Portal:Jupiter

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Jupiter

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.

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Selected radiation astronomy

Reds

Main articles: Radiation astronomy/Reds and Red astronomy

File:Jupiter-panel-1879-2014-comp.jpg

At left, Photograph of Jupiter's enormous Great Red Spot in 1879 from "A History of Astronomy in the 19th Century". Credit: Agnes Clerk and NASA.

The Great Red Spot (GRS) is a persistent anticyclonic storm, 22° south of Jupiter's equator, which has lasted for at least 194 years and possibly longer than 359 years. The storm is large enough to be visible through Draft:Earth-based telescopes. Its dimensions are 24–40,000 km west–to–east and 12–14,000 km south–to–north. The spot is large enough to contain two or three planets the size of Earth. At the start of 2004, the Great Red Spot had approximately half the longitudinal extent it had a century ago, when it was 40,000 km in diameter. The Great Red Spot's latitude has been stable for the duration of good observational records, typically varying by about a degree.

It is not known exactly what causes the Great Red Spot's reddish color. Theories supported by laboratory experiments suppose that the color may be caused by complex organic molecules, red phosphorus, or yet another sulfur compound. The Great Red Spot (GRS) varies greatly in hue, from almost brick-red to pale salmon, or even white. The reddest central region is slightly warmer than the surroundings, which is the first evidence that the Spot's color is affected by environmental factors. The spot occasionally disappears from the visible spectrum, becoming evident only through the Red Spot Hollow, which is its niche in the South Equatorial Belt. The visibility of GRS is apparently coupled to the appearance of the SEB; when the belt is bright white, the spot tends to be dark, and when it is dark, the spot is usually light. The periods when the spot is dark or light occur at irregular intervals; as of 1997, during the preceding 50 years, the spot was darkest in the periods 1961–66, 1968–75, 1989–90, and 1992–93.

"Jupiter’s most celebrated atmospheric beauty mark, the Great Red Spot (GRS), has been shrinking for years. When I was a kid in the ’60s peering through my Edmund 6-inch reflector, not only was the Spot decidedly red, but it was extremely easy to see. Back then it really did span three Earths."

"In the 1880s the GRS resembled a huge blimp gliding high above white crystalline clouds of ammonia and spanned 40,000 km (25, 000 miles) across. You couldn’t miss it even in those small brass refractors that were the standard amateur observing gear back in the day. Nearly one hundred years later in 1979, the Spot’s north-south extent has remained virtually unchanged, but it’s girth had shrunk to 25,000 km (15,535 miles) or just shy of two Earth diameters. Recent work done by expert astrophotographer Damian Peach using the WINJUPOS program to precisely measure the GRS in high resolution photos over the past 10 years indicates a continued steady shrinkage:" 2003 Feb – 18,420km (11,445 miles) 2005 Apr – 18,000km (11,184) 2010 Sep – 17,624km (10,951) 2013 Jan – 16,954km (10,534) 2013 Sep – 15,894km (9,876) 2013 Dec – 15,302km (9,508) = 1.2 Earth diameters.

"Not only has the Spot been shrinking, its rotation period has been speeding up. Older references give the period of one rotation at 6 days. John Rogers (British Astronomical Assn.) published a 2012 paper on the evolution of the GRS and discovered that between 2006 to 2012 – the same time as the Spot has been steadily shrinking – its rotation period has spun up to 4 days."

"Rogers also estimated a max wind speed of 300 mph, up from about 250 mph in 2006. Despite its smaller girth, this Jovian hurricane’s winds pack more punch than ever. Even more fascinating, the Great Red Spot may have even disappeared altogether from 1713 to 1830 before reappearing in 1831 as a long, pale “hollow”. According to Rogers, no observations or sketches of that era mention it. Surely something so prominent wouldn’t be missed. This begs the question of what happened in 1831. Was the “hollow” the genesis of a brand new Red Spot unrelated to the one first seen by astronomer Giovanni Cassini in 1665? Or was it the resurgence of Cassini’s Spot?"

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Selected topic

Poles

Main articles: Astronomy/Poles and Poles

File:Mottled toward North Pole.jpg

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.

File:North Pole hemisphere.jpg

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.

File:South Pole hemisphere.jpg

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."

"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."

"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."

"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."

"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."

"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."

"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]."

"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."

References

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Selected astronomy

Jupiter systems

Main articles: Planets/Jupiter/Systems and Jupiter systems

Jupiter rings are photographed by Voyager 2 (false color). Credit: NASA, Voyager 2.

Center is a Voyager 2 image of Jupiter's rings.

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Selected deity

Zeus

Main article: Classical planets/Zeus

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.

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Selected image

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

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Selected meteor

Blue vortex

Main articles: Radiation astronomy/Blues and Blue astronomy

File:Image from NASA’s Juno spacecraft.jpg

Jupiter is shown in an image from NASA’s Juno spacecraft. Credit: Kevin M. Gill, JPL-Caltech/NASA, SWRI, MSSS.{{fairuse}}

This image shows distorted bands of clouds near the blue vortex on Jupiter captured by the Juno spacecraft.

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Selected moon

Io

Main articles: Rocks/Rocky objects/Io and Draft:Io

This is a true-color image of Io taken by the Galileo probe. Credit: NASA.

Io is a rocky-object that is irradiated by the Sun.

Io is also in a planetary-type orbit around Jupiter.

In the image, "[t]he smallest features that can be discerned are 2.5 kilometers in size. There are rugged mountains several kilometers high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. The picture is centered on the side of Io that always faces away from Jupiter; north is to the top."

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Selected theory

Jupiter systems

Main articles: Planets/Jupiter/Systems and 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."

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