Car safety experts just pulled off a first-of-its-kind remote controlled multi-vehicle pile up. Now investigators are put to the test as they analyze the data and look for insights into driver behavior and vehicle design.

What really happens in a multi-vehicle pileup? A first-of-its-kind experiment aims to stage a high speed crash to gain new insights on car safety. But how can they create and study a complex collision without putting any lives in danger?

The rocky planets—Mercury, Venus, Earth and Mars—were born of similar material around the same time. Yet only one of them supports life. Were Earth's neighbors always so extreme? And is there somewhere else in the solar system life might flourish?

Mars was once a blue water-world studded with active volcanoes. But when its magnetic field and protective atmosphere faded, it became the frozen desert planet we know today. With so many necessary elements in place, did life ever form on Mars?