The tiny glass beads at the top of this image (shown with an Australian coin for scale) suggest that a large space rock slammed in Earth near Australia about 11 million years ago. The impact could have gouged a crater up to 15 miles wide, although no trace of such a depression has yet been found. The bottom half of the image shows microscopic view of slices of the beads, known as tektites, at the top. [Musolino, et al./Science]
Find out more in our radio program entitled Informative Beads.