Presenting... Space!

By Allison Poskey

First Off.. The Planets!

There are eight planets in our Solar system, and they all orbit the sun. The Sun is the center of our Solar System. The order of the planets from the middle out is

  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune

The planets orbit the Sun because of gravity, the Sun's gravitational pull keeps the planets in orbit. The further away from the Sun the less gravity a planet would have, and vice versa. The mass of a planet can also effect the gravitational pull from the Sun. The greater mass of a planet will have a stronger gravitational pull, and vice versa. So for example, if we were to go to Neptune, since it has a larger mass than Earth we would have a very hard time to move at all.

Rotation and Revolution

Revolution Period-

Mercury- 24 Earth years

Venus- .62 Earth Years

Earth- 365 days 5 hours (One Earth day)

Mars- 1.9 Earth years

Jupiter- 12 Earth years

Saturn- 29 Earth years

Uranus- 84 Earth years

Neptune- 165 Earth years

Rotation Period-

Mercury- 59 days

Venus- 243 Earth Days

Earth- 24 hours (One Earth day)

Mars- 1.03 Earth days

Jupiter- .41 Earth days

Saturn- .43 Earth days

Uranus- 3/4 of an Earth day

Neptune- .67 Earth days

The Inner Planets

The first four planets are known as "The Inner Planets" they are the planets that are closest to the Sun. The inner planets are

  • Mercury
  • Venus
  • Earth
  • Mars

These planets are sometimes called the terrestrial planets because of their closeness to Earth, and they have rocky, solid bodies. These Inner Planets have thin atmospheres, and they have very few moons.

The Outer Planets

The four "Outer Planets" are the planets that are the farthest away from the Sun. The Outer planets are

  • Jupiter
  • Saturn
  • Uranus
  • Neptune

These Outer Planets are very large, much larger than Earth. These planets have strong gravities, and many moons and rings. Unlike Earth these planets are mostly made up of gases, and so the nickname Gas Giants was given.

Galilean Moons

Galilean Moons were discovered by Galileo in 1610. Galilean Moons are the four largest moons orbiting Jupiter. They are named after the lovers of Zues. Their names are

  • Io
  • Europa
  • Ganymede
  • Callisto

Galilean Moons helped to disprove the theory that Earth was the center of the solar system. Galilean Moons also helped to show the importance of telescopes as a tool for astronomers.

Asteroids, Comets, and Meteors!


Most asteroids are very small, but a handful of them can get to be quite large. One called Ceres is considered to be a dwarf planet, which is what Pluto is! A ring of asteroids lies beyond the orbit of Mars.


Comets are made up of bits of rock, and dust mixed with frozen compounds. Comets are frequently found in deep space, on their way toward, or from the Sun in lengthy elliptical orbits. Their orbits can take dozens or even thousands of years to complete only one orbit. The Sun's energy blows comet material away, so that the "tail" faces the Sun.


The difference between meteors and asteroids is size, a meteoroid compared to an asteroid is like sand to a boulder. Meteors are constantly shooting in outer space, and are pulled in by the gravity of other planets and moons. They streak through the object's atmosphere becoming a meteor, and if it doesn't burn up entirely, and ends up striking the surface, then it would be called a meteorite.