Across the Universe: Featureless Features
At the end of September 2016, Rosetta finally ended its mission by crashing into its comet. This column, about an earlier aspect of the Rosetta mission, first appeared in The Tablet in October 2010; we first ran it here in 2016. Back in July [2010], ESA’s Rosetta spacecraft, en route to a comet rendezvous in 2014, flew past asteroid Lutetia, a 100 km pile of rock orbiting between Mars and Jupiter. The result of that encounter was a hot topic of both the European Planetary Science Conference in Rome in September and a meeting of American planetary astronomers in Pasadena in October [2010]. Studying asteroids has always been challenging. Even in the largest telescopes they’re mere dots of light, too small to show any shapes, much less surface details. We can only infer their nature from the most subtle of hints: how their brightness varies as they spin, how much infrared light they radiate, their visible and infrared colours. Minerals that contain … Continue reading →