big blast, say a imes typical flare, couldover certainly kill a very ion of all t basked in its gloo Bruce tsurutani of t Propulsion Laboratory, “it race in ory.”

    all t it, is “tons of conjecture and verylittle evidence.” Cooling seems to be associated  least tinctionevents—t beyond t little is agreed, includingists can’t agree, for instance,inction—t t ebrates movingonto thousands of years or in one lively day.

    One of t is so o produce convincing explanations for extinctions is t itis so very o exterminate life on a grand scale. As ill stage a full, if presumably somes Eart event sosingularly devastating? ell, first itively enormous. It struck ons. Sucburst is not easily imagined, but as James La, if you exploded one odayyou ill be about a billion bombs s of t impact. But even talone may not o  70 percent of Earth’s life, dinosaurs included.

    t meteor ional advantage—advantage if you are a mammal, t is—t it landed in a s ten meters deep, probably at just t angle, at a time and so tible. Above all t landed was made of rock rich in sulfur.

    t  t turned an area of seafloor to aerosols ofsulfuric acid. For montered to rains acid enougo burn skin.

    In a sense, an even greater question t of  70 percent of t ing at time is  survive? so irremediably devastating to every single dinosaur t existed, ell no species of toad,ne extinct in Norte creatures er?” asks timFlannery in ing preory of America, Eternal Frontier.

    In t es vanis tiloids, on, some