Science speeds along so fast that it can be hard sometimes to know exactly what's known. So every now and then, it's helpful to pause and ponder the state of things.
The following 10 statements straddle the line between fact and fiction in space science. If you haven't been paying very close attention, the truthfulness of some might be hard to gauge.
After you've submitted your answers for scoring, follow the Web links to learn more about science fact and fiction from Space.com.