A study has looked at the enigmatic bright spots on Ceres, which continue to be a source of mystery, finding that they may all have a common origin. The study, led by Ernesto Palomba from the National Institute for Astrophysics in Rome, is published in Icarus. Looking at the light reflected by the bright spots, the researchers attempted to find differences between them.
The bright spots – regions of the surface much lighter than the surrounding material – were first spotted by the orbiting Dawn spacecraft in 2015. Since then, a number of theories for their formation have been proposed, from evaporating ice to geysers.
While we can't say for certain what formed them, the leading theories at the moment are either cryovolcanoes leaving salt deposits (sodium carbonate) behind or heat from impacts melting material underground. Lending credence to the latter is the fact that 90 percent of bright spots are found in impact craters or are debris from them, notes New Scientist.
But there are hundreds of bright spots on Ceres, some with different materials in them. The team wanted to know if they all had the same formation process. The answer at the moment appears to be “yes”.
The researchers found that most of the bright spots were made of the same material – calcium or magnesium carbonates mixed with ammonia-rich clay. However some, like the brightest spot of all in Occator crater, have more sodium carbonate. This suggests they have followed different evolutionary paths.
“Each bright spot could have followed a single evolutionary path,” the team noted in their paper. “Our results highlight that the bright spots on Ceres show not only different spectral, and consequently compositional, properties but they even suggest evolutionary process involved in their differentiation”
The largely similar compositions suggest they had a common origin, before diverging and appearing slightly different today. This question still remains, but researchers now hope to build a computer model of Ceres to find an answer. In the future, it may even be worth sending robotic landers to explore the regions to see if Ceres is some sort of habitable oasis.
[H/T: New Scientist]