Interplanetary_dust_cloud

# Interplanetary dust cloud  **Microsim — three.js (Wikitube framework):** *Interplanetary dust in the Solar System explorer* <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/solar/Solar_System.html?obj=dust&embed=1" data-title="Interplanetary dust in the Solar System explorer"></div> *The Solar System explorer locked on this article's state (`?obj=dust`); every object and population of the [[PORTAL_Solar_System|Solar System portal]] has its own state in the same scene.*  *Try: drag to an edge-on view and see the dust points gather into a thick lens around the plane of the planets; press o to hide the orbits and pick out the separate stream of points strung along Comet Encke's path; set the speed to 1 month/s and watch Earth come round, once a year, to the stretch of that stream that gives the Southern Taurids.* The **interplanetary dust cloud**, also called the zodiacal cloud, is the thin haze of small solid particles that fills the space between the planets of the [[PORTAL_Solar_System|Solar System]], concentrated toward the [[Ecliptic|ecliptic]] and toward the [[Sun]].[^eurekalert2019] Seen from [[Earth]], sunlight scattered by it is the [[Zodiacal_light|zodiacal light]], a faint glow along the zodiac best seen in a dark, moonless sky after evening or before morning twilight. The grains also absorb sunlight and re-emit it in the infrared, and near Earth's orbit the grains that dominate that emission are typically 10–100 micrometres across.[^backman1998] For all its extent the cloud holds little matter. Its total mass is estimated at about 3.5 × 10¹⁶ kg, equal to a single asteroid some 15 km in radius at a density of 2.5 g/cm³.[^pavlov1999] Because sunlight removes grains within thousands to hundreds of thousands of years, the cloud has to be resupplied constantly, mainly by [[Comet|comets]], with smaller shares from colliding [[Asteroid|asteroids]] and from grains entering from interstellar space.[^nesvorny2010] Its particles are studied in three ways: through the light they scatter and emit, by detectors on spacecraft that count the impacts of individual grains, and in the laboratory, after aircraft collect them from the [[Stratosphere|stratosphere]]. The explorer at the top of this page shows the cloud as a field of dust points filling the inner Solar System, with a denser stream along the orbit of Comet Encke. ## Origin Several sources feed the cloud: collisions among asteroids, dust released by active comets, collisions in the [[Kuiper_belt|Kuiper belt]], and grains from the [[Interstellar_medium|interstellar medium]] that stream through the Solar System.[^backman1998] How much each contributes was argued over for decades. The strongest argument for comets is the cloud's shape: it is thick, extending well above and below the ecliptic, and asteroid dust, released on low-inclination orbits, is not stirred up enough to account for it. A dynamical model by David Nesvorný and colleagues found that the thickness is matched only if most of the dust starts on orbits that bring it close to [[Jupiter]], and attributed more than 85% of the cloud to the occasional break-up of nearly dormant Jupiter-family comets.[^nesvorny2010] A proposal from 2021 argues for an additional source. The Juno spacecraft, on its way to Jupiter, recorded dust striking its solar panels, seen by its star cameras as debris knocked off by each impact, and the pattern of hits between Earth and the asteroid belt led John Leif Jørgensen and colleagues to propose that dust from [[Mars]], lifted by its dust storms and escaping its gravity, contributes to the zodiacal light.[^jorgensen2021][^nasa-juno2021] The idea is debated, and the cometary model remains the most widely used. Interstellar grains are a small but measurable part. The Ulysses spacecraft detected grains arriving from the direction of the Sun's motion through the local interstellar gas, with speeds showing that they were not bound to the Sun.[^grun1993] Farther out, dust from collisions in the Kuiper belt is expected to dominate, and the New Horizons dust counter has recorded more of it than models predicted.[^doner2024] ## Life cycle of a particle A dust grain in orbit about the Sun is removed in one of several ways: radiation pressure can push it out of the Solar System, Poynting–Robertson drag can spiral it into the Sun, the [[Solar_wind|solar wind]] adds its own drag and, since grains are electrically charged, magnetic forces; the grain can also sublimate near the Sun, be broken by collisions, or be deflected by the planets.[^backman1998][^burns1979] The strength of sunlight on a grain is measured by β, the ratio of radiation force to the Sun's [[Gravity|gravity]]. Both fall with the square of distance, so β depends only on the grain: for a grain of radius s and density ρ that absorbs all the light that falls on it, β ≈ 5.7 × 10⁻⁴ kg m⁻² / (ρs).[^burns1979] A grain released from a body on a circular orbit escapes if β exceeds 0.5. For ρ = 2,500 kg/m³ that happens below a radius of about 0.5 micrometres, a mass near 10⁻¹² g (derived). Such grains, driven outward by radiation pressure, are known as beta meteoroids, and are generally lighter than about 1.4 × 10⁻¹² g.[^genesis] Larger grains stay bound but lose [[Angular_momentum|angular momentum]], because a moving grain meets sunlight slightly head-on and re-radiates it evenly. The resulting inspiral time from a circular orbit at r astronomical units is about 400 r²/β years.[^burns1979] A 10-micrometre grain with the same density has β ≈ 0.023 and falls from 1 AU into the Sun in about 17,000 years; a 100-micrometre grain takes about ten times longer (derived). Both times are tiny beside the 4.6 billion-year age of the Solar System, so the grains present now were released recently from larger bodies. By one estimate, 99.9% of the Solar System's zodiacal dust is such later-generation dust and 0.1% interstellar; none survives from the [[Protoplanetary_disk|protoplanetary disc]] itself.[^backman1998] The same reasoning shows that dust around a star older than about 10 million years must come from recent collisions or comets rather than leftover disc material.[^backman1998] ## Cloud structures The cloud is not smooth. Infrared maps, above all from the IRAS and COBE satellites, show several kinds of structure on top of a broad, lens-shaped background. Dust trails are narrow streams of large grains following the orbits of short-period comets, the source of many [[Meteor_shower|meteor showers]] when Earth crosses them.[^backman1998] Dust bands are pairs of faint ridges above and below the ecliptic, made by grains from collisions within families of asteroids in the [[Asteroid_belt|asteroid belt]]; the grains keep their parents' orbital inclination while their nodes spread out, so they fill two latitudes rather than one. William Reach and colleagues traced the strongest bands to the Themis, Koronis and Eos families, and weaker bands to other families.[^reach1997] Resonant rings form where grains spiralling inward are caught in mean-motion [[Resonance|resonance]] with a planet and linger near its orbit. A. A. Jackson and Herbert Zook predicted such a ring shepherded by Earth, and Stanley Dermott and colleagues found it in IRAS data in 1994: a band of asteroidal dust near 1 AU with a gap at Earth's position and a denser clump trailing behind the planet.[^jackson1989][^dermott1994] The explorer draws only the broad cloud and the Encke stream. The points are ILLUSTRATIVE, a sample standing in for a population no catalogue could list, while the planets move on JPL orbital elements.[^jpl-t1] ### Rings of dust Rings have now been found at the inner planets too. Images from the STEREO spacecraft revealed a faint ring near the orbit of [[Mercury_(planet)|Mercury]], and data from the Helios probes and from STEREO showed one along the orbit of [[Venus]].[^stenborg2018][^garner2019] The Venus ring was a puzzle, because dust spiralling in from farther out should not settle there in the observed amount. Petr Pokorný and Marc Kuchner proposed in 2019 that a still undetected population of asteroids sharing Venus's orbit supplies it.[^pokorny2019] In 2021 the Parker Solar Probe imaged the Venus ring along its full circumference for the first time.[^rehm2021] ## Dust collection on Earth Fred Whipple showed in 1950 that particles smaller than about 100 micrometres could be slowed by the thin upper atmosphere gently enough to avoid melting, and so could reach the ground nearly intact.[^whipple1950] Laboratory work on such grains began in the 1970s, when Donald Brownlee and co-workers flew collectors on balloons and then on U-2 aircraft in the stratosphere.[^brownlee1977] Some of the recovered grains resembled material from known meteorites. Others were different: porous aggregates of tiny mineral grains with an unequilibrated composition close to the average of the Solar System's non-volatile elements, which suggested that they had formed from fine dust and ice of the kind expected in comets.[^fraundorf1982][^walker1986] Two tests established that the grains came from space. Noble gases implanted by the solar wind were found in them in 1981, and tracks left by energetic particles from solar flares in 1984; neither could arise in grains formed on Earth.[^hudson1981][^bradley1984] NASA's Johnson Space Center set up a programme to collect and curate these particles, and it continues to distribute them to researchers.[^jsc-dust] Together with the presolar grains extracted from meteorites, stratospheric dust is one of the few kinds of extraterrestrial material that laboratories can analyse directly without a sample-return mission. The Apollo samples added a record of their own: microscopic craters on lunar rocks preserve the sizes of grains that struck the [[Moon]].[^morrison1979] Eberhard Grün and colleagues combined such data with spacecraft counts into a standard model of the dust flux at 1 AU across sizes from nanometres to millimetres.[^grun1985] ## Experiments Spacecraft sample the cloud directly, either by measuring the brightness of scattered light from outside Earth's orbit or by counting grain impacts. Pioneer 10 measured the zodiacal light on its way to Jupiter in the early 1970s and found that its brightness fell with distance from the Sun, which tied the light to the dust in the inner Solar System.[^hanner1976] Impact detectors followed. Helios, Pioneer 10 and Pioneer 11 carried them in the 1970s. The Galileo orbiter carried a dust detector to Jupiter, and a near-identical instrument on Ulysses, which travelled out to Jupiter's distance and over the Sun's poles, found streams of fine dust from Jupiter's system and the interstellar grains already mentioned.[^grun1992][^grun1993] The Cassini Cosmic Dust Analyzer measured the charge, speed, mass and composition of grains around Saturn and in interplanetary space.[^srama2004] New Horizons carries the Venetia Burney Student Dust Counter, built by students at the University of Colorado, which counts grains too small for its cameras to see.[^horanyi2008] Beyond 50 AU it has recorded more dust than models predicted, possibly from collisions in the Kuiper belt.[^doner2024] Juno's star cameras, not built as dust detectors, supplied the impact record behind the Mars hypothesis described above.[^jorgensen2021] ## Obscuring effect Seen from anywhere in the inner Solar System, the zodiacal light lies in front of every distant source, including the [[Milky_Way|Milky Way]] and the galaxies beyond it. It therefore hides the extragalactic background light, the faint combined glow of all galaxies, which is much fainter. Measuring that background from near Earth means subtracting a foreground model that is uncertain by more than the signal, and proposals for an interstellar probe cite escape from the zodiacal cloud as one reason to observe from far out.[^brandt2023] New Horizons has already done so. From 42–51 AU, where scattered sunlight from dust is negligible, Tod Lauer and colleagues measured the cosmic optical background with its long-range imager and found a level roughly twice that expected from counts of known galaxies.[^lauer2021] The same obscuration affects the search for planets around other stars, where the dust clouds of other planetary systems, called exozodiacal dust, add a glow that can hide an Earth-like planet.[^backman1998] ## Major review collections Three collections of review chapters mark the development of the field. *Cosmic Dust*, edited by J. A. M. McDonnell and published in 1978, gathered chapters on comets, the zodiacal light as a tracer of interplanetary dust, meteors, interstellar dust, the sampling of microparticles, and their study by instruments on spacecraft, together with impact erosion of the Moon and planets, particle dynamics, and the laboratory acceleration techniques used to simulate micrometeoroid impacts.[^mcdonnell1978] *Interplanetary Dust*, edited by Eberhard Grün, Bo Gustafson, Stanley Dermott and Hugo Fechtig in 2001, reviewed the subject after the IRAS and COBE surveys and the Galileo and Ulysses dust measurements. Its chapters range from history and cometary dust through collected samples, in situ measurement and modelling of the zodiacal cloud to optical properties, orbital evolution, dust around planets, and interstellar and circumstellar dust.[^grun2001] *Cosmic Dust from the Laboratory to the Stars*, edited by Rafael Rodrigo and colleagues and published in 2019 from reviews in *Space Science Reviews*, covers dust from planetary atmospheres and airless bodies through interplanetary dust, meteoroids, comet dust and the plumes of active moons, to interstellar dust and protoplanetary discs, and compares the methods used to study it: in situ detection, remote observation, laboratory experiment, modelling and returned samples.[^rodrigo2019] ## See also - [[Zodiacal_light]] · [[Meteoroid]] · [[Meteor_shower]] - [[Interstellar_medium]] · [[Protoplanetary_disk]] - Cosmic dust · exozodiacal dust · micrometeoroid ## References [^eurekalert2019]: NASA Goddard Space Flight Center (12 March 2019). "What scientists found after sifting through dust in the solar system". *EurekAlert!*. https://www.eurekalert.org/pub_releases/2019-03/nsfc-wsf031219.php [^backman1998]: Backman, D. E.; Caroff, L. J.; Sandford, S. A.; Wooden, D. H. (eds.) (1998). *Exozodiacal Dust Workshop* (Ames Research Center, 1997). NASA Conference Publication NASA/CP-1998-10155. [^pavlov1999]: Pavlov, A. A.; Pavlov, A. K.; Kasting, J. F. (1999). "Irradiated interplanetary dust particles as a possible solution for the deuterium/hydrogen paradox of Earth's oceans". *Journal of Geophysical Research: Planets* 104: 30725–30728. https://doi.org/10.1029/1999JE001120 [^nesvorny2010]: Nesvorný, D.; Jenniskens, P.; Levison, H. F.; Bottke, W. F.; Vokrouhlický, D.; Gounelle, M. (2010). "Cometary origin of the zodiacal cloud and carbonaceous micrometeorites. Implications for hot debris disks". *The Astrophysical Journal* 713: 816–836. https://doi.org/10.1088/0004-637X/713/2/816 [^jorgensen2021]: Jorgensen, J. L.; Benn, M.; Connerney, J. E. P.; Denver, T.; Jorgensen, P. S.; Andersen, A. C.; Bolton, S. J. (2021). "Distribution of interplanetary dust detected by the Juno spacecraft and its contribution to the zodiacal light". *Journal of Geophysical Research: Planets* 126: e2020JE006509. https://doi.org/10.1029/2020JE006509 [^nasa-juno2021]: Shekhtman, S. (8 March 2021). "Serendipitous Juno detections shatter ideas about zodiacal light". NASA. https://www.nasa.gov/feature/goddard/2021/serendipitous-juno-spacecraft-detections-shatter-ideas-about-origin-of-zodiacal-light [^grun1993]: Grün, E.; Zook, H. A.; Baguhl, M.; Balogh, A.; Bame, S. J.; Fechtig, H.; et al. (1993). "Discovery of Jovian dust streams and interstellar grains by the Ulysses spacecraft". *Nature* 362: 428–430. https://doi.org/10.1038/362428a0 [^doner2024]: Doner, A.; Horányi, M.; Bagenal, F.; Brandt, P.; et al. (2024). "New Horizons Venetia Burney Student Dust Counter observes higher than expected fluxes approaching 60 au". *The Astrophysical Journal Letters* 961: L38. https://doi.org/10.3847/2041-8213/ad18b0 [^burns1979]: Burns, J. A.; Lamy, P. L.; Soter, S. (1979). "Radiation forces on small particles in the solar system". *Icarus* 40: 1–48. https://doi.org/10.1016/0019-1035(79)90050-2 [^genesis]: Genesis Discovery 5 Mission (Caltech). "Micrometeorite background". http://www.gps.caltech.edu/genesis/DocumentN.html#BeMe [^reach1997]: Reach, W. T.; Franz, B. A.; Weiland, J. L. (1997). "The three-dimensional structure of the zodiacal dust bands". *Icarus* 127: 461–484. https://doi.org/10.1006/icar.1997.5704 [^jackson1989]: Jackson, A. A.; Zook, H. A. (1989). "A Solar System dust ring with the Earth as its shepherd". *Nature* 337: 629–631. https://doi.org/10.1038/337629a0 [^dermott1994]: Dermott, S. F.; Jayaraman, S.; Xu, Y. L.; Gustafson, B. Å. S.; Liou, J. C. (1994). "A circumsolar ring of asteroidal dust in resonant lock with the Earth". *Nature* 369: 719–723. https://doi.org/10.1038/369719a0 [^jpl-t1]: JPL Solar System Dynamics. "Approximate Positions of the Planets", Table 1. https://ssd.jpl.nasa.gov/planets/approx_pos.html [^stenborg2018]: Stenborg, G.; Stauffer, J. R.; Howard, R. A. (2018). "Evidence for a circumsolar dust ring near Mercury's orbit". *The Astrophysical Journal* 868: 74. https://doi.org/10.3847/1538-4357/aae6cb [^garner2019]: Garner, R. (12 March 2019). "What scientists found after sifting through dust in the solar system". NASA. http://www.nasa.gov/feature/goddard/2019/what-scientists-found-after-sifting-through-dust-in-the-solar-system [^pokorny2019]: Pokorný, P.; Kuchner, M. (2019). "Co-orbital asteroids as the source of Venus's zodiacal dust ring". *The Astrophysical Journal Letters* 873: L16. https://doi.org/10.3847/2041-8213/ab0827 [^rehm2021]: Rehm, J. (15 April 2021). "Parker Solar Probe captures first complete view of Venus orbital dust ring". Johns Hopkins University Applied Physics Laboratory. https://www.jhuapl.edu/NewsStory/210415-Parker-Solar-Probe-sees-Venus-dust-ring/ [^whipple1950]: Whipple, F. L. (1950). "The theory of micro-meteorites. Part I. In an isothermal atmosphere". *Proceedings of the National Academy of Sciences* 36: 687–695. https://doi.org/10.1073/pnas.36.12.687 [^brownlee1977]: Brownlee, D. E. (1978). "Interplanetary dust: possible implications for comets and presolar interstellar grains". In Gehrels, T. (ed.), *Protostars and Planets*. University of Arizona Press, pp. 134–150. Bibcode 1978prpl.conf..134B. [^fraundorf1982]: Fraundorf, P.; Brownlee, D. E.; Walker, R. M. (1982). "Laboratory studies of interplanetary dust". In Wilkening, L. L. (ed.), *Comets*. University of Arizona Press, pp. 383–409. [^walker1986]: Walker, R. M. (1986). "Laboratory studies of interplanetary dust". NASA Conference Publication 2403, p. 55. Bibcode 1986NASCP2403...55W. [^hudson1981]: Hudson, B.; Flynn, G. J.; Fraundorf, P.; Hohenberg, C. M.; Shirck, J. (1981). "Noble gases in stratospheric dust particles: confirmation of extraterrestrial origin". *Science* 211: 383–386. https://doi.org/10.1126/science.211.4480.383 [^bradley1984]: Bradley, J. P.; Brownlee, D. E.; Fraundorf, P. (1984). "Discovery of nuclear tracks in interplanetary dust". *Science* 226: 1432–1434. https://doi.org/10.1126/science.226.4681.1432 [^jsc-dust]: NASA Johnson Space Center, Astromaterials Acquisition and Curation Office. "Cosmic Dust". http://curator.jsc.nasa.gov/dust/ [^morrison1979]: Morrison, D. A.; Clanton, U. S. (1979). "Properties of microcraters and cosmic dust of less than 1000 Å dimensions". *Proceedings of the 10th Lunar and Planetary Science Conference* 2: 1649–1663. https://ui.adsabs.harvard.edu/abs/1979LPSC...10.1649M/abstract [^grun1985]: Grün, E.; Zook, H. A.; Fechtig, H.; Giese, R. H. (1985). "Collisional balance of the meteoritic complex". *Icarus* 62: 244–272. https://doi.org/10.1016/0019-1035(85)90121-6 [^hanner1976]: Hanner, M. S.; Sparrow, J. G.; Weinberg, J. L.; Beeson, D. E. (1976). "Pioneer 10 observations of zodiacal light brightness near the ecliptic: changes with heliocentric distance". In *Interplanetary Dust and Zodiacal Light*, Lecture Notes in Physics 48: 29–35. Springer. https://doi.org/10.1007/3-540-07615-8_448 [^grun1992]: Grün, E.; Fechtig, H.; Hanner, M. S.; Kissel, J.; Lindblad, B.-A.; Linkert, D.; Maas, D.; Morfill, G. E.; Zook, H. A. (1992). "The Galileo dust detector". *Space Science Reviews* 60: 317–340. https://doi.org/10.1007/BF00216860 [^srama2004]: Srama, R.; Ahrens, T. J.; Altobelli, N.; Auer, S.; et al. (2004). "The Cassini Cosmic Dust Analyzer". *Space Science Reviews* 114: 465–518. https://doi.org/10.1007/s11214-004-1435-z [^horanyi2008]: Horányi, M.; Hoxie, V.; James, D.; Poppe, A.; Bryant, C.; Grogan, B.; et al. (2008). "The Student Dust Counter on the New Horizons mission". *Space Science Reviews* 140: 387–402. https://doi.org/10.1007/s11214-007-9250-y [^brandt2023]: Brandt, P. C.; Provornikova, E.; Bale, S. D.; Cocoros, A.; DeMajistre, R.; Dialynas, K.; et al. (2023). "Future exploration of the outer heliosphere and very local interstellar medium by Interstellar Probe". *Space Science Reviews* 219: 18. https://doi.org/10.1007/s11214-022-00943-x [^lauer2021]: Lauer, T. R.; Postman, M.; Weaver, H. A.; Spencer, J. R.; Stern, S. A.; et al. (2021). "New Horizons observations of the cosmic optical background". *The Astrophysical Journal* 906: 77. https://doi.org/10.3847/1538-4357/abc881 [^mcdonnell1978]: McDonnell, J. A. M. (ed.) (1978). *Cosmic Dust*. John Wiley & Sons. ISBN 0-471-99512-6. https://ui.adsabs.harvard.edu/abs/1978codu.book.....M/abstract [^grun2001]: Grün, E.; Gustafson, B. Å. S.; Dermott, S.; Fechtig, H. (eds.) (2001). *Interplanetary Dust*. Astronomy and Astrophysics Library, Springer. https://doi.org/10.1007/978-3-642-56428-4 [^rodrigo2019]: Rodrigo, R.; Blum, J.; Hsu, H.-W.; Koschny, D. V.; Levasseur-Regourd, A.-C.; Martín-Pintado, J.; Sterken, V. J.; Westphal, A. (eds.) (2019). *Cosmic Dust from the Laboratory to the Stars*. Space Sciences Series of ISSI, Springer. ISBN 978-94-024-2009-8. https://link.springer.com/book/9789402420098 ## Further reading - Backman, D. E.; et al. (eds.) (1998). *Exozodiacal Dust Workshop*. NASA/CP-1998-10155 (NASA panel report on extrasolar zodiacal emission). - Grün, E.; et al. (eds.) (2001). *Interplanetary Dust*. Springer. https://doi.org/10.1007/978-3-642-56428-4 - NASA Johnson Space Center: Cosmic Dust Laboratory. https://curator.jsc.nasa.gov/dust/ ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Interplanetary_dust_cloud) : [Wikitube](https://en.wikitube.io/wiki/Interplanetary_dust_cloud) · pinned revision [1372526410](https://en.wikipedia.org/w/index.php?oldid=1372526410) · 2026-09-18 ## Previous hub tags Hubs: `Life_Physics`. Portals: [[PORTAL_Solar_System]]. --- *Solar System portal child articles, wave 1 · 2026-09-18 · drafted · row SOL-081 · explorer state `?obj=dust`.*