Bright spots on Ceres

Several bright surface features (also known as faculae) were discovered on the dwarf planet <a href="/facts/Ceres_(dwarf_planet)/yIVEMYtG">Ceres</a> by the <a href="/facts/Dawn_(spacecraft)/z4JeyNQB">Dawn spacecraft</a> in 2015.
The brightest cluster of spots ("Spot 5") is located in an 80-kilometer (50 mi) crater called <a href="/facts/Occator_(crater)/An1DhMSH">Occator</a>. The largest and brightest component of the cluster is in the center of the crater, with dimmer spots located towards this crater's eastern rim. Early in the orbital phase of the Dawn mission, the high <a href="/facts/Albedo/TJDRdKEB">albedo</a> of these spots was speculated to be due to some kind of outgassing, and subsequent closer images helped scientists determine that it is a material with a high level of reflection, and suggested ice and salt as possibilities. These bright features have an albedo of about 40%, four times brighter than the average of Ceres's surface.
On 9 December 2015, scientists reported that the bright spots on Ceres may be related to a type of <a href="/facts/Salt_(chemistry)/lsSKwGpn">salt</a>, particularly a form of <a href="/facts/Brine/xsN2GcLF">brine</a> containing <a href="/facts/Sulfate_minerals/AQAw1nJg">hydrated</a> <a href="/facts/Magnesium_sulfate/o3GwKEoQ">magnesium sulfate</a> (MgSO4·6H2O); the spots were also found to be associated with <a href="/facts/Clay/xnwouEkB">ammonia-rich clays</a>. Arizona State University scientists have proposed that the bright spots are best explained as resulting from briny water erupted from Ceres's interior that subsequently <a href="/facts/Sublimation_(phase_transition)/KDoKokMn">sublimated</a>, leaving behind only the salt deposits. Near-infrared spectra of these bright areas are consistent with a large amount of <a href="/facts/Sodium_carbonate/P6RHvIoK">sodium carbonate</a>, (Na2CO3) and smaller amounts of ammonium chloride (NH4Cl) or ammonium bicarbonate (NH4HCO3). These materials have been suggested to originate from the recent crystallization of brines that reached the surface from below. In August 2020, NASA confirmed that Ceres was a water-rich body with a deep reservoir of <a href="/facts/Brine/xsN2GcLF">brine</a> that percolated to the surface in various locations causing the "bright spots", including those in Occator crater.
The bright material is only millions of years old; cryovolcanism may not have stopped completely as there is evidence of hydrated NaCl, and a thin haze, observed through variation in brightness, still present today, thought to be due to sublimating ice. Ice would not last long in such warm conditions exposed to the vacuum of space, so that would suggest it is being brought to the surface to this day.

Bright spots on Ceres open-in-new

Bright spots on Ceres