In order of distance from the sun they are; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto, which until recently was considered to be the farthest planet, is now classified as a dwarf planet.

An orbit is the path that an object takes around another object. In our solar system, the planets orbit around the Sun in a elliptical path. An “ellipse”looks like a circle that has been stretched. Gravity, a force in the universe, keeps the planets and otherobjects in space on their paths (or orbits).

Our solar system consists of our star, the Sun, and everything bound to it by gravity — the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, dwarf planets such as Pluto, dozens of moons and millions of asteroids, comets and meteoroids.

Pluto

So inconspicuous that it was not discovered until 1930, Pluto is not a gas giant planet like all the others in the outer solar system. Instead it is a small, rocky world about the size of Earth’s Moon. It seems to have a bright layer of frozen methane (“marsh gas,” chemically CH4) on its surface.

A gas giant is a large planet that is not primarily composed of rock or other solid matter. One cannot “land on” such planets in the traditional sense. There are four gas giants in our solar system: Jupiter, Saturn, Uranus, and Neptune.

It’s not quite liquid, not quite gas, but a “supercritical fluid” that shares properties of each. Your body would naturally stop falling and settle out somewhere at this level, where your density and the atmosphere’s density are equal. Still glowing white-hot, hydrogen has become so dense as to become a liquid metal.

Back in 1989, scientists sent a spacecraft to Jupiter, and it took a little over six years to reach the planet. The reason the spacecraft took so long is because it did go in a straight path from Earth to Jupiter. In 2006, another spacecraft went on a direct path to Jupiter, and this trip took a little over 13 months.

Jupiter is made of mostly hydrogen and helium gas. If you tried to land on Jupiter, it would be a bad idea. You’d face extremely hot temperatures and you’d free-float in mid-Jupiter with no way of escaping.

Roughly 300,000 kilometers (200,000 miles) from Jupiter, radiation would penetrate your suit and you’d die. This is a lot faster than you’d fall from the top of Earth’s atmosphere because Jupiter’s gravity is much stronger than Earth’s. You’ll still be able to see the sun, but don’t expect it to heat you up.