An Asteroid Approaches Your Planet: Roll a d10

It sounds like a surprise challenge posed by the “Dungeon Master” in a game of Dungeons & Dragons but this is sort of what happened on a cosmic scale on Feb. 6, 2017, when the 200-meter (656-foot) -wide asteroid 2017 BQ6 passed by Earth. Using the radar imaging capabilities of the giant 70-meter antenna at…