Download solar system vocab and notes

Science Vocabulary Terms: Solar System
The vocabulary quiz on these terms will be Tuesday, December 6, 2016.
1. Revolve (revolution): to travel in a closed path around an object such as Earth does as it
moves around the sun
2. Orbit: the path a body in space takes as it revolves around another body; such as that of
Earth as it revolves around the sun
3. Ellipse: the shape of Earth’s orbit that is not quite circular
4. Rotate (rotation): the spinning of Earth on its axis
5. Axis: an imaginary line that passes through Earth’s center and its north and south poles
6. Planet: a large round body that orbits the sun or another star and does not shine in
visible light, but reflects light
7. Satellite: an object that orbits a planet
8. Solar system: the region and objects that are affected by the gravity of the sun
9. Star: a large object, made of gas, that has fusion occurring in its core, causing it to give
off light
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Solar System Notes

A solar system consists of a star and the objects that orbit around the star. A star is a
large object made of gas. Our solar system has eight planets that orbit the Sun. A planet is
a large object that orbits a star. The planets are held in their orbits around the Sun by the
force of gravity between each planet and the Sun. The average distance between Earth and
the Sun is one astronomical unit.

The planets in order from the Sun are:
1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune

Inner planets:
The four inner planets are Mercury, Venus, Earth, and Mars. These planets have
surfaces made of rock, and they are known as terrestrial planets. They have few or no
moons, and none of the inner planets have rings.

Outer planets:
These planets are located beyond the asteroid belt separating Mars and Jupiter. The
outer planets are Jupiter, Saturn, Uranus, and Neptune. These planets are made
mostly of gas, and are often referred to as “gas giants.” They have a metallic core and
a thick atmosphere. They are much larger than the inner planets, and their orbits are
much farther apart than the orbits of the inner planets. ALL outer planets have rings
and many moons. Days are very short because the outer planets rotate very rapidly.

All but two planets in our solar system have one or more moons. A moon is a natural object
that orbits a planet; it is a satellite. An object that orbits a planet is called a satellite. A
satellite can be a natural or a man-made object.

Earth makes one revolution, one complete trip around the Sun, in 365 ¼ days (one
year).

The path Earth takes around the Sun is called its orbit. Earth orbits the Sun in a counterclockwise motion. Earth’s orbit, or path, is shaped like an ellipse. An ellipse is a shape that is
not quite a circle.

As Earth revolves around the Sun, it also rotates, or spins. Earth rotates one complete
time in 24 hours (one day). Earth rotates counter-clockwise.

Earth rotates on its axis. The axis is an imaginary line that passes through Earth’s core and
the North and South Poles. Earth’s axis is tilted at a 23.5 angle.

Earth’s tilt on its axis and the counter-clockwise revolution around the Sun creates
seasons. Each season is three months long.

The Moon goes through its eight phases about every month (29.5 days) as it rotates.
The eight phases are:
1) New Moon
2) Waxing Crescent
3) First Quarter
4) Waxing Gibbous
5)
6)
7)
8)
Full Moon
Waning Gibbous
Last Quarter
Waning Crescent