Scientists Propose An Icy Origin At Edge Of The Solar System For Mysterious Dwarf Planet Ceres
Ceres is classified as a dwarf planet that exists in the asteroid belt that lies between Mars and Jupiter. It is the only dwarf planet that is located in the inner solar system, and was first discovered in 1801 by Giuseppe Piazzi. It was in fact called an asteroid for many years, but because of its size and differences scientists reclassified it as a dwarf planet in 2006. While Ceres is 25% of the asteroid belts total mass, Pluto is still 14 times larger.
NASA's Dawn mission has been orbiting Ceres since March 2015. During that mission, Dawn discovered that the inner solar system's only dwarf planet was an ocean world where water and ammonia reacted with silicate rocks. According to NASA, as the oceans froze, salts and other evidential minerals concentrated into deposits that are now defined in various locations across the dwarf planet's surface.
In a research paper released recently, scientists tackle the conundrum that Ceres presents in that it is so different from its surroundings. Ceres orbits the Sun deep in the main belt, and is in close vicinity of many C-type asteroids. However, Ceres is not a C-type asteroid, but is more similar to G-type asteroids which are all hydrated. Ceres is also rich in ammonia compounds that are not usually found in C-type asteroids.
Scientists in the research paper propose another possible explanation for why Ceres is so different from its neighbors. They believe that it is possible the dwarf planet began in an orbit beyond Saturn and got planted in the asteroid belt during a massive reshuffling of planets, and has remained there to this day.
Researchers used what is considered the most common model of the early solar system, called the Nice model. It states that the giant planets of the solar system formed closer to the sun, and closer to one another, than present day locations. As planets began to drift to their current locations, it caused a bit of a disturbance. During this process, the large population of Kuiper Belt objects were disrupted and their orbits bothered by the advancement of the giant worlds. As some were ejected entirely from the solar system, others crashed into one another and were destroyed. And perhaps others made their way into the inner solar system.
Authors of the paper understand that one of the limitations to their study is that their "results are based on a single simulation from Izidoro et. al." They go on to state, "Nevertheless, this simulation represents, to our knowledge, the most successful one in reproducing the origin of Uranus and Neptune as well as of a third ice-giant planet, required in the most recent versions of the Nice model."
Top Image Courtesy of NASA