Thirty-two students from Western and around the world will be journeying almost two billion years back in time in a unique, intensive one-week field course to study the planet’s second-largest impact ...

CHAMPAIGN, Ill. — Two of the three largest impact craters on Earth have nearly the same size and structure, researchers say, but one was caused by a comet while the other was caused by an asteroid.

Researchers have long puzzled over what created the giant, elliptical hole called the Sudbury Basin in Ontario, Canada. At 62 kilometers long, 30 kilometers wide, and 15 kilometers deep, it’s the ...

ONE of the largest impact craters on Earth was probably caused by a comet strike rather than an asteroid. If so, the crater could have provided ideal conditions for life to flourish. Susan Kieffer and ...