Zodiacal light

Two false dawns,[1] 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

The zodiacal light (also called false dawn[2][3][4][5] when seen before sunrise) is a faint glow of diffuse sunlight scattered by interplanetary dust. Brighter around the Sun, it appears in a particularly dark night sky to extend from the Sun's direction in a roughly triangular shape along the zodiac, and appears with less intensity and visibility along the whole ecliptic as the zodiacal band.[6] Zodiacal light spans the entire sky and contributes[7] to the natural light of a clear and moonless night sky. A related phenomenon is gegenschein (or counterglow), sunlight backscattered from the interplanetary dust, which appears directly opposite to the Sun as a faint but slightly brighter oval glow.

Zodiacal light contributes[8] 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.[9][10]

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.[11][12] 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.[13] 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.[11][14][15][16]

  1. ^ "False Dawn". www.eso.org. Retrieved 14 February 2017.
  2. ^ "APOD: 2012 January 16 - Zodiacal Light and the False Dawn".
  3. ^ "What are Zodiacal Lights?".
  4. ^ "EarthSky | Zodiacal light: All you need to know". 6 September 2021.
  5. ^ Coffey, Rebecca. "In Early March, Look To The West For The Zodiacal Light!". Forbes. Retrieved 2021-06-05.
  6. ^ Darling, David. "Zodiacal cloud". Internet Encyclopedia of Science.
  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. ^ 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.
  9. ^ Peucker-Ehrenbrink, Bernhard; Schmitz, Birger (2001). Accretion of extraterrestrial matter throughout earth's history. Springer. pp. 66–67. ISBN 978-0-306-46689-2.
  10. ^ McCracken, C. W. (1967). "Conditions of encounter between dust and the planets". Smithsonian Contributions to Astrophysics. 11: 213. Bibcode:1967SCoA...11..213M.
  11. ^ a b 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.
  12. ^ 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.
  13. ^ 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.
  14. ^ 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.
  15. ^ 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.
  16. ^ 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.