Saturn’s icy rings may be much older than they appear, as they are resistant to contamination from collisions with rocky debris.
Hyodo others. This suggests that the apparent youthfulness of Saturn’s rings may be due to resistance to pollution, rather than an indication that they were formed at a young age. Image credits: NASA / ESA / Hubble / A. Simon, NASA Goddard Space Flight Center / MH Wong, University of California, Berkeley / OPAL team.
Saturn’s rings were once thought to be ancient, perhaps forming at the same time as Saturn itself, about 4.5 billion years ago.
Over time, it is thought that the rock and ice particles that make up the ring become dirty and darkened by micrometeorite impacts.
However, when NASA’s Cassini spacecraft reached Saturn in 2004, it observed that Saturn’s rings appeared relatively bright and clean.
“According to the hypothesis that non-icy micrometeorite impacts act to darken Saturn’s rings over time, Saturn’s rings are estimated to be approximately 100 million to 400 million years old. “Cassini observations show that the particles in the rings appear to be relatively clean,” said Dr. Tatsuki Hyodo of Tokyo University of Science and colleagues.
“These younger age estimates assume that the rings formed from pure water ice particles with high accretion efficiency impacting non-ice micrometeorite material.”
In the new study, researchers used a computer model to simulate the collision between a micrometeorite and an ice ring particle.
They found that high-velocity collisions can cause the micrometeorite to evaporate, and that vapor can expand, cool, and condense in Saturn’s magnetic field to form charged nanoparticles and ions.
The researchers’ simulations showed that these charged particles could either collide with Saturn, be dragged into the atmosphere, or escape Saturn’s gravity altogether.
As a result, scientists suggest that little of this material builds up on the rings, keeping them relatively clean.
They say very low pollution levels mean Saturn’s rings are actually billions of years old and are simply maintaining a more youthful appearance. suggests that it is possible.
Although more research is needed, this process may also occur in the rings of Uranus and Neptune, as well as in the icy moons around the giant planets.
“High-velocity collisions leading to the production of charged nanoparticles and ions could potentially occur in places such as the rings of Uranus and Neptune or the icy moons around the giant planets,” the authors said.
“While this mechanism may not change the bulk composition of the impacted target, it suggests that the surface composition may change.”
“Furthermore, the new material from the impactor may not be efficiently incorporated into the satellite’s rings or surface and may be transported elsewhere.”
“Thus, most of the compositional differences observed in the various ring systems of giant planets may be due to their formation processes, for example when building materials come from outside the system, rather than to their post-formation dynamics.” There is a sex.”
of study Published in this week’s magazine natural earth science.
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Takashi Hyodo others. Pollution resistance of Saturn’s ring particles during micrometeoroid impact. nut. earth sciencepublished online on December 16, 2024. doi: 10.1038/s41561-024-01598-9
Source: www.sci.news
