The new NASA study confirms that Saturn loses its iconic tire from the maximum amount estimated by Voyager 1 & 2 decade ago. The rings are drawn to Saturn's gravitation as dusty ice crystals under the influence of the Saturn's magnetic field.
"We appreciate that this" ring "will lower the amount of water that could fill the Olympic size pool of Saturn tires in half an hour," said James O & # 39; Donoghue NASA's Goddard Space Flight Center in Greenbelt, Maryland. "This alone alone removes the entire tire system from 300 million years, but adds the tire material measured to this Cassini space meter, which is detected by the Saturn equator and the tire has less than 100 million years of life, short, compared to Saturn's over 4 billion years of age. prepared Saturn's rain study Icarus December 17.
Scientists have long wondered whether Saturn was formed with tires or whether the planet had acquired them later in life. The new study favors the latter scenario, indicating that they are unlikely to be over 100 million years since the C-ring would have been so long that it would now assume that it was as dense as the B-ring. "We are fortunate to be watching the ring system of Saturn, which seems to be in the midst of your life, but if the tires are temporary, maybe we're just losing sight of Jupiter, Uranus and Neptune's giant ring systems, which are just a thin ring today!" Donoghue added.
Various theories have been suggested for the origin of the ring. If the planet took them later in life, the rings could have been formed when small, icy moons on the orbit around Saturn collided, perhaps because their orchestra was disturbed by the gravitational tug of an asteroid or comet to be driven.
The first tips that spilled the rain were from Voyager's perceptions that were apparently unrelated to the phenomena: the randomly electronically charged upper atmosphere (ionosphere), the density variations of the Saturn rings, and the trio of narrow dark bands that surround the planet in the northern latitudes. These dark bands emerged from NASA's Voyager 2 tour of the Saturn's dark space (stratosphere) described in 1981.
In 1986 NASCon Goddard's Jack Connerney published the Geofysical Research Letters, which linked these narrow dark bands to the form of a huge magnetic field in Saturn, and suggested that the electrically charged ice crystals of Saturn's rings flow through the invisible magnetic field lines, the upper atmosphere of Saturn, from which these lines appeared on the planet. The tire flux that appears at certain latitudes will outstrip the stratospheric mist, making it look dark in reflected light, producing narrow dark bands taken on Voyager.
Saturn's rings are mostly particles that vary in size from microscopic dusty boulders to boulders of several meters. The ring pieces are in balance with Saturn's gravitational pull that wants to drag them back to the planet and their orbit that wants to throw them out into space. Small particles can be electrically charged with ultraviolet light from the sun or plasma poles from micrometeoric bombardment of the tires. When this happens, the particles can feel Saturn's magnetic field wagon, which turns inward toward the planet with the rings of Saturn. In some parts of the tires when loaded, the balance of these small particles is dramatically changed and Saturn's gravity forces them into the magnetic field lines into the upper atmosphere.
Afterwards, the icy icy particles vaporize and the water can react chemically with the ionosphere of Saturn. One of these reactions is the growth in the life span of electron-charged particles, i.e. H3 +, consisting of three protons and two electrons. As the sunlight intensifies, the H3 + ions glow in the infrared light that the O-Donoghue team observed with Keck telescopic attachment means in Mauna Kea, Hawaii.
Their observations revealed the glowing bands in the northern and southern hemisphere of Saturn, where the magnetic field lines intersect the ring tile to reach the planet. They analyzed the light to determine the amount of rain in the ring and its effects on the ionosphere of Saturn. They found that the amount of rain well fits well with Connerney and colleagues over the past three decades to get an astonishingly high value, and one of the southern regions most benefits from it.
The team also found a glowing tape at a higher latitude in the southern hemisphere. At this point, Saturn's magnetic field cuts Encelador's geologically active moon's orbit, which fires water ghews into space, indicating that part of the particles also sat on Saturn. "It was not a complete surprise," said Connerney. "We identified Enceladus and E ring as an abundant source of water based on another dark black band in the old Voyager image." The geysers first detected by Cassini instruments in 2005 are believed to come from the ocean of liquid water under the frozen surface of a small moon. Its geological activity and the ocean's ocean make Enceladus one of the most promising places to look outside the planet.
The team would like to see how rain cover changes during Saturn's seasons. As the planet progresses in a 29.4 year orbit, the rings are exposed to the Sun at varying degrees. Because the ultraviolet-white sunlight decreases the grains of ice and makes them responsible for Saturn's magnetic fields, varying exposure to sunlight changes the amount of tire.
The research was funded by NASA and NASA's postgraduate program at NASA Goddard, administered by the University Space Research Association. W. M. The Keck Observatory is a scientific partner between the California Technical University, the University of California and NASA and its files are available from the Keck Archives. The authors want to acknowledge the significant cultural role and respect that the Mauna Kea Summit has in the indigenous Hawaiian community; they are lucky to be able to make observations of this mountain.
Bill Steigerwald / Nancy Jones
NASA Goddard Space Landing Center, Greenbelt, Maryland
301-286-8955 / 301-286-0039
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