Did an exploding comet wipe out the mammoths?

Scientists are uncovering new clues that a cosmic explosion may have rocked Earth at the end of the last ice age. At major Clovis-era sites, researchers found shocked quartz-evidence of intense heat and pressure consistent with a comet airburst rather than volcanism or human activity. The event could have sparked massive fires, blocked sunlight, and triggered a rapid return to ice-age conditions. These harsh changes may explain the sudden loss of megafauna and the disappearance of the Clovis cul...