Ceres has a couple of bright spots that have been the reason of intrigue ever since they were found and a new study has shed light on the age of one of these bright spots – the Cerealia Facula.
This bright spot at the centre of Ceres’ Occator Crater is approximately 30 million years younger than the crater itself and this finding suggests that the bright spot is just 4 million years old – a toddler in astronomical terms.
A team of astronomers led by Andreas Nathues at the Max Planck Institute for Solar System Research (MPS) in Gottingen, Germany, studied data from NASA’s Dawn spacecraft to analyze Occator’s central dome in detail. The data was collected by Dawn’s framing camera, and the visible and infrared mapping spectrometer. The team concluded that the bright spot in the central part of the Occator Crater is only 4 million years old and that’s quite recent in terms of geological history.
Further the finding also supports earlier interpretations that suggested that the reflective material that forms the bright spot is made of carbonate salts; however, the team didn’t confirm any particular type of carbonate that have been identified in previous studies.
Authors of the latest study published in the Astronomical Journal also reveal that the smaller bright areas of Occator crater known as Vinalia Faculae are made up of a mixture of carbonates and dark material.
Researchers were also able to determine that Occator’s bright dome likely rose in a process that took place over a long period of time and didn’t form in a single event. Scientists believe that the initial trigger was the impact that dug out the crater itself, causing briny liquid to rise closer to the surface. Water and dissolved gases, such as carbon dioxide and methane, came up and created a vent system. These rising gases also could have forced carbonate-rich materials to ascend toward the surface. During this period, the bright material would have erupted through fractures, eventually forming the dome that we see today.
Currently the Dawn spacecraft is on its way to a high-altitude orbit of 12,400 miles (20,000 kilometers), and to a different orbital plane. In late spring, Dawn will view Ceres in “opposition,” with the sun directly behind the spacecraft. By measuring details of the brightness of the salt deposits in this new geometry, scientists may gain even more insights into these captivating bright areas.