image: Recipe to produce an artificial cometary surface in the laboratory. Ice-dust particles are put under vacuum and low temperature. Ice sublimates, leaving a porous dust layer on the surface. This material relates to a paper that appeared in the 13 March issue of Science, published by AAAS. The paper, by O. Poch at Université Grenoble Alpes in Grenoble, France, and colleagues was titled, "Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids." view more
Credit: [Credit: Poch <em>et al. Science</em> (2020)]