Uranus is lighter than Mars which is heavier than Uranus, Jupiter is bigger than Neptune and has more moons, and there is a rocket in space but no aliens or astronauts.

1. In space
Uranus is lighter than Mars.
Mars is heavier than Uranus.

2. There are some stars in the space.
The isn't an UFO in the space.

3. There isn't an astronaut in space.
There are two planets in the space.

4. Jupiter has got more moons than Neptune.
Jupiter is bigger than Neptune.

5. There aren't any aliens in the planet.

6. There is a rocket in the space.