Solar System moons. The centaurs and many short-period comets also orbit in this region. Due to their greater distance from the Sun, the solid objects in the outer Solar System contain a higher proportion of volatiles, such as water, ammonia, and methane than those of the inner Solar System because the lower temperatures allow these compounds to remain solid. The four outer planets, or giant planets (sometimes called Jovian planets), collectively make up 99% of the mass known to orbit the Sun. Jupiter and Saturn are together more than 400 times the mass of Earth and consist overwhelmingly of hydrogen and helium.
The Magic School Bus Lost in the Solar System the book. Most notably, in the episode, Janet's bragging about herself does not appear to be empty bragging and she constantly raves about how "proof" is needed for all extraordinary claims, prompting her to force Arnold to collect "proof" from every planet in the solar system, so she can prove to the students in her class that she actually traveled to all the planets. Also in this one Arnold surprisingly suggests going to outer space himself to prove to Janet the truth. Also, instead of remaining in the asteroid belt, Ms. Frizzle uses her jet pack to fly off to