When reflecting on the so-called (according to NASA) reflections of light inside the Occator crater on the surface of the dwarf planet Ceres, it’s a good idea not to get too attached to the explanation. Researchers analyzing data not from the Dawn spacecraft but from a planet-hunting telescope say the lights are brightening and dimming at random times throughout the day for no apparent reasons. Is it again time to suspect aliens? While Dawn sent back stunning photos from its approach to and orbit of Ceres, there are other ways to watch it. Astronomers from the INAF-Trieste Astronomical Observatory in Trieste, Italy, used the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph at the European Southern Observatory (ESO) in Chile to observe Ceres for two nights in July 2015 and August 2015. Specifically, they watch the rotation of Ceres as is spins once every nine hours.
The result was a surprise. We did find the expected changes to the spectrum from the rotation of Ceres, but with considerable other variations from night to night.Antonino Lanza, co-author of the report in the journal Monthly Notices of the Royal Astronomical Society, says they expected to see the reflections change due to the rotation in Ceres’ position relative to the Sun, but the random changes in brightness may indicate that the material causing the lights is not hydrated magnesium sulfates (Epsom salts) , as NASA said in its latest reports on the Dawn photos, but something volatile that is affected by the heat of the Sun. Read More: Mysterious Universe