The Physics
Factbook
An encyclopedia of scientific essays

Magnetic Field on Jupiter

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Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
Foster, Robert J. Merrill Earth Science Series. Ohio: Bell & Howell, 1985. "Jupiter has a magnetic field about ten times stronger than that of the earth." 500 µT
"Jupiter." Funk & Wagnell's New Encyclopedia. USA: Funk & Wagnell, 1976. "… 14 times stronger than the Earth's." 700 µT
Murrill, Mary Beth. "The Grandest Tour: Voyager." Mercury. 22, 3 (May/June 1993): 66. "… more than 10 times stronger than that of Earth." 500 µT
Davis, Don and Carolyn Collins Petersen. Planetary Exploration: Jupiter. New York: BLA, 1989. "… 4,000 times greater than the Earth's." 0.2 T
Booth, Nicholas. Exploring the Solar System.Cambridge: Cambridge University, 1996. "… generate a magnetic field some 20,000 times more powerful than the Earth's." 1 T

At approximately 140,000 km (90,000 miles) in diameter and 1.9 × 1027 kg in mass, Jupiter is the largest and the most massive planet in our solar system. With 16 moons orbiting around it, it appears as a miniature solar system with Jupiter as the sun. Jupiter's magnetic field is much stronger than that of the Earth.

Moving charge is the source of all magnetism. The magnetosphere is the region around a planet where the magnetic field controls the behavior of electrically charged particles. Most of Jupiter's interior is composed of hydrogen. This hydrogen changes form gas to liquid under the enormous pressure of the planet. Traveling into the insides of Jupiter, the hydrogen becomes a liquid at 960 meters (600 miles) below the surface and at 16,000 meters (10,000 miles) it is crushed so hard that (according to one source) atoms are destroyed. Here hydrogen behaves like a metal, conducting electricity. The strong magnetic field around Jupiter is created by the flow of electricity through the metallic hydrogen.

Voyager 2 was launched on August 20, 1977 from Cape Canaveral and Voyager 1 was launched that September into Space. Both were equipped with instruments to carry out scientific investigations. In 1979 they passed Jupiter. The results of the Voyager missions revealed that the field was 10 times stronger than that of the Earth. The magnetic field at the surface of the Earth is 4.5 × 10−5 tesla. (Voyager 1 and 2 still continue to explore the galaxy trying to determine the boundaries between solar wind and interstellar space and studying the stars' ultraviolet sources.)

Jupiter's magnetic field ranges from 5 × 10−4 to 1 T. This great difference may be due to the field varying with distance from the surface of the planet. The polarity of a planet changes over time, (Jupiter's polarity is opposite of the Earth's,) and since the study of the Earth's magnetism revealed that the magnetic field varies in different places on its surface, the changing polarity position will change the magnetic field at that position. Thus, the magnetic field of Jupiter may vary over time, (but it is highly unlikely -- impossible even -- that it would change in such a short time as that between the measurements introduced here).

Aleksandra Czajka -- 1999

Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
"New Finding's Support Prospect Life on Jupiter." Earth Changes TV.January 2000. "Jupiter has the strongest magnetic field of any planet, Chyba says, more than 10 times stronger than Earth's. When protons, electrons, and other particles from space get trapped in Jupiter's magnetosphere, they are accelerated to extremely high velocities." 500 µT
"Jupiter." Britannica Encyclopedia. "The magnetic moment is 19,000 times greater than Earth's, leading to a field strength at the equator of 4.3 gauss, compared with 3.0 gauss at the Earth's surface." 430 µT
"Jupiter's Magnetic Field." Scientific America. "The magnetic field of Jupiter is 19,000 times stronger than the Earth's magnetic field." 900 µT
Chaisson, Eric & McMillan, Steve, Astronomy Today. 2nd Ed. New Jersey: Prentice-Hall, (1997). Chapter 11. "From analysis of the radio frequency emissions, it is implied that the magnetic field of Jupiter is nearly 20,000 times stronger than the Earth's field. With an Earth field of about 0.5 gauss, this implies a magnetic field of about 10,000 gauss or 1 tesla. 1 T
"Magnetic Field." New World Book Encyclopedia. "The force of its magnetism extends far into space in a region surrounding the planet called its magnetic field. Jupiter's magnetic field is about 14 times as strong as Earth's, according to measurements made by spacecraft" 700 µT

Jupiter. Who really cares about that place? It's a lonely planet more than 34 million miles away from Earth. No one ever hears about that planet any ways, right? WRONG! Jupiter is one of the most fascinating planets known to man.

At approximately 140,000 km (90,000 miles) in diameter and 1.9 × 1027 kg in mass Jupiter is by far the largest and most massive of the gas giants in our solar system, hence its name "the Greek King of the Gods."This planet almost seems to have its own miniature solar system with its 16 moons orbiting around it. The sheer volume of the planet is incredible. Twice the mass of the rest of the planets combined is still not enough to equal the mass of Jupiter. Its composition consists roughly of 90% hydrogen and about 10% of helium. The majority of the interior of Jupiter is liquid metallic hydrogen; which has the incredible power to turn into liquid.

What is most amazing is the magnetic filed on Jupiter. The strong magnetic field on Jupiter is created by the flow of electricity through the metallic hydrogen in its interior. Jupiter's magnetic field traps electrons, protons, and other electrically charged particles in radiation belts around the planet. The particles are so powerful that they can damage instruments aboard spacecraft operating near the planet. Space explorations from the Voyager 1 that was launched September of 1977 and from Voyager 2 launched on August 20, 1977 experienced just this. In 1979 they passed Jupiter. The results of these missions revealed that the magnetic field was 10 times stronger than that of the Earth. The magnetic field of earth is 4.5 × 10−5 tesla.

From analysis of the radio frequency emission, it is implied that the magnetic field on Jupiter is nearly 20,000 times stronger that that of Earth. With Earth's field of about 0.5 gauss, this implies that Jupiter's field is about 10,000 gauss or 1 tesla. Other results reveal the magnetic moment is 19,000 times greater than Earth's. This leads to a strength of 4.3 gauss at the equator, compared to the 0.3 gauss at the Earth's surface. Jupiter's magnetic field ranges from 5 × 10−4 T to 1 T. There is no definite explanation as to why there is variations in Jupiter's magnetic field, but the best fit explanation is that all research done on Jupiter was made from different distances. Each aircraft studied Jupiter from a different locale, which in turn gives way to varying results. How close scientists came to Jupiter makes a different in their results.

Priscilla Veronica Chen -- 2001