The oldest DNA discovered reveals that 2 million years ago, the northern tip of Greenland was home to mastodons and many other animals. It also had a lush landscape, which is a stark contrast to today's barren Arctic desert.
For nearly 2 million years, Homo sapiens as well as their predecessors eschewed salad in favor of a diet heavy on meat, propelling them to the top of the food chain.
NASA's Hubble Space Telescope observed a giant comet set to approach Earth this July that could be more easily seen using a telescope. The cosmic event comes amid a new study that found a roaming star could one day cause tens of millions of comet to rain down in our Solar System.