Cloud bands are clearly visible on Jupiter. Credit: NASA/JPL/USGS.

Jupiter is the largest planet in the Solar System and contains nearly 3/4 of all planetary matter.

With no solid surface, Jupiter is a gas and liquid filled giant. Its turbulent belts of clouds circulate parallel to the equator and often contain oval spots which are storm systems with the largest being easily twice the diameter of Earth. The great red spot has been observed for at least 300 years and rotates counter-clockwise with wind speeds of 270 miles per hour [430 km/hr].

Although observed and studied from Earth for centuries it wasn't until the mid 1970's that humans were able to get a closer look with the spacecraft Pioneer 10 and 11. The Voyager 1 and 2 spacecraft were launched with the specific purpose of collecting information and data on the Jovian worlds. In December 1995 the Galileo spacecraft entered into orbit and began it's long-term study of Jupiter and it's moons, a probe was also sent deep into the atmosphere of the gas giant.

Selected radiation astronomy


Full-disc view of Jupiter is in natural color in April 2014. Credit: Hubble Space Telescope.

There is anecdotal evidence that people had seen the Galilean moons of Jupiter before telescopes were invented.[1]


  1. Zezong, Xi, "The Discovery of Jupiter's Satellite Made by Gan De 2000 years Before Galileo", Chinese Physics 2 (3) (1982): 664–67.
Selected topic


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.
Selected astronomy

Aurora astronomy

This image of Jupiter shows concentrations of auroral X-rays near the north and south magnetic poles. The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Credit: NASA/CXC/SWRI/G.R.Gladstone et al.
Aurora at Jupiter's north pole is seen in ultraviolet light by the Hubble Space Telescope. Credit: John T. Clarke (U. Michigan), ESA, NASA.

The "image of Jupiter shows concentrations of auroral X-rays near the north and south magnetic poles."[1] The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Note that X-rays from the entire globe of Jupiter are detected.

Second is an ultraviolet image of aurora at Jupiter's north pole by the Hubble Space Telescope.


  1. NASA/CXC/SWRI/G.R.Gladstone; et al. (February 27, 2002). Jupiter Hot Spot Makes Trouble For Theory. Cambridge, Massachusetts: Harvard-Smithsonian Center for Astrophysics. Retrieved 2012-07-11.
Selected deity


Zeus and his eagle are the statue. Credit: Marcus Cyron.{{free media}}

In the ancient Greek religion, Zeus (Ancient Greek is the "Father of Gods and men". He is the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and Etruscan counterpart is Tinia. Zeus is the child of Cronus and Rhea, and the youngest of his siblings. In most traditions he is married to Hera, although, at the oracle of Dodona, his consort is Dione: according to the Iliad, he is the father of Aphrodite by Dione.

Selected image
Jupiter X-ray Aurora Chandra.jpg

This image of Jupiter shows concentrations of auroral X-rays near the north and south magnetic poles. The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Credit: NASA/CXC/SWRI/G.R.Gladstone et al.

The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Note that X-rays from the entire globe of Jupiter are detected.

Selected meteor


Jupiter seems to be in a transition state between a luminous sun and an opaque world. Credit: Unknown.{{free media}}
Appearance of the sunspots on July 25 is between 1883 and 1884. Credit: Unknown.{{free media}}

"EVERYBODY who watched the sun with a telescope last summer must have wondered at the great belt of spots lying across the southern part of the disk during the last half of July. Several of the spots and groups were of extraordinary size, and their arrangement was very singular. When the belt extended completely across the sun, there was visible at one time almost every characteristic form that sun-spots present. There was the yawning black chasm with sharply defined yet ragged edges, vast enough to swallow up the whole earth, with room to spare, and surrounded by a regular penumbral border as evenly shaded as an artist could have made it; there was the double or triple spot whose black centers, though widely separated from one another, were tangled, as it were, in one twisted and torn veil of penumbra, or connected by long, shadowy bands; there was the monstrous spot of grotesque form surrounded by a crowd of smaller spots of even more fantastic shape, and enveloped in a broad, irregular penumbra as bizarre and wonderful as the mighty sun-chasms inclosed in it; there was the great spot, often of singular outline, accompanied outside its shadowy borders by one or more swarms of minute black specks pitting the white photosphere in the most extraordinary fashion; there was the huge group, visible even to the unassisted eye, and consisting of half a dozen or more large spots intermingled with smaller ones whose number seemed to defy counting, and enveloped in a penumbral cloak of becoming amplitude; there, near the edges of the disk, were the crinkling lines and heaped-up masses of faculæ, the mountainous hydrogen-flames which marked the places where the intensest solar action was going on—in short, there was a panorama in which every variety of sun-spot seemed to be passing in a gigantic procession across the disk. And what a procession it was!—long enough, nearly, to reach from the earth to the moon and back again three times!"[1]

The appearance of Jupiter during sun flare activity is shown.


  1. GARRETT P. SERVISS (December 1883). "A BELT OF SUN-SPOTS". Popular Science Monthly 24 (12): 180-6. https://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_24/December_1883/A_Belt_of_Sun-Spots. Retrieved 28 June 2018. 
Selected moon


A true color image of Ganymede is acquired by the Galileo spacecraft on June 26, 1996. Credit: NASA/JPL.
This is global pictoral map of Ganymede. Credit: National Oceanic and Atmospheric Administration/USGS.

"If Ganymede rotated around the Sun rather than around Jupiter, it would be classified as a planet."[1]

The Galilean Moons is a "name given to Jupiter's four largest moons, Io, Europa, Callisto & Ganymede. They were discovered independently by Galileo Galilei and Simon Marius."[2]

"Ganymede has a very distinct surface with bright and dark regions. The surface includes mountains, valleys, craters and lava flows. The darker regions are more heavily littered with craters implying that those regions are older. The largest dark region is named Galileo Regio and is almost 2000 miles [3200 km] in diameter. The lighter regions display extensive series of troughs and ridges, thought to be a result of tectonic movement."[1]

"A notable attribute of the craters on Ganymede is that they are not very deep and don’t have mountains around the edges of them as can normally be seen around craters on other moons and planets. The reason for this is that the crust of Ganymede is relatively soft and over a geological time frame has flattened out the extreme elevation changes."[1]


  1. 1.0 1.1 1.2 Bjorn Jonsson and Steve Albers (October 17, 2000). Ganymede (Jupiter moon). NOAA. Retrieved 2012-07-01.
  2. Aravind V R (April 17, 2012). Astronomy glossary. Retrieved 2013-06-22.
Selected theory

Jupiter systems

"A definite color gradient is observed [in the small inner satellites of Jupiter], with the satellites closer to Jupiter being redder: the mean violet/green ratio (0.42/0.56 μm) decreases from Thebe to Metis. This ratio also is lower for the trailing sides of Thebe and Amalthea than for their leading sides."[1]


  1. P.C. Thomas, J.A. Burns, L. Rossier, D. Simonelli, J. Veverka, C.R. Chapman, K. Klaasen, T.V. Johnson, M.J.S. Belton, Galileo Solid State Imaging Team (September 1998). "The Small Inner Satellites of Jupiter". Icarus 135 (1): 360-71. doi:10.1006/icar.1998.5976. http://www.sciencedirect.com/science/article/pii/S0019103598959760. Retrieved 2012-06-01.