This document defines key terms related to space and satellites. It explains that space is the region beyond Earth's atmosphere, and contains celestial bodies like planets, stars, and galaxies. Satellites can be natural or artificial; natural satellites orbit planets naturally, like the Moon around Earth, while artificial satellites are machines launched into space to orbit Earth or other celestial bodies. The document aims to teach students the differences between natural and artificial satellites.

1. SPACE AND SATELLITE
SLO’s: By the end of this lesson, students should be able to:
• define the term space.
• differentiate between natural and artificial satellites.

2. SPACE
Space is the vast 3-dimensional region that begins where the
Earth’s atmosphere ends.

3. SOME DETAILS:
• Space, also known as
outer space, is the near-vacuum
between celestial bodies. It is
where everything (all of the
planets, stars, galaxies and other
objects) is found. On
Earth, space begins at the
Kármán line (100 km above sea
level). This is where Earth's
atmosphere is said to stop and
outer space begins.

4. SOME IMPORTANT TERMS:
• Celestial bodies: a celestial body is anything floating around in space outside of
Earth.

5. • Planets: A planet is a large
natural body orbiting the
Sun (star).
• Stars: A star is a luminous
ball of gas, mostly
hydrogen and helium, held
together by its own gravity.
Sun is the nearest star to
the Earth. It represents the
most fundamental building
blocks of galaxies.

6. • Galaxies: A galaxy is a large collection of
stars, dust, and gas held together by
gravity. The smallest galaxies are known as
dwarf galaxies and can contain as few as
100 million stars, while on the other end of
the scale are massive galaxies with trillions
of stars. It is currently believed that there
are 100 to 200 billion galaxies in the
observable universe.

7. SATELLITES
• A satellite is a moon, planet or machine that
orbits a planet or star.
• For example, Earth is a satellite because it
orbits the sun.
• Likewise, the moon is a satellite because it
orbits Earth.
• Usually, the word "satellite" refers to a
machine that is launched into space and
moves around Earth or another body in
space.

8. TYPES OF SATELLITES
• There are two types of
satellites
• Natural satellites
• Artificial satellites

10. TYPES OF ARTIFICIAL SATELLITES