astronomy Étienne Trouvelot's 19th century astronomical drawings compared to NASA photos Rob Beschizza
astronomy What was the mystery object in space that blocked the light of a star for more than six months? David Pescovitz
astronomy Later this month, look up to see Jupiter and Saturn appear closer together than they've been since the Middle Ages David Pescovitz
asteroid Asteroid samples escaping from overstuffed NASA probe Osiris-Rex that grabbed lots of Bennu rubble Xeni Jardin
billions and billions Watch a young Carl Sagan's first TV documentary, "The Violent Universe" (1969) David Pescovitz
