oid—troy a city. tive tiddlers in Earts isalmost certainly in to track.

    t one  spotted until 1991, and t er it  iced as it sailed past us at a distance of 106,000 miles—in cosmic termst of a bullet passing t toucer, anot larger asteroid missed us by just 90,000 miles—t pass yetrecorded. It, too,  seen until it  warning.

    According to timoting in times a iced.

    An object a  be picked up by any Eartelescope untilit  a fe is only if a telescope o be trained on it,. ting analogy t is al tively searceroids is feaff of a typical McDonald’srestaurant. (It is actually some mucrying to get people galvanized about tential dangers oftem, anot——lyunfolding in Italy  from t Doy Laboratory atColumbia University. In ter Alvarez taccione Gorge, near to divided t layers of limestone—onefrom taceous period, tertiary. t knoo geology ast boundary,1and it marks time, sixty-five million years ago, wly vanishe fossil record.

    Alvarez   a ter of an inc could account for sucic moment in Eartory.

    At time tional  tinction  ury earlier—namely t t overmillions of years. But ted t in Umbria, if1It is Kt rat because C ed for Cambrian. Depending on a or German Kreide. Botly mean “c Cretaceous means.

    noely in tests existed for determining  migaken to accumulate.

    In t certainly  t, but luckily ion to someone outside  nuclear p;tac to rocks, but trigued  occurred to  t lie in dust from space.

    Every year tes some ty tric tons of “cosmicsp in plainer language—