The image at top right shows Jovian aurora observed on February 8, 1992, by the European Space Agency's Faint Object Camera (FOC) aboard NASA's Hubble Space Telescope (HST). This is the first direct image of the aurora taken in ultraviolet light (1600 Angstroms) and the best auroral images ever. An earlier image of Jupiter's full disk (lower left), obtained by HST's Wide Field/Planetary Camera, shows the location of the northern aurora (box) with respect to the rest of the planet.
The FOC image shows the aurora is not uniformly bright, but rather there is a region of significantly increased brightness toward the west (right) side. This effect has not yet been explained fully.
The bright oval shape of the aurora corresponds approximately to the position where magnetic field lines passing through the orbit of the Jovian satellite, Io, enter Jupiter's atmosphere. This is strong circumstantial evidence that Io is the source of the particles that cause the aurora. In 1980, Voyager discovered that Io has an extraordinarily active volcano system, and many observations have determined that volcanic particles escape from Io into the Jovian magnetosphere.
HST observations were made simultaneously with the Jupiter flyby of the NASA/ESA Ulysses spacecraft. (Ulysses flew by Jupiter to be gravitationally boosted onto a trajectory that will carry it over the Sun's southern pole. While at Jupiter, Ulysses took advantage of the opportunity to make measurements of the Jovian magnetosphere. Ulysses does not have an onboard camera.)
The aurora provides useful information about Jupiter's magnetic field and how high energy particles from the magnetosphere influence the temperature, chemical composition and winds at the planet's northern pole.
Credits
John Caldwell, Institute for Space and Terrestrial Science, and York University; and NASA/ESA| About The Object | |
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| Object Name | Jupiter |
| About The Object | |
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| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
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| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
