, we plot 300-day running averages
3 of the solar wind dynamic pressure observed by IMP 8 (dotted line) and Voyager 2 (solid line) in the top panel of Figure 1. The sunspot number is shown in the bottom panel. The solar wind dynamic pressure is a minimum at solar maximum and a maximum in the declining phase of the solar cycle. The IMP 8 increase in pressure is over 50% from 1980 to 1982 and almost 50% from 1991 to The Voyager 2 pressure changes are comparable. Since IMP 8 remains in the same orbit whereas Voyager moves in heliolatitude with time, IMP 8 data should provide a more consistent picture of the change of solar wind pressure with time and are used throughout the rest of this paper. The solar wind will evolve as it moves outward, but, since the averaging times used in this paper are comparable to the transit time of the solar wind through the heliosphere, this evolution should not affect the results. The distance to the heliopause is calculated following Belcher et al. [1993] and using the smoothed IMP 8 pressure profile in Figure 1 to give the instantaneous equilibrium distances shown in Figure 2. Although the heliopause does not instantaneously achieve its equilibrium position, this does give a sense of its motion. For 2-3 years after solar maximum the heliosphere rapidly expands, then follows a slow contraction until the next solar minimum. Figure 3 shows the 300-day average velocities of the heliopause again assuming it remains at its equilibrium position. The heliopause velocities derived in this manner clearly dwarf the 26 km/s speed of the interstellar medium. The actual rate of motion of the termination shock and heliopause in response to changes in solar wind pressure is of course not known, although several models have been used to estimate the speed of the termination shock. Analytical studies of a planar 1-D hydrodynamic shock find the shock can move up to 100 km/s [Barnes, 1993; Naidu and Barnes, 1994]. Whang and Burlaga [1993] found that solar wind pressure changes cause the termination shock to move 14 AU over a solar cycle with speed of up to 100 km/s. The 2-D hydrodynamic model of Karmesin et al. [1995] predicts 15 AU range of termination shock values but an average velocity of only 12 km/s; they use a sinusoidal pressure variation, whereas the observed pressure increase is much faster than this. The best observational analogies are probably the planetary magnetospheres; although much smaller than the termination shock, the bow shocks of the planets presumably respond to solar wind variations in a manner similar to the termination shock. Bow shock motions of km/s are common in response to solar wind pressure changes. Given the uncertainty in how the termination shock will respond, we use the velocities shown in Figure 3 in our discussion of the termination shock and heliopause response to solar wind variations. For the gross effects discussed here, if the response is only half as fast our results will not be affected. The dotted line in Figure 3 shows a reasonable estimate of the difference between the velocity of the local interstellar medium and its magnetosonic velocity (6 km/s). If the heliopause is moving inwards at greater than 6 km/s, then the local interstellar medium is subsonic with respect to the heliopause and a bow shock will not form. If the heliopause is moving inwards less rapidly or moving outwards, then the local interstellar medium is supersonic with respect to the heliopause boundary and a bow shock must form. Figure 3 shows that there are two times when velocities are strongly outward for long periods (1-2 years). The first is from to about , the second is double-peaked and lasts from 1989 to We can estimate when the increase in pressure will affect the heliopause position. If the termination shock is at 80 AU, the pressure increase at must travel about 79 AU at the average solar wind speed of 440 km/s, or roughly 300 days. The heliopause distance is about 110 AU; the speed across this distance depends on the shock strength which recent evidence suggests is 2.4 [Stone et al., 1995]. This would imply an initial post-shock speed of about 150 km/s which would decrease as the heliopause is approached. An average speed from termination shock to heliopause of 100 km/s would give a transit time of 480 days for a total time 3
4 from Earth to the heliopause of 780 days or 2.1 years. After this amount of time the heliopause should begin to accelerate outward. The details of the transition from a one-shock to two-shock heliosphere are beyond the scope of this paper, but some time lag must occur at this step also. When the heliopause begins to move outward the plasma density and temperature across the heliopause will increase, first by compression as the heliopause moves outward, then due to the shock when it forms. One obvious speculation is that the onset of the radio emission could be related to the change in plasma conditions when the heliopause moves outwards. Possibilities are that the emissions come from the vicinity of the shock itself, or that the increased densities and temperatures caused by the outward motion are conducive to generation of the radio emission. Figure 4 shows the spectral density of emission frequency and speed of the heliopause. The outward motion increases sharply to a plateau starting at and the first radio emissions were observed near The second strong outward motion of the heliopause reaches a plateau at , whereas the second radio emission event starts in In each case the time delay is roughly 3.5 years; given the relatively slow sound speeds and large distances between the heliopause and the probable location of an upstream shock an additional 1.5 year lag (compared to the 2-year lag calculated above) is not implausible; MHD modeling is required to better determine the time scales. A current suggestion [Gurnett et al., 1993] is that the passage of very strong interplanetary shocks (observed at the Voyagers in 1981 and 1991 and associated with very large Forbush decreases) through the plasma beyond the heliopause. The radio emissions begin each time about 400 days after the solar wind shock passes Voyager. An advantage of the mechanism proposed here is that it can qualitatively explain the double peak in the radio emissions, which diminish for a few month in early 1993 before intensifying again. The decrease in radio emissions can be interpreted as due to the cessation of outward motion at about , with the intensification of the emissions occurring when the heliopause again moves outwards starting near One prediction of this hypothesis is that the radio emissions will begin roughly 3.5 years after the solar wind pressure begins to increase as the next solar cycle begins. Another prediction is that the temperature of the interstellar neutrals upstream of the heliopause will change over the solar cycle. At times when the heliosphere is expanding, such as the descending phase of the solar cycle, we expect two shocks will be present and thus that the interstellar neutrals will be hotter [Zank et al., 1995]. When the heliosphere is contracting, the local interstellar medium will not be shocked before encountering the heliopause and the interstellar neutrals will be cooler. In the two-shock case, the heating at the shock depends on the strength of the shock; thus we expect variation of interstellar neutral temperature depending on the speed of the heliopause even when there are two shocks. As summarized by [Zank et al., 1995], the temperature of the interstellar neutrals can be measured with current techniques but results are so far inconclusive. 4
5 5 Summary The location of the heliopause is determined by a balance between the solar wind dynamic pressure and the pressure of the interstellar medium. Changes in the solar wind pressure over a solar cycle should cause the heliopause to move; the velocity is probably large enough that the interstellar medium alternates between being subsonic and supersonic with respect to the heliopause. This may result in the formation and dissipation of the heliospheric bow shock over the course of a solar cycle. Since the heliospheric bow shock would heat the plasma when present, the plasma temperature and, through coupling, the neutral temperature should vary, an effect which can be observed from Earth. Acknowledgments. The Voyager plasma wave data was taken from the PWS WWW page. This work was supported by NASA under contract from JPL to MIT (Voyager) and NAGW-1550 (SR&T).
6 6 References Adams, T. F., and P. C. Frisch, High-resolution observations of the Lyman alpha sky background, Astrophys J., 212, 300, Axford, W. I., The heliosphere, Sp. Sci. Rev., 78, 9 14, Baranov, V. B., and Y. G. Malama, Model of the solar wind interaction with the local interstellar medium: Numerical solution of self-consistent problem, J. Geophys. Res., 98, 15,157, Baranov, V. B., and Y. G. Malama, Effect of local interstellar medium H fractional ionization on distant solar wind, J. Geophys. Res., 100, 14,755, Barnes, A., Motion of the heliospheric termination shock, 1, a gas dynamic model, J. Geophys. Res., 98, 15,137, Belcher, J. W., A. J. Lazarus, R. L. McNutt, Jr., and G. S. Gordon, Jr., Solar wind conditions in the outer heliosphere and the distance to the termination shock, J. Geophys. Res., 98, 15,166 15,183, Bertaux, J-.L., R. Lallemont, V. G. Kurt, and E. N. Mironova, Characteristics of the local interstellar hydrogen determined from Prognoz 5 and 6 interplanetary Lyman α line profile measurements with a hydrogen absorption shell, Astron. Astrophys., 150, 1, Clarke, J. T., R. Lallemont, J-.L. Bertaux, E. Quemerais, HST/GHRS observations of the interplanetary medium downwind and in the inner solar system, Astrophys J., 448, 893, Frisch, P. C., Characteristics of nearby interstellar matter, Sp. Sci. Rev., 72, , Gurnett, D. A., and W. S. Kurth, Radio emissions from the outer heliosphere, Sp. Sci. Rev., 78, 53 66, Gurnett, D. A., W. S. Kurth, S. C. Allendorf, and R. L. Poynter, Radio emission from the heliopause triggered by an interplanetary shock, Science, 262, , Holzer, T. E., Interaction of the solar wind with the neutral component of the interstellar gas, J. Geophys. Res., 77, , Karsemin, S. R., P. C. Liewer, and J. U. Brackbill, Motion of the TS in response to an 11 year variation in the solar wind, Geophys. Res. Lett., 22, , Kurth, W. S., D. A. Gurnett, F. L. Scarf, and R. L. Poynter, Detection of a radio emission at 3 khz in the outer heliosphere, Nature, 312, 27-31, Naidu, K., and A. Barnes, Motion of the heliospheric TS, 4, MHD effects, J. Geophys. Res., 89, 17674, Pauls, H.L., G.P. Zank, and L.L. Williams, Interaction of the solar wind with the local interstellar medium, J. Geophys. Res., 100, 21595, Richardson, J. D., J. W. Belcher, A. J. Lazarus, K. I. Paularena, P. R. Gazis, and A. Barnes, Plasmas in the outer heliosphere, Proceedings of the Eighth International Solar Wind Conference, Dana Point, CA, D. Winterhalter, J. T. Gosling, S. R. Habbal, W. S. Kurth, M. Neugebauer, eds., , AIP Conference Proceedings 382, Stone, E. C., A. C. Cummings, and W. R. Webber, The distance to the solar wind termination shock in 1993 and 1994 from observations of anomalous cosmic rays, J. Geophys. Res., 101, 11017, 1996 Wallis, M., Shock-free deceleration of the solar wind, Nature, 233, 23, Zank, G.P., H.L. Pauls, L.L. Williams, and D. Hall, Interaction of the solar wind with the local interstellar medium: A multifluid approach, J. Geophys. Res., 101, 21,639, 1996.
7 7 Figure Captions Fig. 1. A schematic drawing of the configuration of the heliosphere-interstellar medium interaction. The termination shock is where the solar wind becomes subsonic, the heliopause is the boundary between solar wind and interstellar plasma, and the heliospheric bow shock may form if the interstellar plasma is supersonic with respect to the heliopause. Fig. 2. The top panel shows 300-day running averages of the solar wind dynamic pressure observed by IMP 8 (dotted line) and Voyager 2 (solid line, normalized to 1 AU). The bottom panel shows the sunspot number. The pressure increases rapidly just after solar maximum. Fig. 3. The location of the heliopause assuming equilibrium between the solar wind and interstellar medium pressures. Fig. 4. The speed of the heliopause in response to the observed solar wind pressure variations. Fig. 5. The spectral density of radio emission in the Voyager 1 plasma wave subsystem 3.11 khz channel (top panel) and the rate of motion of the heliopause (bottom panel).
8
9
10
11
12
Statistical Study of Magnetic Reconnection in the Solar Wind
WDS'13 Proceedings of Contributed Papers, Part II, 7 12, 2013. ISBN 978-80-7378-251-1 MATFYZPRESS Statistical Study of Magnetic Reconnection in the Solar Wind J. Enžl, L. Přech, J. Šafránková, and Z. Němeček
More informationSolar Wind: Theory. Parker s solar wind theory
Solar Wind: Theory The supersonic outflow of electrically charged particles, mainly electrons and protons from the solar CORONA, is called the SOLAR WIND. The solar wind was described theoretically by
More informationKolmogorov versus Iroshnikov-Kraichnan spectra: Consequences for ion heating in
Kolmogorov versus Iroshnikov-Kraichnan spectra: Consequences for ion heating in the solar wind C. S. Ng 1, A. Bhattacharjee 2, D. Munsi 2, P. A. Isenberg 2, and C. W. Smith 2 1 Geophysical Institute, University
More informationThe Limits of Our Solar System
The Limits of Our Solar System John D. Richardson Massachusetts Institute of Technology Nathan A. Schwadron Boston University Richardson and Schwadron: The Limits of Our Solar System 443 The heliosphere
More informationCoronal expansion and solar wind
Coronal expansion and solar wind The solar corona over the solar cycle Coronal and interplanetary temperatures Coronal expansion and solar wind acceleration Origin of solar wind in magnetic network Multi-fluid
More informationSolar Wind and Pickup Protons
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111,, doi:10.109/005ja011533, 006 A three-dimensional MHD solar wind model with pickup protons A. V. Usmanov 1, and M. L. Goldstein 3 Received
More informationCorrelation of speed and temperature in the solar wind
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111,, doi:10.1029/2006ja011636, 2006 Correlation of speed and temperature in the solar wind W. H. Matthaeus, 1 H. A. Elliott, 2 and D.
More informationWave-particle and wave-wave interactions in the Solar Wind: simulations and observations
Wave-particle and wave-wave interactions in the Solar Wind: simulations and observations Lorenzo Matteini University of Florence, Italy In collaboration with Petr Hellinger, Simone Landi, and Marco Velli
More informationProton and He 2+ Temperature Anisotropies in the Solar Wind Driven by Ion Cyclotron Waves
Chin. J. Astron. Astrophys. Vol. 5 (2005), No. 2, 184 192 (http:/www.chjaa.org) Chinese Journal of Astronomy and Astrophysics Proton and He 2+ Temperature Anisotropies in the Solar Wind Driven by Ion Cyclotron
More informationBulk properties of the slow and fast solar wind and interplanetary coronal mass ejections measured by Ulysses: Three polar orbits of observations
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114,, doi:10.1029/2008ja013631, 2009 Bulk properties of the slow and fast solar wind and interplanetary coronal mass ejections measured
More informationProton temperature and Plasma Volatility
The microstate of the solar wind Radial gradients of kinetic temperatures Velocity distribution functions Ion composition and suprathermal electrons Coulomb collisions in the solar wind Waves and plasma
More informationSolar Wind and the Plasma Structure of an Interinstitutional Satellite
Annu. Rev. Astron. Astrophys. 1989.27:199-234 Copyright 1989 by Annual Reviews Inc. All rights reserved INTERACTION BETWEEN THE SOLAR WIND AND THE INTERSTELLAR MEDIUM Thomas E. Holzer High Altitude Observatory,
More informationThe solar wind (in 90 minutes) Mathew Owens
The solar wind (in 90 minutes) Mathew Owens 5 th Sept 2013 STFC Advanced Summer School m.j.owens@reading.ac.uk Overview There s simply too much to cover in 90 minutes Hope to touch on: Formation of the
More informationTemperature anisotropy in the solar wind
Introduction Observations Simulations Summary in the solar wind Petr Hellinger Institute of Atmospheric Physics & Astronomical Institute AS CR, Prague, Czech Republic Kinetic Instabilities, Plasma Turbulence
More informationSolar cycle. Auringonpilkkusykli. 1844 Heinrich Schwabe: 11 year solar cycle. ~11 years
Sun Solar cycle Auringonpilkkusykli 1844 Heinrich Schwabe: 11 year solar cycle ~11 years Auringonpilkkusykli Solar cycle Butterfly diagram: Edward Maunder 1904 New cycle Spots appear at mid-latitudes Migration
More informationAcceleration of the Solar Wind as a Result of the Reconnection of Open Magnetic Flux with Coronal Loops
Acceleration of the Solar Wind as a Result of the Reconnection of Open Magnetic Flux with Coronal Loops L. A. Fisk 1, G. Gloeckler 1,2, T. H. Zurbuchen 1, J. Geiss 3, and N. A. Schwadron 4 1 Department
More informationIn studying the Milky Way, we have a classic problem of not being able to see the forest for the trees.
In studying the Milky Way, we have a classic problem of not being able to see the forest for the trees. A panoramic painting of the Milky Way as seen from Earth, done by Knut Lundmark in the 1940 s. The
More informationAcceleration of the solar wind as a result of the reconnection of open magnetic flux with coronal loops
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. A4, 1157, doi:10.1029/2002ja009284, 2003 Acceleration of the solar wind as a result of the reconnection of open magnetic flux with coronal loops L. A. Fisk
More informationEVOLUTION OF THE SOLAR WIND PLASMA PARAMETERS FLUCTUATIONS - ULYSSES OBSERVATIONS
EVOLUTION OF THE SOLAR WIND PLASMA PARAMETERS FLUCTUATIONS - ULYSSES OBSERVATIONS NEDELIA ANTONIA POPESCU 1, EMIL POPESCU 2,1 1 Astronomical Institute of Romanian Academy Str. Cutitul de Argint 5, 40557
More informationSolar Wind Heating by MHD Turbulence
Solar Wind Heating by MHD Turbulence C. S. Ng, A. Bhattacharjee, and D. Munsi Space Science Center University of New Hampshire Acknowledgment: P. A. Isenberg Work partially supported by NSF, NASA CMSO
More informationCosmic Structure Formation and Dynamics: Cosmological N-body Simulations of Galaxy Formation and Magnetohydrodynamic Simulations of Solar Atmosphere
Chapter 3 Epoch Making Simulation Cosmic Structure Formation and Dynamics: Cosmological N-body Simulations of Galaxy Formation and Magnetohydrodynamic Simulations of Solar Atmosphere Project Representative
More information165 points. Name Date Period. Column B a. Cepheid variables b. luminosity c. RR Lyrae variables d. Sagittarius e. variable stars
Name Date Period 30 GALAXIES AND THE UNIVERSE SECTION 30.1 The Milky Way Galaxy In your textbook, read about discovering the Milky Way. (20 points) For each item in Column A, write the letter of the matching
More informationSPACE WEATHER INTERPRETING THE WIND. Petra Vanlommel & Luciano Rodriguez
SPACE WEATHER INTERPRETING THE WIND Petra Vanlommel & Luciano Rodriguez THE SUN LOSES ENERGY Radiation Mass Particles THE SUN LOSES ENERGY PHYSICAL REPHRASING Total Solar Irradiance Solar Wind Fast Particles
More informationSolar Energetic Protons
Solar Energetic Protons The Sun is an effective particle accelerator. Solar Energetic Particles (SEPs) are an important hazard to spacecraft systems and constrain human activities in space. Primary radiation
More informationHigh Speed Aerodynamics Prof. K. P. Sinhamahapatra Department of Aerospace Engineering Indian Institute of Technology, Kharagpur
High Speed Aerodynamics Prof. K. P. Sinhamahapatra Department of Aerospace Engineering Indian Institute of Technology, Kharagpur Module No. # 01 Lecture No. # 06 One-dimensional Gas Dynamics (Contd.) We
More informationPROTON IRRADIATION OF CENTAUR, KUIPER BELT, AND OORT CLOUD OBJECTS AT PLASMA TO COSMIC RAY ENERGY
PROTON IRRADIATION OF CENTAUR, KUIPER BELT, AND OORT CLOUD OBJECTS AT PLASMA TO COSMIC RAY ENERGY JOHN F. COOPER Raytheon Technical Services Company LLC, SSDOO Project, NASA Goddard Space Flight Center,
More informationBe Stars. By Carla Morton
Be Stars By Carla Morton Index 1. Stars 2. Spectral types 3. B Stars 4. Be stars 5. Bibliography How stars are formed Stars are composed of gas Hydrogen is the main component of stars. Stars are formed
More informationModeling Galaxy Formation
Galaxy Evolution is the study of how galaxies form and how they change over time. As was the case with we can not observe an individual galaxy evolve but we can observe different galaxies at various stages
More information5. The Nature of Light. Does Light Travel Infinitely Fast? EMR Travels At Finite Speed. EMR: Electric & Magnetic Waves
5. The Nature of Light Light travels in vacuum at 3.0. 10 8 m/s Light is one form of electromagnetic radiation Continuous radiation: Based on temperature Wien s Law & the Stefan-Boltzmann Law Light has
More informationThe Sun and Solar Energy
I The Sun and Solar Energy One of the most important forces behind global change on Earth is over 90 million miles distant from the planet. The Sun is the ultimate, original source of the energy that drives
More informationLecture 10 Formation of the Solar System January 6c, 2014
1 Lecture 10 Formation of the Solar System January 6c, 2014 2 Orbits of the Planets 3 Clues for the Formation of the SS All planets orbit in roughly the same plane about the Sun. All planets orbit in the
More informationThree-dimensional Simulation of Magnetized Cloud Fragmentation Induced by Nonlinear Flows and Ambipolar Diffusion
accepted by Astrophysical Journal Letters Three-dimensional Simulation of Magnetized Cloud Fragmentation Induced by Nonlinear Flows and Ambipolar Diffusion Takahiro Kudoh 1 and Shantanu Basu 2 ABSTRACT
More informationHybrid simulation of ion cyclotron resonance in the solar wind: Evolution of velocity distribution functions
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110,, doi:10.1029/2005ja011030, 2005 Hybrid simulation of ion cyclotron resonance in the solar wind: Evolution of velocity distribution functions Xing Li Institute
More informationSolar Wind Control of Density and Temperature in the Near-Earth Plasma Sheet: WIND-GEOTAIL Collaboration. Abstract
1 Geophys. Res. Letters, 24, 935-938, 1997. Solar Wind Control of Density and Temperature in the Near-Earth Plasma Sheet: WIND-GEOTAIL Collaboration T. Terasawa 1, M. Fujimoto 2, T. Mukai 3, I. Shinohara
More informationThe Solar Wind. Chapter 5. 5.1 Introduction. 5.2 Description
Chapter 5 The Solar Wind 5.1 Introduction The solar wind is a flow of ionized solar plasma and an associated remnant of the solar magnetic field that pervades interplanetary space. It is a result of the
More informationChapter 15.3 Galaxy Evolution
Chapter 15.3 Galaxy Evolution Elliptical Galaxies Spiral Galaxies Irregular Galaxies Are there any connections between the three types of galaxies? How do galaxies form? How do galaxies evolve? P.S. You
More informationLecture 7 Formation of the Solar System. Nebular Theory. Origin of the Solar System. Origin of the Solar System. The Solar Nebula
Origin of the Solar System Lecture 7 Formation of the Solar System Reading: Chapter 9 Quiz#2 Today: Lecture 60 minutes, then quiz 20 minutes. Homework#1 will be returned on Thursday. Our theory must explain
More informationName Class Date. true
Exercises 131 The Falling Apple (page 233) 1 Describe the legend of Newton s discovery that gravity extends throughout the universe According to legend, Newton saw an apple fall from a tree and realized
More information8.1 Radio Emission from Solar System objects
8.1 Radio Emission from Solar System objects 8.1.1 Moon and Terrestrial planets At visible wavelengths all the emission seen from these objects is due to light reflected from the sun. However at radio
More informationThe microstate of the solar wind
The microstate of the solar wind Radial gradients of kinetic temperatures Velocity distribution functions Ion composition and suprathermal electrons Coulomb collisions in the solar wind Waves and plasma
More informationSolar Forcing of Electron and Ion Auroral Inputs
Solar Forcing of Electron and Ion Auroral Inputs Barbara A. Emery (NCAR), Ian G. Richardson (GSFC), David S. Evans (NOAA), Frederick J. Rich (LL/MIT), Gordon Wilson (AFRL), Sarah Gibson (NCAR), Giuliana
More informationThe Layout of the Solar System
The Layout of the Solar System Planets fall into two main categories Terrestrial (i.e. Earth-like) Jovian (i.e. Jupiter-like or gaseous) [~5000 kg/m 3 ] [~1300 kg/m 3 ] What is density? Average density
More informationScience Standard 4 Earth in Space Grade Level Expectations
Science Standard 4 Earth in Space Grade Level Expectations Science Standard 4 Earth in Space Our Solar System is a collection of gravitationally interacting bodies that include Earth and the Moon. Universal
More informationCoronal Heating Problem
Mani Chandra Arnab Dhabal Raziman T V PHY690C Course Project Indian Institute of Technology Kanpur Outline 1 2 3 Source of the energy Mechanism of energy dissipation Proposed mechanisms Regions of the
More informationSpace Weather: An Introduction C. L. Waters. Centre for Space Physics University of Newcastle, Australia
Space Weather: An Introduction C. L. Waters Centre for Space Physics University of Newcastle, Australia 1 Outline Space weather: Conditions on the Sun and in the solar wind, magnetosphere, ionosphere and
More informationCalifornia Standards Grades 9 12 Boardworks 2009 Science Contents Standards Mapping
California Standards Grades 912 Boardworks 2009 Science Contents Standards Mapping Earth Sciences Earth s Place in the Universe 1. Astronomy and planetary exploration reveal the solar system s structure,
More informationGroup Leader: Group Members:
THE SOLAR SYSTEM PROJECT: TOPIC: THE SUN Required Project Content for an Oral/Poster Presentation on THE SUN - What it s made of - Age and how it formed (provide pictures or diagrams) - What is an AU?
More informationJUNJUN LIU MC 131-24 California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 ljj@gps.caltech.edu Phone #: 626-395-8674
JUNJUN LIU MC 131-24 California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 ljj@gps.caltech.edu Phone #: 626-395-8674 Research Interests Comparative planetary climatology, atmospheric
More informationClass 2 Solar System Characteristics Formation Exosolar Planets
Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System
More informationThe unifying field Theory
The unifying field Theory M T Keshe 2000-2009, all rights reserved Date of release 28.10.2009 Abstract In this paper the origin of electromagnetic fields or electromagnetism and how they are created within
More informationL3: The formation of the Solar System
credit: NASA L3: The formation of the Solar System UCL Certificate of astronomy Dr. Ingo Waldmann A stable home The presence of life forms elsewhere in the Universe requires a stable environment where
More informationFrom lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?
From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation? From lowest energy to highest energy, which of the following correctly
More informationSolar Ast ro p h y s ics
Peter V. Foukal Solar Ast ro p h y s ics Second, Revised Edition WI LEY- VCH WILEY-VCH Verlag Co. KCaA Contents Preface 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.1.1 2.1.2 2.2 2.2.1 2.2.2 2.2.3 2.3
More informationCBE 6333, R. Levicky 1 Review of Fluid Mechanics Terminology
CBE 6333, R. Levicky 1 Review of Fluid Mechanics Terminology The Continuum Hypothesis: We will regard macroscopic behavior of fluids as if the fluids are perfectly continuous in structure. In reality,
More informationChapter 8 Welcome to the Solar System
Chapter 8 Welcome to the Solar System 8.1 The Search for Origins What properties of our solar system must a formation theory explain? What theory best explains the features of our solar system? What properties
More informationHeating diagnostics with MHD waves
Heating diagnostics with MHD waves R. Erdélyi & Y. Taroyan Robertus@sheffield.ac.uk SP 2 RC, Department of Applied Mathematics, The University of Sheffield (UK) The solar corona 1860s coronium discovered
More informationUnit 8 Lesson 2 Gravity and the Solar System
Unit 8 Lesson 2 Gravity and the Solar System Gravity What is gravity? Gravity is a force of attraction between objects that is due to their masses and the distances between them. Every object in the universe
More informationSimultaneous Heliospheric Imager and Interplanetary Scintillation observations of CMEs and CIRs
Simultaneous Heliospheric Imager and Interplanetary Scintillation observations of CMEs and CIRs Gareth D. Dorrian (gdd05@aber.ac.uk) 1, Andy R. Breen 1, Jackie A. Davies 2, Alexis P. Rouillard 3, Mario
More informationThe sun and the solar corona
The sun and the solar corona Introduction The Sun of our solar system is a typical star of intermediate size and luminosity. Its radius is about 696000 km, and it rotates with a period that increases with
More informationGraduate Certificate Program in Energy Conversion & Transport Offered by the Department of Mechanical and Aerospace Engineering
Graduate Certificate Program in Energy Conversion & Transport Offered by the Department of Mechanical and Aerospace Engineering Intended Audience: Main Campus Students Distance (online students) Both Purpose:
More informationOn Solar Wind Magnetic Fluctuations and Their Influence on the Transport of Charged Particles in the Heliosphere
On Solar Wind Magnetic Fluctuations and Their Influence on the Transport of Charged Particles in the Heliosphere DISSERTATION zur Erlangung des Grades eines Doktors der Naturwissenschaften in der Fakultät
More informationReceived: 1 June 2007 Revised: 6 November 2007 Accepted: 14 November 2007 Published: 2 January 2008. 1 Introduction
European Geosciences Union 2007 Annales Geophysicae Comparison of magnetic field observations of an average magnetic cloud with a simple force free model: the importance of field compression and expansion
More information8 Radiative Cooling and Heating
8 Radiative Cooling and Heating Reading: Katz et al. 1996, ApJ Supp, 105, 19, section 3 Thoul & Weinberg, 1995, ApJ, 442, 480 Optional reading: Thoul & Weinberg, 1996, ApJ, 465, 608 Weinberg et al., 1997,
More informationHeating & Cooling in Molecular Clouds
Lecture 8: Cloud Stability Heating & Cooling in Molecular Clouds Balance of heating and cooling processes helps to set the temperature in the gas. This then sets the minimum internal pressure in a core
More information1 A Solar System Is Born
CHAPTER 3 1 A Solar System Is Born SECTION Formation of the Solar System BEFORE YOU READ After you read this section, you should be able to answer these questions: What is a nebula? How did our solar system
More informationCHAPTER 6 THE TERRESTRIAL PLANETS
CHAPTER 6 THE TERRESTRIAL PLANETS MULTIPLE CHOICE 1. Which of the following is NOT one of the four stages in the development of a terrestrial planet? 2. That Earth, evidence that Earth differentiated.
More informationUnderstanding Solar Variability as Groundwork for Planet Transit Detection
Stars as Suns: Activity, Evolution, and Planets IAU Symposium, Vol. 219, 2004 A. K. Dupree and A. O. Benz, Eds. Understanding Solar Variability as Groundwork for Planet Transit Detection Andrey D. Seleznyov,
More informationSolar Wind: Global Properties
Solar Wind: Global Properties The most fundamental problem in solar system research is still unsolved: how can the Sun with a surface temperature of only 5800 K heat up its atmosphere to more than a million
More informationastronomy 2008 1. A planet was viewed from Earth for several hours. The diagrams below represent the appearance of the planet at four different times.
1. A planet was viewed from Earth for several hours. The diagrams below represent the appearance of the planet at four different times. 5. If the distance between the Earth and the Sun were increased,
More informationThe Solar Journey: Modeling Features of the Local Bubble and Galactic Environment of the Sun
The Solar Journey: Modeling Features of the Local Bubble and Galactic Environment of the Sun P.C. Frisch and A.J. Hanson Department of Astronomy and Astrophysics University of Chicago and Computer Science
More informationThe Three Heat Transfer Modes in Reflow Soldering
Section 5: Reflow Oven Heat Transfer The Three Heat Transfer Modes in Reflow Soldering There are three different heating modes involved with most SMT reflow processes: conduction, convection, and infrared
More informationSound. References: L.D. Landau & E.M. Lifshitz: Fluid Mechanics, Chapter VIII F. Shu: The Physics of Astrophysics, Vol. 2, Gas Dynamics, Chapter 8
References: Sound L.D. Landau & E.M. Lifshitz: Fluid Mechanics, Chapter VIII F. Shu: The Physics of Astrophysics, Vol., Gas Dynamics, Chapter 8 1 Speed of sound The phenomenon of sound waves is one that
More informationProject Icarus: A Technical Review of the Daedalus Propulsion Configuration and Some Engineering Considerations for the Icarus Vehicle.
Project Icarus: A Technical Review of the Daedalus Propulsion Configuration and Some Engineering Considerations for the Icarus Vehicle. Richard Obousy Ph.D Icarus Project Leader Talk Outline Introduction
More informationThe Main Point. Lecture #34: Solar System Origin II. Chemical Condensation ( Lewis ) Model. How did the solar system form? Reading: Chapter 8.
Lecture #34: Solar System Origin II How did the solar system form? Chemical Condensation ("Lewis") Model. Formation of the Terrestrial Planets. Formation of the Giant Planets. Planetary Evolution. Reading:
More informationChapter 9 Summary and outlook
Chapter 9 Summary and outlook This thesis aimed to address two problems of plasma astrophysics: how are cosmic plasmas isotropized (A 1), and why does the equipartition of the magnetic field energy density
More informationLight as a Wave. The Nature of Light. EM Radiation Spectrum. EM Radiation Spectrum. Electromagnetic Radiation
The Nature of Light Light and other forms of radiation carry information to us from distance astronomical objects Visible light is a subset of a huge spectrum of electromagnetic radiation Maxwell pioneered
More informationChapter 8 Formation of the Solar System Agenda
Chapter 8 Formation of the Solar System Agenda Announce: Mercury Transit Part 2 of Projects due next Thursday Ch. 8 Formation of the Solar System Philip on The Physics of Star Trek Radiometric Dating Lab
More informationData Sets of Climate Science
The 5 Most Important Data Sets of Climate Science Photo: S. Rahmstorf This presentation was prepared on the occasion of the Arctic Expedition for Climate Action, July 2008. Author: Stefan Rahmstorf, Professor
More informationElectric Sailing under Observed Solar Wind Conditions
Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Astrophysics and Space Sciences Transactions Electric Sailing under Observed Solar Wind Conditions P. K. Toivanen
More informationDE2410: Learning Objectives. SOLAR SYSTEM Formation, Evolution and Death. Solar System: To Size Scale. Learning Objectives : This Lecture
DE2410: Learning Objectives SOLAR SYSTEM Formation, Evolution and Death To become aware of our planet, solar system, and the Universe To know about how these objects and structures were formed, are evolving
More informationSummary: Four Major Features of our Solar System
Summary: Four Major Features of our Solar System How did the solar system form? According to the nebular theory, our solar system formed from the gravitational collapse of a giant cloud of interstellar
More informationJustin C. Kasper Harvard-Smithsonian Center for Astrophysics 2012 Heliophysics Summer School Boulder, CO
The Solar Wind Justin C. Kasper Harvard-Smithsonian Center for Astrophysics 2012 Heliophysics Summer School Boulder, CO Goals Origin of the solar wind Historical understanding of the solar wind Why study
More informationLecture L17 - Orbit Transfers and Interplanetary Trajectories
S. Widnall, J. Peraire 16.07 Dynamics Fall 008 Version.0 Lecture L17 - Orbit Transfers and Interplanetary Trajectories In this lecture, we will consider how to transfer from one orbit, to another or to
More informationSolar atmosphere. Solar activity and solar wind. Reading for this week: Chap. 6.2, 6.3, 6.5, 6.7 Homework #2 (posted on website) due Oct.
Solar activity and solar wind Solar atmosphere Reading for this week: Chap. 6.2, 6.3, 6.5, 6.7 Homework #2 (posted on website) due Oct. 17 Photosphere - visible surface of sun. Only ~100 km thick. Features
More informationWELCOME to Aurorae In the Solar System. J.E. Klemaszewski
WELCOME to Aurorae In the Solar System Aurorae in the Solar System Sponsoring Projects Galileo Europa Mission Jupiter System Data Analysis Program ACRIMSAT Supporting Projects Ulysses Project Outer Planets
More informationKinetic physics of the solar wind
"What science do we need to do in the next six years to prepare for Solar Orbiter and Solar Probe Plus?" Kinetic physics of the solar wind Eckart Marsch Max-Planck-Institut für Sonnensystemforschung Complementary
More informationSolar System Overview
Solar System Overview Planets: Four inner planets, Terrestrial planets Four outer planets, Jovian planets Asteroids: Minor planets (planetesimals) Meteroids: Chucks of rocks (smaller than asteroids) (Mercury,
More informationHow Fundamental is the Curvature of Spacetime? A Solar System Test. Abstract
Submitted to the Gravity Research Foundation s 2006 Essay Contest How Fundamental is the Curvature of Spacetime? A Solar System Test Robert J. Nemiroff Abstract Are some paths and interactions immune to
More informationGrade 6 Standard 3 Unit Test A Astronomy. 1. The four inner planets are rocky and small. Which description best fits the next four outer planets?
Grade 6 Standard 3 Unit Test A Astronomy Multiple Choice 1. The four inner planets are rocky and small. Which description best fits the next four outer planets? A. They are also rocky and small. B. They
More informationLecture 14. Introduction to the Sun
Lecture 14 Introduction to the Sun ALMA discovers planets forming in a protoplanetary disc. Open Q: what physics do we learn about the Sun? 1. Energy - nuclear energy - magnetic energy 2. Radiation - continuum
More informationSemester 2. Final Exam Review
Semester 2 Final Exam Review Motion and Force Vocab Motion object changes position relative to a reference point. Speed distance traveled in a period of time. Velocity speed in a direction. Acceleration
More informationChapter 1: Our Place in the Universe. 2005 Pearson Education Inc., publishing as Addison-Wesley
Chapter 1: Our Place in the Universe Topics Our modern view of the universe The scale of the universe Cinema graphic tour of the local universe Spaceship earth 1.1 A Modern View of the Universe Our goals
More informationCluster-II: Scientific Objectives and Data Dissemination
r bulletin 102 may 2000 Cluster-II: Scientific Objectives and Data Dissemination C. Ph. Escoubet Space Science Department, ESA Directorate of Scientific Programmes, ESTEC, Noordwijk, The Netherlands Scientific
More informationGas Dynamics Prof. T. M. Muruganandam Department of Aerospace Engineering Indian Institute of Technology, Madras. Module No - 12 Lecture No - 25
(Refer Slide Time: 00:22) Gas Dynamics Prof. T. M. Muruganandam Department of Aerospace Engineering Indian Institute of Technology, Madras Module No - 12 Lecture No - 25 Prandtl-Meyer Function, Numerical
More informationMHD Modeling of the Interaction Between the Solar Wind and Solar System Objects
554 MHD Modeling of the Interaction Between the Solar Wind and Solar System Objects Andreas Ekenbäck and Mats Holmström Swedish Institute of Space Physics (IRF) P.O. Box 81 98134 Kiruna, Sweden {andreas.ekenback,mats.holmstrom}@irf.se
More informationLecture 23: Terrestrial Worlds in Comparison. This lecture compares and contrasts the properties and evolution of the 5 main terrestrial bodies.
Lecture 23: Terrestrial Worlds in Comparison Astronomy 141 Winter 2012 This lecture compares and contrasts the properties and evolution of the 5 main terrestrial bodies. The small terrestrial planets have
More informationName: Earth 110 Exploration of the Solar System Assignment 1: Celestial Motions and Forces Due in class Tuesday, Jan. 20, 2015
Name: Earth 110 Exploration of the Solar System Assignment 1: Celestial Motions and Forces Due in class Tuesday, Jan. 20, 2015 Why are celestial motions and forces important? They explain the world around
More informationInteraction of Energy and Matter Gravity Measurement: Using Doppler Shifts to Measure Mass Concentration TEACHER GUIDE
Interaction of Energy and Matter Gravity Measurement: Using Doppler Shifts to Measure Mass Concentration TEACHER GUIDE EMR and the Dawn Mission Electromagnetic radiation (EMR) will play a major role in
More informationKinetic effects in the turbulent solar wind: capturing ion physics with a Vlasov code
Kinetic effects in the turbulent solar wind: capturing ion physics with a Vlasov code Francesco Valentini francesco.valentini@fis.unical.it S. Servidio, D. Perrone, O. Pezzi, B. Maruca, F. Califano, W.
More informationCHAPTER 6 INSTRUMENTATION AND MEASUREMENTS 6.1 MEASUREMENTS
CHAPTER 6 INSTRUMENTATION AND MEASUREMENTS 6.1 MEASUREMENTS Atmospheric electricity is a field that is very easy to get into because it does not require a large capital investment for measuring equipment.
More information