NationMaster - Encyclopedia: Great Red Spot

The Great Red Spot is a persistent anticyclonic storm on the planet Jupiter, 22° south of the equator, which has lasted for at least 178 years and possibly as long as 343 years or more. The storm is large enough to be visible through Earth-based telescopes. It was probably first observed by Giovanni Domenico Cassini, who described it around 1665. The spot has been noticeably red at times throughout its observed history, yet has not been appreciably red in the visible spectrum since a rather brief period in the mid 1970s. Download high resolution version (916x776, 887 KB) Detail of Jupiters atmosphere, as imaged by Voyager 1. ... Download high resolution version (916x776, 887 KB) Detail of Jupiters atmosphere, as imaged by Voyager 1. ... For the album by The Verve, see Voyager 1 (album). ... This article is about Earth as a planet. ... For other uses, see NASA (disambiguation). ... An anticyclonic storm is a weather storm where winds around the storm flow contrary to the direction dictated by the Coriolis effect about a region of low pressure. ... For other uses, see Storm (disambiguation). ... This article is about the astronomical term. ... For other uses, see Jupiter (disambiguation). ... This article is about Earth as a planet. ... This article does not cite any references or sources. ... Giovanni Domenico (Jean-Dominique) Cassini Portrait Giovanni Domenico Cassini (June 8, 1625â€“September 14, 1712) was an Italian astronomer, engineer, and astrologer. ...

Storms such as this are not uncommon within the turbulent atmospheres of gas giants. Jupiter also has white ovals and brown ovals, which are lesser unnamed storms. White ovals tend to consist of relatively cool clouds within the upper atmosphere. Brown ovals are warmer and located within the "normal cloud layer". Such storms can last hours or centuries. In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic, stochastic property changes. ... Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. ... This article does not cite any references or sources. ...

Before the Voyager missions, astronomers were highly uncertain of the Red Spot's nature. Many believed it to be a solid or liquid feature on Jupiter's surface.

Observation history

The Great Red Spot appears at first to be remarkably stable, and most sources concur that it has been continuously observed for 300 years. However, the situation is more complex than that; the present spot was first seen only after 1830 and well-studied only after a prominent apparition in 1879. A long gap separates its period of current study after 1830 from its seventeenth-century discovery; whether the original spot dissipated and re-formed, whether it faded, or even if the observational record was simply poor are all unknown.^[1] Image File history File links Pioneer_10_jup. ... Image File history File links Pioneer_10_jup. ...

For example its first sighting is often credited to Robert Hooke, who described a spot on the planet in May 1664; however, it is likely that Hooke's spot was in the wrong belt altogether (the North Equatorial Belt, versus the current Great Red Spot's location in the South Equatorial Belt). Much more convincing is Giovanni Cassini's description of a "permanent spot" the following year.^[2] With fluctuations in visibility, Cassini's spot was observed from 1665 to 1713; however, the 118-year observational gap makes the identity of the two spots inconclusive, and the older spot's shorter observational history and slower motion than the modern spot make their identity unlikely.^[3] Robert Hooke, FRS (July 18, 1635 â€“ March 3, 1703) was an English polymath who played an important role in the scientific revolution, through both experimental and theoretical work. ... Giovanni Domenico (Jean-Dominique) Cassini Giovanni Domenico Cassini (June 8, 1625 - September 14, 1712) was an Italian-French astronomer and engineer. ...

A minor mystery concerns a Jovian spot depicted in a 1711 canvas by Donato Creti, which is exhibited in the Vatican.^[4]^[5] Part of a series of panels in which different (magnified) heavenly bodies serve as backdrops for various Italian scenes, and all overseen by the astronomer Eustachio Manfredi for accuracy, Creti's painting is the first known to depict the GRS as red. Worth noting is the fact that no Jovian feature was officially described as red before the late 1800s.^[5] Donato Creti (1671 - 1749) was an Italian painter of the Rococo period, active mostly in Bologna. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ...

On February 25, 1979,^[6] when the Voyager 1 spacecraft was 9.2 million km (5.7 million miles) from Jupiter it transmitted the first detailed image of the Great Red Spot back to Earth. Cloud details as small as 160 km (100 miles) across were visible. The colorful, wavy cloud pattern seen to the left (west) of the Red Spot is a region of extraordinarily complex and variable wave motion. Image File history File links Download high-resolution version (895x848, 52 KB) The Great Red Spot as seen from Voyager 1 File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Voyager 1 ... Image File history File links Download high-resolution version (895x848, 52 KB) The Great Red Spot as seen from Voyager 1 File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Voyager 1 ... is the 56th day of the year in the Gregorian calendar. ... Also: 1979 by Smashing Pumpkins. ... For the album by The Verve, see Voyager 1 (album). ...

At the start of 2004, the Great Red Spot had approximately half the longitudinal extent it had a century ago, when it reached a size of 40,000 km. At the present rate of reduction it would become circular by 2040, although this is unlikely because of the distortion effect of the neighboring jet streams. It is not known how long the spot will last, or whether the change is a result of normal fluctuations.^[7] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Categories: Jupiter | Saturn | NASA probes | Astronomy stubs ...

A smaller spot, designated Oval BA, formed recently from the merger of three white ovals, has turned reddish in color. Astronomers have christened it the Little Red Spot or Red, Jr. As of June 5, 2006, the Great Red Spot and Oval BA appeared to be approaching convergence.^[8] The storms pass each other about every two years, but the passings of 2002 and 2004 did not produce anything exciting. But Dr. Amy Simon-Miller, of the Goddard Space Flight Center, predicted the storms would have their closest passing on July 4, 2006. Simon-Miller had been working with Dr. Imke de Pater and Dr. Phil Marcus of UC Berkeley, and a team of professional astronomers since April, studying the storms using the Hubble Space Telescope. On July 20, the two storms were photographed passing each other by the Gemini Observatory without converging.^[9] Oval BA (left) Oval BA (commonly known as Red Spot Jr. ... is the 156th day of the year (157th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... Oval BA (left) Oval BA (commonly known as Red Spot Jr. ... Aerial view of Goddard Space Flight Center. ... is the 185th day of the year (186th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... Sather Tower (the Campanile) looking out over the San Francisco Bay and Mount Tamalpais. ... The Hubble Space Telescope (HST; also known colloquially as the Hubble or just Hubble) is a space telescope that was carried into Earth orbit by the Space Shuttle in April 1990. ... The Gemini Observatory is an astronomical observatory consisting of two 8-metre telescopes at different sites. ...

The Great Red Spot should not be confused with the Great Dark Spot, a feature observed near the northern pole of Jupiter in 2000 with the Cassini–Huygens spacecraft.^[10] Note that a feature in the atmosphere of Neptune was also called the Great Dark Spot. The latter feature was imaged by Voyager 2 in 1989, and may have been an atmospheric hole rather than a storm and it was no longer present as of 1994 (although a similar spot had appeared farther to the north). Cassiniâ€“Huygens is a joint NASA/ESA/ASI unmanned space mission intended to study Saturn and its moons. ... For other uses, see Neptune (disambiguation). ... The Great Dark Spot as seen from Voyager 2 The Great Dark Spot was a dark spot on Neptune similar in appearance to Jupiters Great Red Spot. ... Trajectory Voyager 2 is an unmanned interplanetary spacecraft, launched on August 20, 1977. ...

Structure

The oval object rotates counterclockwise, with a period of about six Earth days^[11] or 14 Jovian days. The Great Red Spot's dimensions are 24–40,000 km west to east and 12–14,000 km south to north. It is large enough to contain two or three planets the size of Earth. The cloudtops of this storm are about 8 km above the surrounding cloudtops. Image File history File linksMetadata Download high resolution version (1865x1599, 358 KB)Rough visual comparison of Jupiter, Earth, and the Great Red Spot. ... Image File history File linksMetadata Download high resolution version (1865x1599, 358 KB)Rough visual comparison of Jupiter, Earth, and the Great Red Spot. ... For other uses, see Cloud (disambiguation). ...

Infrared data has long indicated that the Great Red Spot is colder (and thus, higher in altitude) than most of the other clouds on the planet.^[12] Furthermore, careful tracking of atmospheric features revealed the spot's counterclockwise circulation as far back as 1966, observations dramatically confirmed by the first time-lapse movies from the Voyager flybys.^[13] The spot is confined by a modest eastward jet stream to its south and a very strong westward one to its north.^[14] Though winds around the edge of the spot peak at ~120 m/s (430 km/h), currents inside it seem stagnant, with little inflow or outflow.^[15] The rotation period of the spot has decreased with time, perhaps as a direct result of its steady reduction in size.^[16] For other uses, see Infrared (disambiguation). ... For other uses, see jet stream (disambiguation). ...

The Great Red Spot's latitude has been stable for the duration of good observational records, typically varying by about a degree. Its longitude, however, is subject to constant variation.^[17]^[18] Because Jupiter does not rotate uniformly, astronomers had defined three different systems for defining the latitude. System II is used for longitudes of more than 10°, and was originally based on the average rotation rate of the Great Red Spot of 9h 55m 42s.^[19]^[20] Despite this, however, the spot has "lapped" the planet in System II at least 10 times since the early nineteenth century. Its drift rate has changed dramatically over the years and has been linked to the brightness of the South Equatorial Belt, and the presence or absence of a South Tropical Disturbance.^[21] Image File history File links Download high resolution version (1799x600, 7691 KB) Original Caption Released with Image: The first color movie of Jupiter from NASAs Cassini spacecraft shows what it would look like to peel the entire globe of Jupiter, stretch it out on a wall into the form... Image File history File links Download high resolution version (1799x600, 7691 KB) Original Caption Released with Image: The first color movie of Jupiter from NASAs Cassini spacecraft shows what it would look like to peel the entire globe of Jupiter, stretch it out on a wall into the form... This article is about the geographical term. ... Longitude is the east-west geographic coordinate measurement most commonly utilized in cartography and global navigation. ...

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 sulphur compound, but a consensus has yet to be reached.

The Great Red Spot varies greatly in hue, from almost brick-red to pale salmon, or even white. In fact, the spot occasionally "disappears", becoming evident only through the Red Spot Hollow, which is its niche in the South Equatorial Belt (SEB). Interestingly, its visibility is apparently coupled to the SEB; when the belt is bright white, the spot tends to be dark, and when it is dark, the spot is usually light. These 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.^[1] The cloud pattern on Jupiter is the visible system of coloured cloud tops in the atmosphere of the planet Jupiter, remarkable for its stability. ...

Mechanics

As the hot gases that comprise Jupiter's atmosphere rise from lower levels to higher levels, eddies form and converge. As cooler gas falls back, the Coriolis force causes swirling motion across a region that may be many kilometers in diameter. These eddies can last for a long time, because there is no solid surface to provide friction and because colder cloud tops above the eddy allow little energy to escape by radiation. Once formed, such eddies are free to move, merging with or affecting the behavior of other storm systems in the atmosphere. It is theorized that this mechanism formed the Great Red Spot. According to this theory, many adjacent eddies are engulfed and merge with the spot, adding to the energy of the storm and contributing to its longevity. Image File history File links Jupiter_Great_Red_Spot_Animation. ... Image File history File links Jupiter_Great_Red_Spot_Animation. ... Atmospheres redirects here. ... In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle. ... In physics, the Coriolis effect is an inertial force first described by Gaspard-Gustave Coriolis, a French scientist, in 1835. ... For other uses, see Friction (disambiguation). ... For other uses, see Radiation (disambiguation). ...

See also

The cloud pattern on Jupiter is the visible system of coloured cloud tops in the atmosphere of the planet Jupiter, remarkable for its stability. ... Extraterrestrial cyclones are cyclones found on other planets, typically Jovian planets. ...

Notes and references

Footnotes

^ ^a ^b Beebe (1997), 38-41.
^ Rogers (1995), 6.
^ Rogers (1995), 188.
^ Staff (2003). Astronomical Observations: Donato Creti. Vatican Museums. Retrieved on 2007-06-15.
^ ^a ^b Hockey (1999), 40-1.
^ Smith et al (1979), 951-972.
^ Beatty, J. Kelly (2002). "Jupiter's Shrinking Red Spot". Sky and Telescope 103 (4): 24. Retrieved on 2007-06-21.
^ Phillips, Tony (June 5, 2006). Huge Storms Converge. Science@NASA. Retrieved on 2007-01-08.
^ Michaud, Peter. "Gemini Captures Close Encounter of Jupiter's Red Spots", Gemini Observatory, July 20, 2006. Retrieved on 2007-06-15.
^ Phillips, Tony. "The Great Dark Spot", Science at NASA, March 12, 2003. Retrieved on 2007-06-20.
^ Smith et al (1979), 954.
^ Rogers (1995), 191.
^ Rogers (1995), 194-6.
^ Beebe (1997), 35.
^ Rogers (1995), 195.
^ Rogers, John (July 30, 2006). Interim reports on STB (Oval BA passing GRS), STropB, GRS (internal rotation measured), EZ(S. Eq. Disturbance; dramatic darkening; NEB interactions), & NNTB. British Astronomical Association. Retrieved on 2007-06-15.
^ Reese, Elmer J.; Solberg, H. Gordon (1966). "Recent measures of the latitude and longitude of Jupiter's red spot". Icarus 5 (1-6): 266-273. doi:10.1016/0019-1035(66)90036-4. Retrieved on 2007-06-20.
^ Rogers (1995), 192-3.
^ Stone, Peter H. (1974). "On Jupiter's Rate of Rotation". Journal of Atmospheric Sciences 31: 1471-1472. Retrieved on 2007-06-20.
^ Rogers (1995), 48, 193.
^ Rogers (1995), 193.

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General references

Bertrand Meigh Peek M.A. F.R.A.S. (1891â€“1965) was a British astronomer. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 165th day of the year (166th in leap years) in the Gregorian calendar. ...

External links

Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 165th day of the year (166th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 165th day of the year (166th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 165th day of the year (166th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 166th day of the year (167th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 202nd day of the year (203rd in leap years) in the Gregorian calendar. ... For other uses, see Jupiter (disambiguation). ... Jupiters 4 Galilean moons, in a composite image comparing their sizes and the size of Jupiter (Great Red Spot visible). ... Jupiters outer moons and their highly inclined orbits. ... Atmosphere Surface pressure: trace Composition: 90% sulfur dioxide Io (eye-oe, IPA: , Greek á¿™ÏŽ) is the innermost of the four Galilean moons of Jupiter and, with a diameter of 3,642 kilometers, is the fourth largest moon in the Solar System. ... Apparent magnitude: 5. ... This article is about the natural satellite of Jupiter. ... There is also an asteroid named 204 Kallisto. ... Download high resolution version (840x840, 41 KB) Original Caption Released with Image: This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979. ... The cloud pattern on Jupiter is the visible system of coloured cloud tops in the atmosphere of the planet Jupiter, remarkable for its stability. ... Jupiter has a very large and powerful magnetosphere. ... Oval BA (left) Oval BA (commonly known as Red Spot Jr. ... A schema of Jupiters ring system showing the four main components The rings of Jupiter are a system of planetary rings around the planet Jupiter. ... Jupiters outer moons and their highly inclined orbits. ... The exploration of Jupiter has consisted of a few automated spacecraft visiting the planet since 1973. ... The US Pioneer program of unmanned space missions was designed for planetary exploration. ... Voyager Project redirects here. ... Galileo is prepared for mating with the IUS booster Galileo and Inertial Upper Stage being deployed after being launched by the Space Shuttle Atlantis on the STS-34 mission Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. ... Juno at Jupiter Juno is a NASA mission to Jupiter planned to cost roughly $700 million and scheduled to launch by June 30, 2010. ... It has been suggested that this article or section be merged with Europa (moon). ... A Jupiter-crosser asteroid is an asteroid whose orbit crosses that of Jupiter. ... The Earthly Branches (Chinese: ; pinyin: dÃ¬zhÄ«; or Chinese: ; pinyin: shÃÃ¨rzhÄ«; literally twelve branches) provide one Chinese system for reckoning time. ... Artists conception of a space habitat called the Stanford torus, by Don Davis Space colonization, also called space settlement and space humanization, is the hypothetical permanent autonomous (self-sufficient) human habitation of locations outside Earth. ... Jupiter mass is the unit of mass equal to one Jupiter (1. ... Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. ...

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