It appears the mystery as to what that bright spot on dwarf planet Ceres is has been solved, with sodium carbonate the likely composition. How it got there, though, is fascinating.
Ceres has emerged as one of the most popular dwarf planets in our solar system – far behind Pluto of course, yet still ahead of any other rivals.
An image of Ceres that emerged last year set tongues wagging, as a bright spot was visible on its surface. More images emerged and the bright spot remained, located at the centre of the mysterious Occator Crater.
Many theories cropped up – mostly of the salt variety – and, according to a new paper in Nature, it is actually a mound of sodium carbonate.
Indeed it’s the highest concentration of carbonate materials ever seen outside Earth – something which could change when Juno peers beyond the clouds of Jupiter next week.
Once sodium carbonate was established as the make-up, how it got there became the new mystery and, rather than deposits from a meteorite impact, NASA reckons something else is going on.
Claiming the deposit could not have come from a passing meteorite, the space agency instead suggests hydrothermal activity, which would mean the temperature in the core of the dwarf planet is higher than first thought.
“The minerals we have found at the Occator central bright area require alteration by water,” said Maria Cristina De Sanctis, lead author on the study.
“Carbonates support the idea that Ceres had interior hydrothermal activity, which pushed these materials to the surface within Occator,” she said, with suggestions that the meteor that created the crater played a key role in bringing the material up from below.
De Sanctis’ findings of ammonia-bearing salts hints that Ceres was formed beyond Neptune in the outer reaches of our solar system, before migrating towards its current location between Mars and Jupiter.
All this info comes on the back of the successful Dawn mission to monitor Ceres last year. The below simulated overflight shows the “wide range of crater shapes” encountered, said Ralf Jaumann, a Dawn mission scientist at the German Aerospace Centre, which helped create the animation.
“The viewer can observe the sheer walls of the crater Occator, and also Dantu and Yalode, where the craters are a lot flatter.”