One of the most enigmatic structures in the Solar System could have been created by a collision between two ice moons orbiting Saturn.
Saturn’s rings are a densely packed debris field – Image: UNIVERSE TODAY
A recent study published in The Astrophysical Journal suggests that in the “recent history” of astronomy, Saturn’s two moons collided, giving rise to the distinctive rings around the planet.
Dr. Jacob Kegerreis from NASA’s Ames Research Center humorously remarked, “It would be amazing if dinosaurs had telescopes.”
This implies that the catastrophic collision of the two mentioned moons could have occurred during the era of dinosaurs, as per NASA’s earlier calculations, Saturn’s “young” ring system is only around a few hundred million years old.
While this period might seem distant in human terms, it’s still considered “recent” in the context of astronomical history and the planet’s age of over 4.5 billion years.
According to The New York Times, the new research suggests that Saturn might have had more moons than the confirmed count of 145 today, with some potentially destroyed by collisions.
With their modest size, the two ice moons would have released a substantial amount of frigid material towards Saturn.
If this icy layer surpassed and remained beyond the Roche limit – the boundary at which a planet’s tidal gravitational forces can break apart moons – it had the potential to transform into rings.
Other fragments may have collided with other moons, causing the “victims” to break apart slightly, releasing more material.
This material could have filled the rings or coalesced to form new moons.
This could explain the youthfulness of Rhea, Saturn’s second-largest moon after Titan.
Saturn’s moon Rhea may also be the result of a collision between two moons hundreds of millions of years ago, initiating a chain of subsequent collisions – Image: NASA
Observations by NASA’s Cassini spacecraft showed that Rhea has a round and flat orbit, indicating that it is relatively recent and possibly originated from the remnants of older moons.
This is also why scientists search for life on Titan or Enceladus – the “older” moons – rather than Rhea, despite its considerable size, as a world that is too “young” may not have had enough time for life-sustaining processes to develop fully.