Solar system part 2

� 3 substances that make up the

planets are gases, rock, and ices.
(classification is based on melting
points)

� H (Hydrogen)and He (Helium)are the

gases on most planets

Interior of the planets

� Rocks are mainly silicate minerals

and metallic iron, which have
melting points above 700C

� Ices include ammonia, methane,

carbon dioxide, and water.

interior continued

� Terrestrial planets are dense, consisting

mostly of rocky and metallic substances,
and only minor amounts of gases and ices.

� Jovian planets contain large amounts

of gases (H and He) and Ices (water,
ammonia, and methane)

�

Terrestrial vs Jovian
planets

Astronomical Units (AU) are
measurements used within our Solar
system based off of the distance
between the Earth and Sun. 93.6
million miles ( 150 million km)

Astronomical Units

AU’s versus Lightyears

Light years: used to measure distances
of the stars and other objects outside
our solar system:
1 lightyear = 5.88 trillion Miles (9.46
trillion km)
A lightyear is how far light can travel in
one year.

Astronomical Measurements

Light years

� Light can orbit the Earth 7x in one

second at the Speed of Light

� The Milky Way Galaxy: 100,000 light

years!

�

Speed of light: 186,000m/s