If you're struggling to come to grips with the vastness of space, maybe this video will help. In the video, we see how the sun would shrink if we were traveling away from it at the speed of light. Occasionally, at appropriate intervals, a planet shoots past.
Riding Light from Alphonse Swinehart on Vimeo.
The video lasts 45 minutes, at which point we are less than two minutes past Jupiter. Saturn is still half an hour ahead. The author, Alphonse Swinehart, didn't continue the project out to Pluto, not just because it's not a planet anymore, but because it really would take most of the day. Extend the project to the stars and we would be here for years, and through most of that time, the sun would be a barely detectable dot in the middle of the screen, with nothing else to see.
"I've taken liberties with certain things like the alignment of planets and asteroids, but overall I've kept the size and distances of all the objects as accurate as possible," Swinehart says.
The idea of seeing the universe as one would when riding a light beam isn't new. This isn't a realistic interpretation of something that could really be experienced given the right equipment, however. At the speed of light, time stops, and if one was traveling away from the sun at even close to light-speed, time would slow down and the sun would be drastically red-shifted so that we could barely see it.
However, if you want to get your head around how “really, really BIG” space is, watching the video in full could be a great way to get started.