Thursday , November 26 2020

Study: Saturn loses its ring at a rate of "worst case scenario", –

New NASA study confirms that lose their visual Saturn ring at maximum speed estimated by Voyager 1 and 2 observations decades ago. Saturn rings involved in the action of gravity in the form of rain dusty ice particles under a magnetic field of Saturn.

"We believe that this" ring of rain "depletes the amount of water products that could fill an Olympic-size swimming pool with Saturn's rings in half an hour," said James O & # 39; Donoghue from the Goddard Space Flight Center of NASA in Greenbelt, Maryland. "From this alone, the entire ring system will no longer be 300 million years old, but add to that the Cassini spacecraft, measured by the ring material found in the fall of the equator of Saturn and the rings have at least 100 million years to live. This is a relatively short compared to the age of Saturn's more than 4 billion years. »O & # 39; Donoghue with & # 39 is the lead author of a study on the ring of Saturn with rain & # 39 is in Icarus 17 December.

Scientists have long wondered when Saturn was formed with the rings or if the planet has got them later in life. A new study in favor the latter scenario, indicating that they are unlikely to be over 100 million years, as it would take that long for the C-ring to become what she is suggesting today that once was as dense as B-ring. "We are fortunate that around to see the Saturn ring system, which is in the middle of his life. However, if the ring is temporary, perhaps we just missed seeing the giant Jovian ring system, Uranus and Neptune, which have only a thin hair today! "Added by O & # 39; Donoghue.

Various theories have been proposed for the appearance of the ring. If the planet got them later in life, the ring could be formed when the small, icy moons in orbit around Saturn encounter, perhaps because their orbits were outraged by the gravitational tug of neighboring asteroid or comet.

The first hints that ring rain there came from observations of Voyager, seemingly unrelated to the & # 39; make known: a kind of variation in the electric-charged top of Saturn's atmosphere (ionosphere), the density variation in Saturn's rings, and a trio of narrow dark bands encircling the planet northern midlatitudes & # 39; I. These dark stripes with & # 39 appeared in foggy images upper atmosphere of Saturn (stratosphere) made Voyager 2 NASA Mission in 1981 year.

In 1986, Jack Connerney NASA Goddard published a paper in the Journal of Geophysical Research Letters, which relate these narrow dark streaks in the form of a huge magnetic field Saturn offering electrically charged particles of ice from the rings of Saturn flowed invisible magnetic field lines, the discharge of water into the upper atmosphere of Saturn where these lines came from the planet. Inflow of the rings, which occurs in certain latitudes, stratospheric washed away the haze, making it dark in the reflected light, creating a narrow dark stripes captured in Voyager pictures.

Saturn rings basically ice pieces ranging in size from microscopic dust particles to boulders several yards (meters) in diameter. Ring particles get into the balance between the force of Saturn's gravity, which wants to bring them back to the planet and its orbital velocity, which wants to throw them out into space. The smallest particles may be electrically charged to receive ultraviolet light from the sun or by plasma cloud emanating from micro-meteorites bombardment rings. When this occurs, the particles may feel attraction Saturn's magnetic field, which is bent inwardly towards the planet Saturn rings. In some parts of rings, when charged, the balance of power on these small particles is changing dramatically, and Saturn's gravity pulls them along the magnetic field lines in the upper atmosphere.

Once there, the ice particles evaporate rings and water can chemically react with the Saturn's ionosphere. One result of these reactions is & # 39 increased longevity of electrically charged particles called H3 + ions, consisting of three protons and two electrons. When the supply of sunlight, H3 + ions glow in infrared light observed by O & # 39 team; Donoghue, using special instruments attached to the Keck telescope in Mauna Kea, Hawaii.

Their observations showed streaks of light in the northern and southern hemisphere & # 39; Saturn pits, where the magnetic field lines crossing the ring plane includes the planet. They analyzed light to determine the amount of precipitation of the ring and its influence on the ionosphere Saturn. They found that the amount of rain matches remarkably well with a surprisingly high values ​​obtained for more than three decades earlier Connerney and colleagues, from one area in the south of getting the most.

Command also detected a luminous band at higher latitudes in the southern hemisphere & # 39; and. This is where the magnetic field of Saturn crosses the orbit of Enceladus, a geologically active month, eliminating the geysers of water ice in space, suggesting that some of these particles to Saturn rain as well. "It was not a complete surprise," said Connerney. "We have identified Enceladus and the circlip as a rich source of water, and based on the other narrow dark bands in this old Voyager image." Geysers, first observed Cassini instruments in 2005 year, it is believed to come from liquid water ocean beneath the frozen surface tiny moon. Its geological activity and ocean water make Enceladus one of the most promising places to search for extraterrestrial life.

The team would like to see as rain ring varies with the seasons on Saturn. As the planet progresses at 29.4 years, orbit, rings exposed to the Sun in one degree or another. Since the ultraviolet radiation from the sun charges grain ice and making them react to a magnetic field of Saturn, var & # 39; iruyuchy exposure to solar light should change the amount of rain ring.

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