I wish I could claim responsibility for this picture of Comet Schwassmann-Wachmann 3's brightest fragment passing the Ring Nebula last Sunday night, but I was sitting in the Dallas-Ft. Worth Airport at the time. Instead, it was taken by Sheldon Faworski and Sean Walker and published online at Sky & Telescope's website.
This picture also covers quite a bit of space. The comet was about ten million miles away (one light-minute, meaning light from the comet took a minute to get to Earth), the Ring Nebula is about 2300 light-years away (or 50 million times further away), and the faint galaxy IC 1296 (above and to the right of the Ring Nebula in the picture) is about 70 million light-years away, about 1.5 trillion times further away than the comet.
This picture also represents three "phases" of my own journey in astronomy. My first astronomy project was in 1986 for my 6th-grade science fair, when I researched how comets interact with the sun. My PhD dissertation was on white dwarfs, the remains of dead stars. The Ring Nebula is a star in the process of dying, and the faint star at its center is on its way to becoming a white dwarf. And finally, my work in the past few years has been on distant galaxies, much more distant than IC 1296.