Jupiter Jupiter
Jupiter is the fifth planet from the Sun and is the largest one in the solar system. If Jupiter were hollow it could fit over a thousand Earths within itself. It also contains more matter than all of the other planets combined. It has a mass of 1.9 x 10^27 kg and is 142,800 km (88,240 mi) across the equator. Jupiter possess 16 satellites. Four of which were even observed by Galileo as long ago as 1610. There is a ring system but it is very faint and is totally invisible from the Earth. The atmosphere is very deep, perhaps comprising the whole planet and is somewhat like the Sun. It is composed mainly of hydrogen and helium, with small amounts of methane, ammonia, water vapor and other compounds. At great depths, within Jupiter, the pressure is so great that the hydrogen atoms are broken up and the electrons are freed so that the resulting atoms consist of bare protons. This produces a state in which the hydrogen becomes metallic.
Colorful latitudinal bands and atmospheric clouds and storms illustrate Jupiter's dynamic weather systems. The cloud patterns change constantly within hours and days. The Great Red Spot is a complex storm moving in a counter-clockwise direction. At the outer edge, material appears to rotate in four to six days; near the center, motions are small and nearly random in direction. An array of other smaller storms and eddies can be found through out the banded clouds.
Auroral emissions, similar to Earth's northern lights, were observed in the polar regions of Jupiter. The auroral emissions appear to be related to material from Io that spirals along magnetic field lines to fall into Jupiter's atmosphere. Cloud-top lightning bolts, similar to superbolts in Earth's high atmosphere were also observed.
Unlike Saturn's intricate and complex ring patterns, Jupiter has a single ring that is almost uniform in its structure. It is probably composed of dust particles less than 10 microns in diameter -- about the size of cigarette smoke particles. It extends to an outer edge of about 129,000 km (80,000 miles) from the center of the planet and inward to about 30,000 km (18,000 miles). The origin of the ring is probably from micrometeorite bombardment of the tiny moons orbiting within the ring.
Jupiter's rings and moons exist within an intense radiation belt of electrons and ions trapped in the planet's magnetic field. These particles and fields comprise the jovian magnetosphere or magnetic environment, which extends 3 to 7 million kilometers toward the Sun, and stretches in a windsock shape at least as far as Saturn's orbit - a distance of 750 million kilometers (460 million miles).
Mass (kg) ......................................... 1.900e+27
Mass (Earth = 1) ................................. 3.1794e+02
Equatorial radius (km) ............................... 71,492
Equatorial radius (Earth = 1) .................... 1.1209e+01
Mean density (gm/cm^3) ................................. 1.33
Mean distance from the Sun (km) ................. 778,330,000
Mean distance from the Sun (Earth = 1) ............... 5.2028
Rotational period (hours) ............................. 9.841
Orbital period (years) .............................. 11.8623
Mean orbital velocity (km/sec) ........................ 13.07
Orbital eccentricity ................................. 0.0483
Tilt of axis ........................................... 3.13°
Orbital inclination ................................... 1.308°
Equatorial surface gravity (m/sec^2) .................. 22.88
Equatorial escape velocity (km/sec) ................... 59.56
Visual geometric albedo ................................ 0.52
Magnitude (Vo) ........................................ -2.70
Mean cloud temperature ............................... -121°C
Atmospheric pressure (bars) ............................. 0.7
Atmospheric composition
Hydrogen ............................................ 90%
Helium .............................................. 10%
Animations of Jupiter
Jupiter
(GIF, 265K)
This image was taken by the Wide Field/Planetary Camera of the
Hubble telescope. It is a true color composite of the full disk of
Jupiter. All
features in this image are cloud formations in the Jovian atmosphere,
which contain small crystals of frozen ammonia and traces of colorful
compounds of carbon, sulfur and phosphorous. This photograph was
taken on 28th May, 1991. (Courtesy NASA/JPL).
Nordic Optical Telescope
(GIF, 56K)
This image of Jupiter was taken with the 2.6 m
Nordic Optical
Telescope, located at La Palma, Canary Islands. It is a good
example of the best imagery that can be obtained from earth based
telescopes.
(c) Nordic Optical Telescope Scientific Association (NOTSA).
Jupiter and Moons
(GIF, 114K)
Voyager 1 took this photo of Jupiter and two of its satellites
(Io left and Europa
right) on Feb. 13, 1979. In this view,
Io is about 350,000
kilometers (220,000 miles) above Jupiter's
Great Red Spot, while
Europa is about 600,000 kilometers (375,000 miles) above
Jupiter's clouds. Jupiter is about 20 million kilometers (12.4
million miles) from the spacecraft at the time of this photo.
There is evidence of circular motion in Jupiter's atmosphere. While the
dominant large scale motions are west-to-east, small scale
movement includes eddy like circulation within and between the
bands. (Courtesy NASA/JPL)
The Great Red Spot
(GIF, 144K;
GIF, 413K)
This dramatic view of Jupiter's Great Red Spot and its
surroundings was obtained by Voyager 1 on Feb. 25, 1979, when the
spacecraft was 5.7 million miles (9.2 million kilometers) from
Jupiter. Cloud details as small as 100 miles (160 kilometers)
across can be seen here. The colorful, wavy cloud pattern to the
left of the Red Spot is a region of extraordinarily complex and
variable wave motion. (Courtesy NASA/JPL).
Ring of Jupiter
(GIF, 13K)
The ring of Jupiter was discovered by Voyager 1 in March of 1979.
This image was taken by Voyager 2 and has been pseudo colored. The
Jovian ring is about 6500 km wide and probably less than 10 km thick.
(Credit: Calvin J. Hamilton, Los Alamos National Laboratory)
Moons of Jupiter
(GIF, 261K;
TIF, 2M)
This image shows to scale Jupiter's moons Amalthea, Io, Europa,
Ganymede and Callisto.
(Credit: Calvin J. Hamilton, Los Alamos National Laboratory)
Name Distance* Width Thickness Mass Albedo ---------------------------------------------------------------- Halo 100,000 km 22,800 km 20,000 km ? 0.05 Main 122,800 km 6,400 km < 30 km 1 x 10^13 kg 0.05 Gossamer 129,200 km 850,000 km ? ? 0.05
*The distance is measured from the planet center to the start of the ring.
Sixteen moons have been discovered orbiting around Jupiter. Most of them are relatively small and seem to have been more likely captured than to have been formed in orbit around Jupiter. Four of the largest moons, Io, Europa, Ganymede and Callisto, are believed to have accreted as part of the process by which Jupiter itself formed. The following table summarizes the radius, mass, distance from the planet center, discoverer and the date of discovery of each of the moons of Jupiter:
Radius Mass Distance
Moon # (km) (kg) (km) Discoverer Date
-------------------------------------------------------------------
Metis XVI 20 9.56e+16 127,969 S. Synnott 1979
Adrastea XV 12.5x10x7.5 1.91e+16 128,971 Jewitt-Danielson 1979
Amalthea V 135x84x75 7.17e+18 181,300 E. Barnard 1892
Thebe XIV 55x45 7.77e+17 221,895 S. Synnott 1979
Io I 1,815 8.94e+22 421,600 Marius-Galileo 1610
Europa II 1,569 4.80e+22 670,900 Marius-Galileo 1610
Ganymede III 2,631 1.48e+23 1,070,000 Marius-Galileo 1610
Callisto IV 2,400 1.08e+23 1,883,000 Marius-Galileo 1610
Leda XIII 8 5.68e+15 11,094,000 C. Kowal 1974
Himalia VI 93 9.56e+18 11,480,000 C. Perrine 1904
Lysithea X 18 7.77e+16 11,720,000 S. Nicholson 1938
Elara VII 38 7.77e+17 11,737,000 C. Perrine 1905
Ananke XII 15 3.82e+16 21,200,000 S. Nicholson 1951
Carme XI 20 9.56e+16 22,600,000 S. Nicholson 1938
Pasiphae VIII 25 1.91e+17 23,500,000 P. Melotte 1908
Sinope IX 18 7.77e+16 23,700,000 S. Nicholson 1914
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