An article published in the journal “Nature Astronomy” reports the results of a new study on the exoplanet WASP-121b, an ultrahot Jupiter considered one of the planets with the most extreme conditions known. A team of researchers led by Tom Evans, today at the Max Planck Institute for Astronomy in Heidelberg, Germany, used data collected by the Hubble Space Telescope to investigate compounds present in WASP-121b’s atmosphere. The conclusion is that there may be clouds of iron, titanium, and corundum, the crystallized form of aluminum oxide that makes up rubies and sapphires.