Selected topics

Band astronomy

Jupiter is imaged with the Stockholm Infrared Camera (SIRCA) in the H2O band. Credit: M. Gålfalk, G. Olofsson and H.-G. Florén, Nordic Observatory Telescope (NOT).

At the right is a significant observation of Jupiter in the H2O band using the Stockholm Infrared Camera (SIRCA) on the Nordic Observatory Telescope (NOT).

The image clearly shows that water vapor is plentiful in the Jovian atmosphere.


  • Diameter: 142,900 km (11.2 x Earth's diameter)
  • Length of Day: 9h 55m 30s
  • Length of year: 11.867 years (4334.3 days)
  • Average distance from the Sun: 5.2028 AU (7.783 x 108 km)
  • Average orbital velocity: 13.06 km/s.
  • Average Density: 1.34g/cm3
  • Mass: 1.899 x 1027 kg (317.83 x Earth's Mass).

Jupiter has an equatorial radius of 71,492 ±4 km, a polar radius of 66,854 ±10 km, and a mean radius of 69,911 ± 6 km.[1]


  1. P. Kenneth Seidelmann, B. A. Archinal, M. F. A'hearn, A. Conrad, G. J. Consolmagno, D. Hestroffer, J. L. Hilton, G. A. Krasinsky, G. Neumann (2007). "Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements: 2006". Celestial Mechanics and Dynamical Astronomy 98 (3): 155-80. doi:10.1007/s10569-007-9072-y. 

Object astronomy

This false-color view of Jupiter was taken by the Hubble Space Telescope in 2006. Credit: NASA, ESA, I. de Pater and M. Wong (University of California, Berkeley).

"[T]he ancients’ religions and mythology speak for their knowledge of Uranus; the dynasty of gods had Uranus followed by Saturn, and the latter by Jupiter."[1]

"This false-color view of Jupiter [on the right] was taken by the Hubble Space Telescope in 2006. The red color traces high-altitude haze blankets in the polar regions, equatorial zone, the Great Red Spot, and a second red spot below and to the left of its larger cousin. The smaller red spot is approximately as wide as Earth."[2]

"NASA's Hubble Space Telescope is giving astronomers their most detailed view yet of a second red spot emerging on Jupiter. For the first time in history, astronomers have witnessed the birth of a new red spot on the giant planet, which is located half a billion miles away. The storm is roughly one-half the diameter of its bigger and legendary cousin, the Great Red Spot. Researchers suggest that the new spot may be related to a possible major climate change in Jupiter's atmosphere. These images were taken with Hubble's Advanced Camera for Surveys on April 8 and 16, 2006."[2]


  1. Immanuel Velikovsky. Uranus. The Immanuel Velikovsky Archive. Retrieved 2013-01-14.
  2. 2.0 2.1 I. de Pater and M. Wong (4 May 2006). Hubble Snaps Baby Pictures of Jupiter's "Red Spot Jr.". Baltimore, Maryland USA: HubbleSite. Retrieved 2017-02-12.


The familiar banded appearance of Jupiter gradually gives way to a more mottled appearance closer to the north pole. Credit: NASA/JPL/University of Arizona.
Jupiter's northern half (its northern hemisphere) is shown, from pole to equator, in this map produced from images taken by the Cassini spacecraft in 2000. Credit: NASA/JPL/Space Science Institute.
Jupiter's southern half (its southern hemisphere) is shown, from pole to equator, in this map produced from images taken by the Cassini spacecraft in 2000. Credit: NASA/JPL/Space Science Institute.
This image shows Jupiter's south pole, as seen by NASA's Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). Credit: NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles.{{free media}}

"The familiar banded appearance of Jupiter gradually gives way to a more mottled appearance closer to the north pole in this true color image [on the right] taken in 2000 by NASA's Cassini spacecraft."[1]

"The intricate structures seen in the polar region are clouds of different chemical composition, height and thickness. Clouds are organized by winds, and the mottled appearance in the polar regions suggests more vortex-type motion and winds of less vigor at higher latitudes."[1]

"One possible contributor is that the horizontal component of the Coriolis force, which arises from the planet's rotation and is responsible for curving the trajectories of ocean currents and winds on Earth, has its greatest effect at high latitudes and vanishes at the equator. This tends to create small, intense vortices at high latitudes on Jupiter. Another possibility may lie in that fact that Jupiter overall emits nearly as much of its own heat as it absorbs from the Sun, and this internal heat flux is very likely greater at the poles. This condition could lead to enhanced convection at the poles and more vortex-type structures."[1]

"The resolution here is 114 kilometers (71 miles) per pixel. This contrast-enhanced, edge-sharpened frame was composited from images take at different wavelengths with Cassini's narrow-angle camera, from a distance of 19 million kilometers (11.8 million miles). The spacecraft was in almost a direct line between the Sun and Jupiter, so the solar illumination on Jupiter is almost full phase."[1]

"These color maps [second down on the right] of Jupiter were constructed from images taken by the narrow-angle camera onboard NASA's Cassini spacecraft on Dec. 11 and 12, 2000, as the spacecraft neared Jupiter during its flyby of the giant planet. Cassini was on its way to Saturn. They are the most detailed global color maps of Jupiter ever produced. The smallest visible features are about 120 kilometers (75 miles) across."[2]

"The maps are composed of 36 images: a pair of images covering Jupiter's northern and southern hemispheres was acquired in two colors every hour for nine hours as Jupiter rotated beneath the spacecraft. Although the raw images are in just two colors, 750 nanometers (near-infrared) and 451 nanometers (blue), the map's colors are close to those the human eye would see when gazing at Jupiter."[2]

"The maps show a variety of colorful cloud features, including parallel reddish-brown and white bands, the Great Red Spot, multi-lobed chaotic regions, white ovals and many small vortices. Many clouds appear in streaks and waves due to continual stretching and folding by Jupiter's winds and turbulence. The bluish-gray features along the north edge of the central bright band are equatorial "hot spots," meteorological systems such as the one entered by NASA's Galileo probe. Small bright spots within the orange band north of the equator are lightning-bearing thunderstorms. The polar regions are less clearly visible because Cassini viewed them at an angle and through thicker atmospheric haze (such as the whitish material in the south polar map) [third down on the right]."[2]

"This image [on the left] shows Jupiter's south pole, as seen by NASA's Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection."[3]


  1. 1.0 1.1 1.2 1.3 Sue Lavoie (13 December 2000). PIA02856: High Latitude Mottling on Jupiter. Pasadena, California USA: NASA/JPL. Retrieved 2017-02-12.
  2. 2.0 2.1 2.2 Sue Lavoie (27 March 2006). PIA07783: Cassini's Best Maps of Jupiter (North Polar Map). PIA07783: Cassini's Best Maps of Jupiter (North Polar Map): NASA/JPL. Retrieved 2017-02-12.CS1 maint: location (link)
  3. Betsy Asher Hall and Gervasio Robles (25 May 2017). PIA21641: Southern Storms. Pasadena, California USA: NASA/JPL. Retrieved 2017-07-10.

Trojan asteroids

Diagram of Lagrange points is in a system where the primary is much more massive than the secondary. Credit: Cmglee.

Def. "the L4 and L5 Lagrange points of the Sun-Jupiter orbital configuration"[1] are called the Trojan points.

Def. "an asteroid occupying the Trojan points of the Sun-Jupiter system"[2] is called a Trojan asteroid.


  1. (11 December 2010). Trojan point. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-08-31.
  2. (11 December 2010). Trojan asteroid. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-08-31.





"Field-aligned equatorial electron beams [have been] observed within Jupiter’s middle magnetosphere. ... the Jupiter equatorial electron beams are spatially and/or temporally structured (down to <20 km at auroral altitudes, or less than several minutes), with regions of intense beams intermixed with regions absent of such beams."[1]

"Jovian electrons, both at Jupiter and in the interplanetary medium near Earth, have a very hard spectrum that varies as a power law with energy (see, e.g., Mewaldt et al. 1976). This spectral character is sufficiently distinct from the much softer solar and magnetospheric electron spectra that it has been used as a spectral filter to separate Jovian electrons from other sources ... A second Jovian electron characteristic is that such electrons in the interplanetary medium tend to consist of flux increases of several days duration which recur with 27 day periodicities ... A third feature of Jovian electrons at 1 AU is that the flux increases exhibit a long-term modulation of 13 months which is the synodic period of Jupiter as viewed from Earth".[2]


  1. Jovian electrons are at a maximum irradiating the Sun at solar activity maximum.
  2. Venusian electrons are at a maximum irradiating the Sun at solar activity maximum per the conjunction with Jupiter at periapsis.


  1. Barry H. Mauk and Joachim Saur (October 26, 2007). "Equatorial electron beams and auroral structuring at Jupiter". Journal of Geophysical Research 112 (A10221): 20. doi:10.1029/2007JA012370. http://www.agu.org/journals/ja/ja0710/2007JA012370/figures.shtml. Retrieved 2012-06-02. 
  2. C. T. Russell, D. N. Baker and J. A. Slavin (January 1, 1988). Faith Vilas, Clark R. Chapman, Mildred Shapley Matthews (ed.). The Magnetosphere of Mercury, In: Mercury (PDF). Tucson, Arizona, United States of America: University of Arizona Press. pp. 514–61. Bibcode:1988merc.book..514R. ISBN 0816510857. Retrieved 2012-08-23.CS1 maint: multiple names: editors list (link)


Jupiter entered a position in the sky known as opposition: almost directly opposite the Sun from Earth. Credit: NASA, ESA, A. Simon (Goddard Space Flight Center) and M.H. Wong (University of California, Berkeley).{{fairuse}}

"This new Hubble Space Telescope view of Jupiter, taken on June 27, 2019, [image on the right] reveals the giant planet's trademark Great Red Spot, and a more intense color palette in the clouds swirling in Jupiter's turbulent atmosphere than seen in previous years."[1]

"Hubble's Wide Field Camera 3 observed Jupiter when the planet was 400 million miles from Earth, when Jupiter was near "opposition" or almost directly opposite the Sun in the sky."[1]

"At the time of observation, Jupiter was 4.30AU (400 million miles or 645 million kilometers) from Earth. The semi-major axis of Jupiter's orbit about the Sun is 5.2 astronomical units (483 million miles or 778 million km)."[1]

"The new image was taken in visible light as part of the Outer Planets Atmospheres Legacy program, or OPAL. The program provides yearly Hubble global views of the outer planets to look for changes in their storms, winds, and clouds."[1]

"These images are a composite of separate exposures acquired by the WFC3 instrument on the Hubble Space Telescope. Several filters were used to sample narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: F395N (395 nm); Green: F502N (502 nm); and Red: F631N (631 nm)."[1]

"A worm-shaped feature located below the Great Red Spot is a cyclone, a vortex around a low-pressure area with winds spinning in the opposite direction from the Red Spot. Researchers have observed cyclones with a wide variety of different appearances across the planet. The two white oval-shaped features are anticyclones, like small versions of the Great Red Spot."[1]

The "color of the wide band at the equator [the] bright orange [...] may be a sign that deeper clouds are starting to clear out, emphasizing red particles in the overlying haze."[1]

"The Great Red Spot is a towering structure shaped like a wedding cake, whose upper haze layer extends more than 3 miles (5 kilometers) higher than clouds in other areas. The gigantic structure, with a diameter slightly larger than Earth's, is a high-pressure wind system called an anticyclone that has been slowly downsizing since the 1800s. The reason for this change in size is still unknown."[1]

"On the opposite side of the planet, the band of deep red color northeast of the Great Red Spot and the bright white band to the southeast of it become much fainter. The swirling filaments seen around the outer edge of the red super storm are high-altitude clouds that are being pulled in and around it."[1]

"All of Jupiter's colorful cloud bands in this image are confined to the north and south by jet streams that remain constant, even when the bands change color. The bands are all separated by winds that can reach speeds of up to 400 miles (644 kilometers) per hour."[1]

"Among the most striking features in the image are the rich colors of the clouds moving toward the Great Red Spot, a storm rolling counterclockwise between two bands of clouds. These two cloud bands, above and below the Great Red Spot, are moving in opposite directions. The red band above and to the right (northeast) of the Great Red Spot contains clouds moving westward and around the north of the giant tempest. The white clouds to the left (southwest) of the storm are moving eastward to the south of the spot."[1]

"The bands are created by differences in the thickness and height of the ammonia ice clouds. The colorful bands, which flow in opposite directions at various latitudes, result from different atmospheric pressures. Lighter bands rise higher and have thicker clouds than the darker bands."[1]


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 A. Simon and M.H. Wong (27 June 2019). "Hubble's New Portrait of Jupiter". Hubble Site. Retrieved 9 August 2019.

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