Just days before the arrival of NASA’s Juno spacecraft at Jupiter on 4 July, astronomers using the Hubble Space Telescope have observed brilliant auroral displays at Jupiter’s north polar region. It should be noted that this is not the first instance the Hubble telescope has been used to observe aurorae on Jupiter, Saturn, Uranus and Neptune.
Aurorae (pl. Latin) are produced when charged particles from the sun interact with a planet’s upper atmosphere to produce spectacular displays of varying complexity and color.
A planet’s magnetosphere is generated deep inside a planet fortunate enough to have one. In the case of Jupiter, Saturn and the rest of the outer gas giant planets, their cores, having been severely compressed by the crushing pressure of the atmosphere above, behave like a metal. This “metallic” core, combined with a relatively rapid rotation, produces a powerful magnetic dynamo and resulting magnetosphere. The same principle applies for the Earth too with the exception that the Earth’s magnetic dynamo is produced at the interface of the solid-iron inner core and the semi-molten iron outer core. As is the case with all planets so protected, Jupiter’s powerful magnetosphere prevents direct bombardment by the Solar Wind. However, and this is true for us here on Earth too, Aurorae are produced when the charged particles of the Solar Wind follow the magnetic lines of force to the poles and bombard those regions of the planet’s upper atmosphere. This process also produces natural Ozone “holes” in the case of the Earth as Ozone is disassociated by exposure to the Solar Wind. The dazzling displays are produced by the ionization and excitation of atmospheric gases in the upper atmosphere, emitting light of varying colors and complexity.
All our science, measured against reality, is primitive and childlike-and yet it is the most precious thing we have
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