Aurorae on Uranus. Credit: ESA/Hubble & NASA, L. Lamy / Observatoire de Paris.
Apr 12, 2017
Bright aurorae are found throughout the Solar System.
Just as the system of the sun, planets and comets is put in motion by the forces of gravity, and its parts persist in their motions, so the smaller systems of bodies also seem to be set in motion by other forces and their particles to be variously moved in relation to each other and, especially, by the electric force.
—Isaac Newton
Since Uranus takes 84.3 Earth years to revolve around the Sun, telescopes have not had much time to investigate its surface and surroundings. The Keck telescope in Hawaii came on line in November 1990 and its first use of adaptive optics did not take place until October 2003, so detailed images from Earth were not available due to atmospheric distortion.
Uranus is 50,724 kilometers in diameter at the equator, although its equator is tilted almost 90 degrees past horizontal when compared to other planets in the Solar System. Most of them are tilted no more than 24 degrees past vertical, meaning that Uranus rotates on its side. The Hubble Space Telescope began observations of Uranus around 1998, eventually revealing aurorae on Uranus—a surprise to planetary scientists. Since the magnetic field on Uranus is inclined by 59 degrees from its spin axis, aurorae are not near the planet’s poles.
Jupiter and Saturn are known to erupt with bright aurorae, but those on Uranus are not well studied because of its distance. Hubble was the first to gather an image of the aurorae on Uranus in 2012 and used a spectrograph to analyze their ultraviolet characteristics in 2014. To everyone in the consensus astronomical community’s surprise, the solar wind instigated intense aurorae at the gas giant’s electromagnetic poles. A recent press release confirms those observations.
Uranus is subject to gigantic electrical storms that seem to appear from nowhere. Planetary scientists do not know why they occur, but they look similar to storms that are seen on Jupiter and Saturn. Like its sister gas giants, Uranus radiates more energy than it receives from the Sun: 1.1 times more radiation than it receives.
Saturn’s “mysterious” dragon storm periodically makes its way around the entire planet. Jupiter’s Great Red Spot is hotter than its surroundings and has been spinning for more than 300 years. In each case, the power needed to drive those phenomena comes from electricity. Since Uranus averages – 214 Celsius, it is difficult to account for its 585 kilometer per hour wind speeds. The anomalous winds, the aurorae, and the faint ring system are probably caused by electrical processes found throughout the cosmos.
Uranus, like Saturn and Jupiter, possesses a Langmuir charge sheath (plasmasphere) that isolates it from the Sun’s own charge sheath. The Sun, in turn, is isolated from the charged interstellar medium. The Sun’s interaction with the flow of electric charge in the Solar System can explain the effects discovered by astronomers on Uranus. Like its sisters, the environment around Uranus is highly charged. Could objects traveling through its vicinity, like its larger moons, initiate substantial electrical events in the same way that sungrazer comets do?
Uranus is a highly charged object in a state of dynamic equilibrium, so one or more of its moons are most likely connected to it in the same way that Io is connected to Jupiter with powerful “flux ropes”. Those connections get stronger when the solar wind adds charge density to each body. More prolonged observations should confirm an Electric Universe model of the Solar System.
Stephen Smith
