This diagram shows the magnetosphere of Jupiter.
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Windows to the Universe original artwork
A magnetometer is an instrument for measuring magnetic fields. Many spacecraft carry magnetometers to measure the magnetic fields around planets. When a spacecraft makes those measurements, what do the measurements tell us?
The planet might have a global magnetic field surrounding it. Earth does, which is why compasses work. So do Mercury, Jupiter, Saturn, Uranus, and Neptune. Electrical currents in Earth's core generate its magnetic field. The core consists of iron and nickel, which are good conductors of electricity. Similarly, Mercury has an iron core which produces its field. Areas surrounding the cores of Jupiter and Saturn are filled with liquid metal hydrogen. This strange substance exists only at the high pressure....To Read More Click Here
Posted by Jay Roberts at 02:19 AM | Permalink
Reviews of Geophysics, 34, 1-31, 1996
David P. Stern, Laboratory for Extraterrestrial Physics
Goddard Space Flight Center, Greenbelt, MD 20771
After 1958, when scientific satellites began exploring the Earth magnetic environment, many puzzling phenomena could be directly examined, especially the polar aurora and disturbances of the Earth's magnetic field [see Stern, 1989a]. The notion of the solar wind, introduced that same year, helped clarify the role of the Sun in driving such phenomena. The large-scale structure of the magnetosphere, the space region dominated by the Earth's magnetic field, was gradually revealed within the next decade: its trapped particles, its boundary, and its long magnetic tail on the night side. Inevitably, however, the new discoveries led to new questions... To Read More .. Click Here..
Posted by Jay Roberts at 02:11 AM | Permalink
Until the middle of the 20th century the Earth's magnetism seemed to be a happy accident of nature. Too many factors had to fit just right--the fluid core of the Earth, its electrical condctivity and its motions, all had to satisfy the strict requirements of dynamo theory.
That was before other planets in the solar system were visited and examined. Now we know that among those planets, only Venus lacks any magnetism. The planets differ greatly in size and properties, and their fields differ too. Yet they all seem to have dynamo fields, or (in the case of Mars and the Moon) have had them in the past.
In early 1955, two young radio-astronomers started working with a cross-shaped antenna array of the Carnegie Institution's Department of Terrestrial Magnetism (DTM). The array could select signals from a narrow range of directions, and Ken Franklin and Bernie Burke calibrated it using a known source, the....Click Here to Read On...
Posted by Jay Roberts at 02:08 AM | Permalink
No. Venus (even though it has liquid in its core) does not have a magnetic field because of its slow rotation, making the liquid not electrically conducting.
Mars does not have a magnetic field, although measurements by space probes have found magnetically active spots because of the iron found in the surface rocks.
Posted by Jay Roberts at 02:05 AM | Permalink