New data collected by NASA’s Cassini mission reveals thatSaturn’s moon Phoebe has more planet-like features than previously thought. Using data from different instruments and a computer model of the satellite’s chemistry, geophysics, and geology, astronomers have concluded that, before linking her “destiny” to that of Saturn, Phoebe was what is called aplanetesimal. The findings are published in the April issue of the scientific journalIcarus.
Unlike primitive bodies like comets, Phoebe actively evolved before stagnating and taking on its current shape, explains Julio Castilo-Rogez, from NASA’s JPL Laboratory in Pasadena, California. Celestial objects like Phoebe are thought to have condensed very quickly and are the building blocks of planets. The most interesting thing is that they provide clues to scientists about what the conditions were at the time when the giant planets and their moons arose.
Saturn is surrounded by airregular moons cloud. Phoebe is the largest and orbits in the opposite direction to the rest, that is, “reverse”. The analyzes suggest that Phoebe is so different becausewas born in the first 3 billion years of the solar system’s existence and was originally porous. It was originally spherical and hot, with denser material in the center. And its average density was similar to that of Pluto. It likely stayed warm for tens of millions of years, and the heat would have allowed it to host liquid water at some point as well. It eventually cooled and drifted into the solar system during a kind of “rearrangement” to scale. Phoebe was big enough to survive this “turbulent” journey, and was captured by Saturn’s gravity as it approached this giant planet.
