A new study suggests that Saturn’s rings may not be younger than the dinosaurs as recently thought, but are nearly as old as the giant planet itself, billions of years old.
Age is rings of saturn There has long been controversy. Some researchers believe these signature traits arose with saturn Formed approximately 4.5 billion years ago from icy debris left in orbit around the solar system after its birth solar system. Others believe the rings are very young and may have originated when Saturn’s gravity ripped apart comets or icy moons.
Scientists once thought one way to solve this mystery was to take a closer look at Saturn’s rings. over time, micrometeoroid — a rock smaller than a grain of sand hurtling through space — could crash into the bright ice particles that make up Saturn’s rings. The amount of dirt on your ring may be a sign of its age.
When NASA Cassini spacecraft When it arrived at Saturn in 2004, it discovered Saturn’s rings look relatively bright and clean. Subsequent analysis showed that Saturn’s rings are approximately 100 million to 400 million years old. In contrast, dinosaurs appeared in Earth They began to dominate life on land about 230 million years ago, until a cosmic impact brought their reign to a catastrophic end about 65 million years ago.
However, the study’s lead author Ryuki Hyodo, a planetary scientist at the Tokyo Institute of Science, told Space.com that “the idea that Saturn’s rings are young seems very strange in the context of the long evolutionary history of the solar system.” “Millions of years ago was the age of dinosaurs on Earth. This means that the solar system was well established and relatively stable.”
By comparison, when Saturn formed about 4.5 billion years ago, or during an era known as the Late Heavy Bombardment about 4 billion years ago, “the solar system was much more chaotic,” Hyodo said. “Many large planetary bodies are still migrating and interacting, greatly increasing the likelihood of a major event leading to the formation of Saturn’s rings.”
To reveal the age of Saturn’s rings, in the new study, Hyodo and colleagues developed 3D computer models simulating collisions between micrometeoroids and the rings. They said these impacts typically occur at speeds of about 67,100 mph (108,000 kph).
The researchers found that these rapid collisions can generate temperatures in excess of 17,540 degrees Fahrenheit (9,725 degrees Celsius), causing micrometeoroids to vaporize. This gas then expands, cools, and condenses within Saturn’s magnetic field, creating charged ions and microscopic particles.
Subsequent simulations showed that most of these charged particles either collided with Saturn, escaped its gravity, or were dragged into its atmosphere. The scientists found that the material barely contaminates the ring, leaving it relatively clean.
“A clean appearance doesn’t necessarily mean the ring is young,” says Hyodo.
Hyodo stressed that the new study does not refute Cassini’s results. “Instead, we have shown that our interpretation of the Cassini data may be wrong,” he said.
Based on the new low dimming rates Hyodo and his colleagues estimate the rings have experienced due to micrometeoroid impacts, as well as the level of contamination seen in the rings, they believe the rings may be ancient. The same process may also affect the appearance of the ring Uranus and NeptuneThey point to icy moons surrounding giant planets.
“All in all, I think Saturn’s rings are probably very old — about 4.5 billion to 4 billion years old,” Hyodo said. “As a planetary scientist studying the formation of the solar system, our results feel more natural.”
Hyodo’s colleagues are now conducting laboratory experiments simulating the impact of micrometeoroids on ice particles in hopes of supporting these results.
In addition, Hyodo is leading science teams on several Japanese planetary exploration missions, including a future mission that may be dedicated to studying Saturn’s rings more closely. “Such a mission would allow us to approach the rings much closer than Cassini did, allowing us to directly observe the impact event or collect indirect evidence to learn more about the rings’ age,” he said.
Scientists detailed their findings Published online on December 16 in the journal Nature Geoscience.