It has been 38 years since Halley's Comet last passed through the inner solar system. This famous comet takes roughly 75 years to circle the sun. But if you're 42 years old or younger, you probably have little or no memory of the 1986 appearance of this famous cosmic vagabond (your next chance will come in the summer of 2061).
Or maybe, if you were around back then, you didn't see Halley at all because of light pollution or the comet's low altitude above the horizon. If you missed out on the 1986 event, or don't want to wait until 2061, you might want to step outside before sunrise during these next few mornings and try to catch a view of some "cosmic litter" that has been left behind in space by Halley's Comet.
