Zodiacal light

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Two false dawns, gegenschein (middle) and the rest of the zodiacal band of light and zodiac marked (visually crossed by the Milky Way), in this composite image of the night sky above the northern and southern hemisphere Night Sky from Hawai'i and Chile (iotw2225c).jpg
Two false dawns, gegenschein (middle) and the rest of the zodiacal band of light and zodiac marked (visually crossed by the Milky Way), in this composite image of the night sky above the northern and southern hemisphere

Zodiacal light is a faint glow of diffuse light in the sky scattered by interplanetary dust, particularly a zodiacal cloud, along the ecliptic, and therefore the zodiac. It is mostly only visible in very dark conditions across the night sky along the whole ecliptic as the zodiacal band, [2] backscattered slightly brighter from an oval area of the band directly opposite to the light source as the gegenschein (or counterglow) and brightest as a triangle-shaped area at the horizon around the light source as false dawn, mostly just before or after the Sun rises or sets. [3] [4] [5] [6]

Contents

Zodiacal light contributes [7] to the natural light of the sky, though since zodiacal light is very faint, it is often outshined and rendered invisible by moonlight or light pollution.

The interplanetary dust in the Solar System forms a thick, pancake-shaped cloud called the zodiacal cloud which straddles the ecliptic plane. The particle sizes range from 10 to 300 micrometres, implying masses from one nanogram to tens of micrograms. [8] [9]

The Pioneer 10 and Helios spacecraft observations in the 1970s revealed zodiacal light to be scattered by the interplanetary dust cloud in the Solar System. [10] [11] Analysis of images of impact debris from the Juno spacecraft shows that the distribution of the dust extends from Earth's orbit to the 4:1 orbital resonance with Jupiter at 2.06 AU, and suggests that the dust is from Mars. [12] However, no other dedicated dust instrumentation on Pioneer 10 , Pioneer 11 , Galileo , Ulysses , and Cassini found an indication that Mars is a significant source of dust besides comets and asteroids. [10] [13] [14] [15]

Viewing

Zodiacal light seen behind the Submillimeter Array from the summit of Mauna Kea Submillimeter Array Night.jpg
Zodiacal light seen behind the Submillimeter Array from the summit of Mauna Kea

In the mid-latitudes, the zodiacal light is best observed in the western sky in the spring after the evening twilight has completely disappeared, or in the eastern sky in the autumn just before the morning twilight appears. The zodiacal light appears as a column, brighter at the horizon and tilted at the angle of the ecliptic. The light scattered from extremely small dust particles is strongly forward scattering, although the zodiacal light actually extends all the way around the sky, hence it is brightest when observing at a small angle with the Sun. This is why it is most clearly visible near sunrise or sunset when the Sun is blocked, but the dust particles nearest the line of sight to the Sun are not. The dust band that causes the zodiacal light is uniform across the whole ecliptic.

The dust further from the ecliptic is almost undetectable except when viewed at a small angle with the Sun. Thus it is possible to see more of the width at small angles toward the Sun, and it appears wider near the horizon, closer to the Sun under the horizon.

Origin

Moonlight and zodiacal light over La Silla Observatory Moonlight and Zodiacal Light Over La Silla Observatory.jpg
Moonlight and zodiacal light over La Silla Observatory

The source of the dust has been long debated. Until recently, it was thought that the dust originated from the tails of active comets and from collisions between asteroids in the asteroid belt. [17] Many of our meteor showers have no known active comet parent bodies. Over 85 percent of the dust is attributed to occasional fragmentations of Jupiter-family comets that are nearly dormant. [18] Jupiter-family comets have orbital periods of less than 20 years [19] and are considered dormant when not actively outgassing, but may do so in the future. [20] The first fully dynamical model of the zodiacal cloud demonstrated that only if the dust was released in orbits that approach Jupiter, is it stirred up enough to explain the thickness of the zodiacal dust cloud. The dust in meteoroid streams is much larger, 300 to 10,000 micrometres in diameter, and falls apart into smaller zodiacal dust grains over time.

Colorful center of the Milky Way and the zodiacal light above the Very Large Telescope Romantic Sunset over the VLT.jpg
Colorful center of the Milky Way and the zodiacal light above the Very Large Telescope

The Poynting–Robertson effect forces the dust into more circular (but still elongated) orbits, while spiralling slowly into the Sun. Hence a continuous source of new particles is needed to maintain the zodiacal cloud. Cometary dust and dust generated by collisions among the asteroids are believed to be mostly responsible for the maintenance of the dust cloud producing the zodiacal light and the gegenschein.

Particles can be reduced in size by collisions or by space weathering. When ground down to sizes less than 10 micrometres, the grains are removed from the inner Solar System by solar radiation pressure. The dust is then replenished by the infall from comets. Zodiacal dust around nearby stars is called exozodiacal dust; it is a potentially important source of noise in attempts to directly image extrasolar planets. It has been pointed out that this exozodiacal dust, or hot debris disks, can be an indicator of planets, as planets tend to scatter the comets to the inner Solar System.

In 2015, new results from the secondary ion dust spectrometer COSIMA on board the ESA/Rosetta orbiter confirmed that the parent bodies of interplanetary dust are most probably Jupiter-family comets such as comet 67P/Churyumov–Gerasimenko. [22] Data from the Juno mission indicate that the dust close to Earth has a local origin in the inner Solar System, best fitting the planet Mars as a source. [23]

Appearance

Zodiacal light seen from Cerro Paranal Zodiacal Light Seen from Paranal.jpg
Zodiacal light seen from Cerro Paranal
Zodiacal light viewed from the Moon, during Apollo 15 AS15-98-13325.jpg
Zodiacal light viewed from the Moon, during Apollo 15

Zodiacal light is produced by sunlight reflecting off dust particles in the Solar System known as cosmic dust. Consequently, its spectrum is the same as the solar spectrum. The material producing the zodiacal light is located in a lens-shaped volume of space centered on the sun and extending well out beyond the orbit of Earth. This material is known as the interplanetary dust cloud. Since most of the material is located near the plane of the Solar System, the zodiacal light is seen along the ecliptic. The amount of material needed to produce the observed zodiacal light is quite small. If it were in the form of 1 mm particles, each with the same albedo (reflecting power) as the Moon, each particle would be 8 km from its neighbors. The gegenschein may be caused by particles directly opposite the Sun as seen from Earth, which would be in full phase.

According to Nesvorný and Jenniskens, when the dust grains are as small as about 150 micrometres in size, they will hit the Earth at an average speed of 14.5 km/s, many as slowly as 12 km/s. If so, they pointed out, this comet dust can survive entry in partially molten form, accounting for the unusual attributes of the micrometeorites collected in Antarctica, which do not resemble the larger meteorites known to originate from asteroids. In recent years, observations by a variety of spacecraft have shown significant structure in the zodiacal light including dust bands associated with debris from particular asteroid families and several cometary trails.

Cultural significance

According to Alexander von Humboldt's Kosmos , Mesoamericans were aware of the zodiacal light before 1500. [24] It was perhaps first reported in print by Joshua Childrey in 1661. The phenomenon was investigated by the astronomer Giovanni Domenico Cassini in 1683. According to some sources, he explained it by dust particles around the Sun. [25] [26] Other sources state that it was first explained this way by Nicolas Fatio de Duillier, in 1684, [27] whom Cassini advised to study the zodiacal light. [24]

Importance to Islam

The Islamic prophet Muhammad described zodiacal light in reference to the timing of the five daily prayers, calling it the "false dawn" (الفجر الكاذبal-fajr al-kādhib). Muslim oral tradition preserves numerous sayings, or hadith, in which Muhammad describes the difference between the light of false dawn, appearing in the sky long after sunset, and the light of the first band of horizontal light at sunrise, the "true dawn" (الفجر الصادقal-fajr al-sādiq). According to the vast majority of Muslim scholars, astronomical dawn is considered the true dawn. Practitioners of Islam use Muhammad's descriptions of zodiacal light to avoid errors in determining the timing of fasting and daily prayers. [28] [29] [30]

Brian May

In 2007, Brian May, lead guitarist with the band Queen, completed his thesis, A Survey of Radial Velocities in the Zodiacal Dust Cloud, thirty-six years after abandoning it to pursue a career in music. [31] He was able to submit it only because of the minimal amount of research on the topic undertaken during the intervening years. May described the subject as being one that became "trendy" again in the 2000s. [32]

Other planets

First ever panorama image of the dust ring of Venus's orbital space, imaged by Parker Solar Probe Venus dust ring.png
First ever panorama image of the dust ring of Venus's orbital space, imaged by Parker Solar Probe

Other planets, like Venus or Mercury, [33] have shown to have rings of interplanetary dust in their orbital spaces.

See also

Related Research Articles

<span class="mw-page-title-main">Comet</span> Natural object in space that releases gas

A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or coma surrounding the nucleus, and sometimes a tail of gas and dust gas blown out from the coma. These phenomena are due to the effects of solar radiation and the outstreaming solar wind plasma acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently close and bright, a comet may be seen from Earth without the aid of a telescope and can subtend an arc of up to 30° across the sky. Comets have been observed and recorded since ancient times by many cultures and religions.

<span class="mw-page-title-main">Gegenschein</span> Optical effect of interplanetary dust reflections

Gegenschein or counterglow is a faintly bright spot in the night sky centered at the antisolar point. The backscatter of sunlight by interplanetary dust causes this optical phenomenon, being a zodiacal light and part of its zodiacal light band.

<span class="mw-page-title-main">Solar System</span> The Sun and objects orbiting it

The Solar System is the gravitationally bound system of the Sun and the objects that orbit it. It formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc. The Sun is a typical star that maintains a balanced equilibrium by the fusion of hydrogen into helium at its core, releasing this energy from its outer photosphere. Astronomers classify it as a G-type main-sequence star.

<span class="mw-page-title-main">Asteroid belt</span> Region between the orbits of Mars and Jupiter

The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids or minor planets. The identified objects are of many sizes, but much smaller than planets, and, on average, are about one million kilometers apart. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System.

<span class="mw-page-title-main">Meteor shower</span> Celestial event caused by streams of meteoroids entering Earths atmosphere

A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller than a grain of sand, so almost all of them disintegrate and never hit the Earth's surface. Very intense or unusual meteor showers are known as meteor outbursts and meteor storms, which produce at least 1,000 meteors an hour, most notably from the Leonids. The Meteor Data Centre lists over 900 suspected meteor showers of which about 100 are well established. Several organizations point to viewing opportunities on the Internet. NASA maintains a daily map of active meteor showers.

<span class="mw-page-title-main">Micrometeoroid</span> Meteoroid with a mass of less than one gram

A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface.

<span class="mw-page-title-main">Night sky</span> Appearance of the sky in a clear night

The night sky is the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon.

<span class="mw-page-title-main">Interplanetary medium</span> Material which fills the Solar System

The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move. The IPM stops at the heliopause, outside of which the interstellar medium begins. Before 1950, interplanetary space was widely considered to either be an empty vacuum, or consisting of "aether".

<span class="mw-page-title-main">Cosmic dust</span> Dust floating in space

Cosmic dust – also called extraterrestrial dust, space dust, or star dust – is dust that occurs in outer space or has fallen onto Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 μm), such as micrometeoroids and meteoroids. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust, and circumplanetary dust. There are several methods to obtain space dust measurement.

The interplanetary dust cloud, or zodiacal cloud, consists of cosmic dust that pervades the space between planets within planetary systems, such as the Solar System. This system of particles has been studied for many years in order to understand its nature, origin, and relationship to larger bodies. There are several methods to obtain space dust measurement.

Comet dust refers to cosmic dust that originates from a comet. Comet dust can provide clues to comets' origin. When the Earth passes through a comet dust trail, it can produce a meteor shower.

<span class="mw-page-title-main">Small Solar System body</span> Object in the Solar System

A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies'".

<span class="mw-page-title-main">Exozodiacal dust</span> Small particles between exoplanets

Exozodiacal dust is 1–100 micrometre-sized grains of amorphous carbon and silicate dust that fill the plane of extrasolar planetary systems. It is the exoplanetary analog of zodiacal dust, the 1–100 micrometre-sized dust grains observed in the solar system, especially interior to the asteroid belt. As with the zodiacal dust, these grains are probably produced by outgassing comets, as well as by collisions among bigger parent bodies like asteroids. Exozodiacal dust clouds are often components of debris disks that are detected around main-sequence stars through their excess infrared emission. Particularly hot exozodiacal disks are also commonly found near spectral type A-K stars. By convention, exozodiacal dust refers to the innermost and hottest part of these debris disks, within a few astronomical units of the star. How exozodiacal dust is so prevalent this close to stars is a subject of debate with several competing theories attempting to explain the phenomenon. The shapes of exozodiacal dust clouds can show the dynamical influence of extrasolar planets, and potentially indicate the presence of these planets. Because it is often located near a star's habitable zone, exozodiacal dust can be an important noise source for attempts to image terrestrial planets. Around 1 in 100 stars in the nearby solar systems shows a high content of warm dust that is around 1000 times greater than the average dust emission in the 8.5–12 μm range.

This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outside the atmosphere of Earth. The field of astronomy features an extensive vocabulary and a significant amount of jargon.

<span class="mw-page-title-main">Outline of the Solar System</span> Overview of and topical guide to the Solar System

The following outline is provided as an overview of and topical guide to the Solar System:

<span class="mw-page-title-main">Sergei Ipatov</span> Soviet, Russian and American scientist

Sergei Ivanovich Ipatov is a Soviet, Russian, and American scientist, laureate of the F. A. Bredikhin Prize in astronomy of the Russian Academy of Sciences, Doctor of Physical and Mathematical Sciences. Asteroid 14360 Ipatov was named in his honor.

<span class="mw-page-title-main">Space dust measurement</span> Space dust measurements

Space dust measurement refers to the study of small particles of extraterrestrial material, known as micrometeoroids or interplanetary dust particles (IDPs), that are present in the Solar System. These particles are typically of micrometer to sub-millimeter size and are composed of a variety of materials including silicates, metals, and carbon compounds. The study of space dust is important as it provides insight into the composition and evolution of the Solar System, as well as the potential hazards posed by these particles to spacecraft and other space-borne assets. The measurement of space dust requires the use of advanced scientific techniques such as secondary ion mass spectrometry (SIMS), optical and atomic force microscopy (AFM), and laser-induced breakdown spectroscopy (LIBS) to accurately characterize the physical and chemical properties of these particles.

<span class="mw-page-title-main">Helios Dust Instrumentation</span>

The Helios 1 and 2 spacecraft each carried two dust instruments to characterize the Zodiacal dust cloud inside the Earth’s orbit down to spacecraft positions 0.3 AU from the sun. The Zodiacal light instrument measured the brightness of light scattered by interplanetary dust along the line of sight. The in situ Micrometeoroid analyzer recorded impacts of meteoroids onto the sensitive detector surface and characterized their composition. The instruments delivered radial profiles of their measured data. Comet or meteoroid streams, and even interstellar dust were identified in the data.

<span class="mw-page-title-main">Dust astronomy</span> Branch of astronomy

Dust astronomy is a subfield of astronomy that uses the information contained in individual cosmic dust particles ranging from their dynamical state to its isotopic, elemental, molecular, and mineralogical composition in order to obtain information on the astronomical objects occurring in outer space. Dust astronomy overlaps with the fields of Planetary science, Cosmochemistry, and Astrobiology.

References

  1. ↑ "False Dawn". www.eso.org. Retrieved 14 February 2017.
  2. ↑ Darling, David. "Zodiacal cloud". Internet Encyclopedia of Science.
  3. ↑ "APOD: 2012 January 16 - Zodiacal Light and the False Dawn".
  4. ↑ "What are Zodiacal Lights?".
  5. ↑ "EarthSky | Zodiacal light: All you need to know". 6 September 2021.
  6. ↑ Coffey, Rebecca. "In Early March, Look To The West For The Zodiacal Light!". Forbes. Retrieved 2021-06-05.
  7. ↑ Reach, W. T. (1997). "The structured zodiacal light: IRAS, COBE, and ISO observations". Diffuse Infrared Radiation and the Irts. 124: 1. Bibcode:1997ASPC..124...33R.
  8. ↑ Peucker-Ehrenbrink, Bernhard; Schmitz, Birger (2001). Accretion of extraterrestrial matter throughout earth's history. Springer. pp. 66–67. ISBN   978-0-306-46689-2.
  9. ↑ McCracken, C. W. (1967). "Conditions of encounter between dust and the planets". Smithsonian Contributions to Astrophysics. 11: 213. Bibcode:1967SCoA...11..213M.
  10. 1 2 Hanner, M. S. (1976). "Pioneer 10 observations of zodiacal light brightness near the ecliptic: Changes with heliocentric distance". Interplanetary Dust and Zodiacal Light. Lecture Notes in Physics. Vol. 48. pp. 29–35. Bibcode:1976LNP....48...29H. doi:10.1007/3-540-07615-8_448. ISBN   978-3-540-07615-5.
  11. ↑ Leinert, Ch.; Röser, S.; Buitrago, L. (February 1983). "How to maintain the spatial distribution of interplanetary dust". Astronomy and Astrophysics. 118 (2): 345–357. Bibcode:1983A&A...118..345L . Retrieved 28 July 2022.
  12. ↑ Shekhtman, Lonnie (9 March 2021). "Serendipitous Juno Detections Shatter Ideas About Origin of Zodiacal Light". Jet Propulsion Laboratory . NASA. Archived from the original on 18 March 2021. Retrieved 19 March 2021.
  13. ↑ Humes, D. (November 1980). "Results of Pioneer 10 and 11 Meteoroid Experiments: Interplanetary and Near-Saturn". Journal of Geophysical Research. 85 (A11): 5841–5852. Bibcode:1980JGR....85.5841H. doi:10.1029/JA085iA11p05841 . Retrieved 28 July 2022.
  14. ↑ Grün, E.; et al. (October 1997). "South-North and Radial Traverses through the Interplanetary Dust Cloud". Icarus. 129 (2): 270–288. Bibcode:1997Icar..129..270G. doi: 10.1006/icar.1997.5789 .
  15. ↑ Soja, R.H.; Grün, E.; Strub, P.; Sommer, M.; Millinger, M.; Vaubaillon, J.; Alius, W.; Camodeca, G.; Hein, F.; Laskar, J.; Gastieau, M.; Fienga, A.; Schwarzkopf, G.H.; Herzog, J.; Gutschke, K.; Skuppin, N.; Srama, R. (August 2019). "IMEM2: a meteoroid environment model for the inner solar system". Astronomy & Astrophysics. 628 (A109): 13. Bibcode:2019A&A...628A.109S. doi: 10.1051/0004-6361/201834892 . S2CID   199117335 . Retrieved 24 January 2022.
  16. ↑ "Moonlight and Zodiacal Light Over La Silla". ESO Picture of the Week. Retrieved 21 July 2013.
  17. ↑ Espy, Ashley J.; Dermott, S.; Kehoe, T. J. (September 2006). "Towards a Global Model of the Zodiacal Cloud". Bulletin of the American Astronomical Society. 38: 557. Bibcode:2006DPS....38.4101E.
  18. ↑ Nesvorný, David; Jenniskens, Peter; Levison, Harold F.; Bottke, William F.; Vokrouhlický, David; Gounelle, Matthieu (April 20, 2010). "Cometary Origin of the Zodiacal Cloud and Carbonaceous Micrometeorites. Implications for hot debris disks". Astrophysical Journal. 713 (2): 816–836. arXiv: 0909.4322 . Bibcode:2010ApJ...713..816N. doi:10.1088/0004-637x/713/2/816. S2CID   18865066.
  19. ↑ Jenniskens, Petrus Matheus Marie (2006). Meteor showers and their parent comets. Cambridge University Press. p. 108. ISBN   978-0-521-85349-1.
  20. ↑ SPACE.com Staff (6 January 2011). "Comet or Asteroid? Big Space Rock Has Identity Crisis". SPACE.com. Retrieved 23 May 2011. Dormant comets retain some subsurface volatiles and may start outgassing once again as they near the sun.
  21. ↑ "Romantic Sunset over the VLT". www.eso.org. European Southern Observatory . Retrieved 21 April 2015.
  22. ↑ Rita Schulz; et al. (12 February 2015). "Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years". Nature. 518 (7538): 216–218. Bibcode:2015Natur.518..216S. doi:10.1038/nature14159. PMID   25624103. S2CID   205242328.
  23. ↑ Space Daily: Juno data shatter ideas about origin of Zodiacal Light
  24. 1 2 Ley, Willy (April 1961). "The Puzzle Called Gegenschein". For Your Information. Galaxy Science Fiction. pp. 74–84.
  25. ↑ Petrus Matheus Marie Jenniskens (14 September 2006). Meteor Showers and Their Parent Comets. Cambridge University Press. p. 531. ISBN   978-0-521-85349-1.
  26. ↑ Fechtig, H.; Leinert, Ch.; Berg, O. (2001). "Historical Perspectives". Interplanetary Dust. Astronomy and Astrophysics Library. Springer Link. pp. 1–55. doi:10.1007/978-3-642-56428-4_1. ISBN   978-3-642-62647-0 . Retrieved 23 March 2022.
  27. ↑ Steven J. Dick (31 August 2013). Discovery and Classification in Astronomy: Controversy and Consensus. Cambridge University Press. p. 350. ISBN   978-1-107-03361-0.
  28. ↑ Sahih Muslim 1094c – The Book of Fasting – Sunnah.com – Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم)
  29. ↑ "Sahih Moslim (The Authentic Hadiths of Muslim) 1-4 Vol 2: صحيح مسلم 1/4 [عربي/إنكليزي] ج2". January 2011.
  30. ↑ "Distinguishing the True Dawn from the False Dawn (sunnahonline.com)".
  31. ↑ May, Brian (2007). A Survey of Radial Velocities in the Zodiacal Dust Cloud. Springer Nature. Bibcode:2007asor.book.....M. doi:10.1007/978-0-387-77706-1. hdl:10044/1/1333. ISBN   978-0-387-77705-4 . Retrieved 27 May 2017.
  32. ↑ Terri Gross interviews Brian May, National Public Radio show Fresh Air
  33. ↑ Frazier, Sarah (2021-04-16). "NASA's Parker Solar Probe Sees Venus Orbital Dust Ring". NASA. Retrieved 2023-01-21.
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