Space

3. The roadway of a planet. The path every object has to follow.
6. A group of stars. Some of the biggest objects in the Universe.
8. One of the most impressive machines sent to space more than a decade ago. Took a while to fix the first time. We still marvel at its pictures.
9. Object or body that orbits around a planet.
10. It's the upside-down planet. It doesn't spin the way it should. It's blue-green, we still don't really know why (or why it's tilted, for that matter).
12. Massive planet, it should have been the Sun's sister star. Good for us it's actually a failed star.
14. Jewelled crown of the Solar System. If you count its rings, it's the biggest planet in the Solar System.
15. The closest natural, space object to Earth. It seems like Armstrongs have a thing for pioneering.

1. The red planet. For a long time, we thought aliens were up there! We've sent so many robots up there, we've got entire maps of the planet.
2. Latest object we landed on. The most interesting Saturnian moon. It even has lakes!
4. Used to be a planet, but lost its status in 2006. It wasn't big enough (among many other reasons!).
5. Its blue colour is reminiscent of the sea. It's named after the god of the sea because of its blue hue. Weather forecast: VERY stormy.
7. Big rock that travels through space. The dinosaurs didn't see it coming.
11. Very hot, no atmosphere, a bit plain. Burnt its wings (it flew too close to the Sun).
13. Deadly Earth twin. Very similar in many ways, but the weather is a bit extreme. The Russians almost "conquered" it, but a camera cap doomed the mission.
14. Closest star to Earth. If it were to suddenly disappear, we'd know about it 8 minutes later. Flares up very often.