Short answers, pulled from the story.
The bright spots on Ceres are reflective surface features discovered on the dwarf planet by NASA's Dawn spacecraft in 2015. They are made largely of salt deposits left behind after briny water reached the surface and sublimated away.
The bright spots on Ceres were discovered by the Dawn spacecraft in 2015. On the 9th of December 2015, scientists reported that the spots were probably linked to a salty brine containing hydrated magnesium sulfate.
The brightest cluster, called Spot 5, sits inside Occator crater, an 80 kilometer-wide crater at 19.86 degrees north latitude and 238.85 degrees east longitude. Its central point is named Cerealia Facula, with the dimmer Vinalia Faculae spots to the east.
Near-infrared spectra show the bright spots on Ceres are made largely of sodium carbonate, with smaller amounts of ammonium chloride or ammonium bicarbonate. Earlier analysis also linked the spots to hydrated magnesium sulfate brine and ammonia-rich clays.
The International Astronomical Union approved the names Cerealia Facula and Vinalia Faculae for the bright features inside Occator crater on the 26th of November 2016. Cerealia Facula marks the central point of Spot 5, and Vinalia Faculae marks the dimmer group to the east.
In August 2020, NASA confirmed that Ceres is a water-rich body with a deep reservoir of brine that percolates up to the surface in several locations, including Occator crater. Further analysis of Dawn's low-altitude data traced the spots to melting crustal ice from an impact and to a deeper brine reservoir near Ceres's mantle.