Intriguing: is the dwarf planet Ceres made of 90% water?

Ceres, a dwarf planet located in the asteroid belt, still harbors many secrets. Recent discoveries could reshape our understanding of this mysterious celestial object.

Computer simulations suggest that Ceres is far richer in ice than previously thought. Researchers from Purdue University and NASA's Jet Propulsion Laboratory (JPL) have recently questioned the dominant hypothesis that this dwarf planet is primarily rocky.


By studying the craters on Ceres' surface, scientists have discovered that these have not deformed significantly over the past few billion years. This could indicate a substantial presence of ice mixed with rocky materials, preventing their deformation.

Simulations show that with only a small amount of rock in the ice, the craters retain their shape. Thus, Ceres may be composed of more than 90% ice, contradicting previous estimates which placed this proportion at less than 30%.

The researchers also suggest that Ceres may have once harbored a mud ocean. Over time, this ocean would have frozen, leaving behind an icy crust impregnated with rocky material. Geological formations such as pits and domes support this theory.

The team based their research on data collected by NASA's Dawn mission, which mapped Ceres' surface between 2015 and 2018. Observations also include evidence of frozen water beneath the surface, revealed by spectrographic and gravimetric data.

Ceres could thus become a key model for studying the icy worlds of the solar system. Comparable to ocean moons like Enceladus or Europa, it offers a more accessible terrain for future space missions.

According to the researchers, some of the bright structures observed on Ceres' surface could be remnants of eruptions from its former muddy ocean. This makes Ceres a prime target for future missions aimed at collecting samples.

What is Ceres?

Ceres is a dwarf planet located in the asteroid belt between Mars and Jupiter. It is the largest object in this region, with a diameter of approximately 590 miles (950 kilometers). Discovered in 1801 by astronomer Giuseppe Piazzi, Ceres was long classified as an asteroid before being reclassified as a dwarf planet in 2006.

Ceres is an object of study for researchers as it may contain clues about the formation of the solar system. Its icy surface and supposed history of a muddy ocean make it a model for icy moons like Europa (a moon of Jupiter) and Enceladus (a moon of Saturn). Ceres could thus shed light on the geological and hydrological processes on these distant worlds.