from the queue-the-that's-no-moon-comments dept.
Saturn's moons may be significantly younger than their home planet, favoring a theory that they formed from Saturn's rings:
Freshly harvested data from NASA's Cassini mission reveals that Saturn's bulging core and twisting gravitational forces offer clues to the ages of the planet's moons. Astronomers now believe that the ringed planet's moons are younger than previously thought. [...] The Encelade team – lead by Valéry Lainey of the Paris Observatory – provided two key measurements in the research, "New Constraints on Saturn's Interior From Cassini Astrometric Data" [DOI: 10.1016/j.icarus.2016.07.014] [DX]. The scientists measured Saturn's Love number (the rigidity of a planet) for the first time and confirmed Saturnian moons move away from the planet at a faster rate than expected. (Most moons, including Earth's moon, move away from their parent planet.)
Using photographic images taken from century-old glass negatives and Cassini spacecraft observations, the group measured the Love number – named for Augustus E.H. Love, a famed British mathematician who studied elasticity – that describes the rigidity of the tidal bulge and the dissipation factor, which controls the speed at which moons move away.
While Saturn is mostly a gigantic shroud of liquid hydrogen and liquid helium, it contains a rocky core – about 18 times the size of Earth, which responds to tidal forces from all of Saturn's major moons by bulging. The forces of the bulging core, in turn, push the moons slightly away.
[...] "By monitoring these disturbances, we managed to obtain the first measurement of Saturn's Love number and distinguish it from the planet's dissipation factor," Tajeddine said. "The moons are migrating away much faster than expected." Tajeddine explains that if Saturn moons actually formed 4.5 billion years ago, their current distances from the home planet should be greater. Thus, this new research suggests, the moons are younger than 4.5 billion years, favoring a theory that the moons formed from Saturn's rings.
Related Stories
NASA's Cassini Spacecraft Ends Its Historic Exploration of Saturn
Telemetry received during the plunge indicates that, as expected, Cassini entered Saturn's atmosphere with its thrusters firing to maintain stability, as it sent back a unique final set of science observations. Loss of contact with the Cassini spacecraft occurred at 7:55 a.m. EDT (4:55 a.m. PDT), with the signal received by NASA's Deep Space Network antenna complex in Canberra, Australia.
[...] As planned, data from eight of Cassini's science instruments was beamed back to Earth. Mission scientists will examine the spacecraft's final observations in the coming weeks for new insights about Saturn, including hints about the planet's formation and evolution, and processes occurring in its atmosphere.
[...] Cassini launched in 1997 from Cape Canaveral Air Force Station in Florida and arrived at Saturn in 2004. NASA extended its mission twice – first for two years, and then for seven more. The second mission extension provided dozens of flybys of the planet's icy moons, using the spacecraft's remaining rocket propellant along the way. Cassini finished its tour of the Saturn system with its Grand Finale, capped by Friday's intentional plunge into the planet to ensure Saturn's moons – particularly Enceladus, with its subsurface ocean and signs of hydrothermal activity – remain pristine for future exploration.
Farewell, Cassini: a 20 year mission to Saturn comes to a life-protecting end
During the Jovian flyby, Cassini performed scientific observations of the planet, showing that Jupiter's cloud belts were areas of "net-rising atmospheric motion."
This observation contradicted previous hypotheses about Jupiter's dark and light belts and served to highlight differences in planetary weather systems.
During the flyby, Cassini was also able to study Jupiter's thin ring system, revealing that Jupiter's rings were composed of irregularly shaped particles that likely originated as ejecta from micrometeorite impacts with the moons Metis and Adrastea.
Cassini: The legend and legacy of one of NASA's most prolific missions
Previously:
(Score: -1, Offtopic) by Anonymous Coward on Saturday December 10 2016, @02:00PM
before losing consciousness and/or bleed out?
i am a meat Popsicle.
(Score: -1, Offtopic) by Anonymous Coward on Saturday December 10 2016, @02:17PM
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BIG BADA BOOM!
(Score: 0) by Anonymous Coward on Saturday December 10 2016, @02:29PM
If a Saturn Moon asks you how old do I look, it's a trap.
(Score: 2) by wonkey_monkey on Saturday December 10 2016, @06:49PM
Or if Saturn asks you if her Rhea looks big.
systemd is Roko's Basilisk
(Score: 0) by Anonymous Coward on Sunday December 11 2016, @06:07AM