Science speeds along so fast that it can be hard sometimes to know exactly what's known. So now and then its 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.
Jot down which side of the fact-fiction line you think each falls, then see the answers below. The challenge, of course, is to score a perfect 10.
1. We have strong evidence that our solar system is not the only one; we know there are many other Suns with planets orbiting them.
2. Some organisms can survive in space for years -- without any kind of protective enclosure.
3. Organisms have been found thriving in scalding water with temperatures as high as 235 degrees Fahrenheit.
4. We now have evidence that some form of life exists beyond Earth, at least in primitive form.
5. We currently have the technology necessary to send astronauts to another star system within a reasonable time span. The only problem is that such a mission would be overwhelmingly expensive.
6. All of the gas giant planets in our solar system (Jupiter, Saturn, Uranus and Neptune) have rings.
7. In the "Star Wars" films, the Imperial TIE Fighters are propelled by ion engines (TIE stands for Twin Ion Engine). While these spacecraft are fictional, real ion engines power some of today's spacecraft.
8. There is no gravity in deep space.
9. The basic premise of teleportation -- made famous in TV's "Star Trek" -- is theoretically sound. In fact, scientists have already "teleported" the quantum state of individual atoms from one location to another.
10. Tatooine, Luke Skywalker's home planet in the "Star Wars" films, has two Suns -- what astronomers would call a binary star system. Scientists have discovered recently that planets really can form within such systems.