Chandra Sees Titan's X-Ray Shadow - Universe Today
The Chandra X-Ray Observatory captured a rare event in January when Saturn's moon, Titan, passed in front of the Crab Nebula. The large moon was illuminated by the X-rays from the nebula, so it cast a shadow. This allowed astronomers to measure its atmosphere in the X-ray spectrum to be about 880 kilometres thick. This might be the first transit of Titan over the Crab Nebula since it was formed from a supernova explosion in 1054.