CNet May 2015 | The universe is a big place. Let's rephrase that. The universe is a gargantuan place. At this moment in time, astronomers believe that it measures some 93 billion light-years across.
When we look out across space, though, we're not just looking through distance. We're looking back in time. All of the light we see here on Earth is from the past, so observing something a billion light-years away means we see it as it existed a billion years ago. more>