To look up into the night sky is to gaze deep, deep into the past. Light moves fast, but not fast enough for us to get an instantaneous peek at the cosmos. So when we look at some of the glowing balls of plasma that light up our sky, we're actually seeing them as they looked thousands of years ago. Even the light from our own sun is eight minutes old before it reaches Earth.
Humanity has gotten pretty good at tracking down planets in other solar systems. Between 2009 and 2013, the Kepler telescope discovered thousands of worlds orbiting distant suns. But finding out what those exoplanets are like has been more of a challenge. Luckily, we're getting better at it.
Cassini just entered the second-to-last phase of its mission, where it will perform so-called ring-grazing orbits (shown in yellow). The blue loops represent orbits that it made previously in its nearly 20-year mission. Next year, it will enter the grand finale phase, which will end with Cassini's destruction.
"To travel in space is to be awestruck, over and over and over."--Don Pettit, Spaceborne. Don Pettit and his crewmates flew into space three times, capturing about 600,000 photos from their shuttle missions and long-term stays on the International Space Station. In his new book, Spaceborne, the astronaut/photographer highlights some of the best of the collection, leading to page after page of mind-blowingly beautiful space imagery. This is a good one for the coffee table. Popular Science's photo director, Thom Payne, chose 10 of his favorite Spaceborne images. Here are his picks, with captions excerpted from the book.