Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

The Guardian ^ | 08-10-2020 | AFP

[NRx]

The dwarf planet Ceres – long believed to be a barren space rock – is an ocean world with reservoirs of sea water beneath its surface, the results of a major exploration mission showed on Monday.

Ceres is the largest object in the asteroid belt between Mars and Jupiter and has its own gravity, enabling the Nasa Dawn spacecraft to capture high-resolution images of its surface.

Now a team of scientists from the United States and Europe have analysed images relayed from the orbiter, captured about 35km (22 miles) from the asteroid.

They focused on the 20-million-year-old Occator crater and determined that there is an “extensive reservoir” of brine beneath its surface.

Several studies published on Monday in the journals Nature Astronomy, Nature Geoscience and Nature Communications also shed further light on the dwarf planet, which was discovered by the Italian polymath Giuseppe Piazzi in 1801.

Using infrared imaging, one team discovered the presence of the compound hydrohalite – a material common in sea ice but which until now had never been observed off of Earth.

Maria Cristina De Sanctis, from Rome’s Istituto Nazionale di Astrofisica said hydrohalite was a clear sign Ceres used to have sea water.

“We can now say that Ceres is a sort of ocean world, as are some of Saturn’s and Jupiter’s moons,” she told AFP.

[Sirius Lee]

In case anybody wants to see a pic: