Inner Planets
Mercury
Named after the Greco-Roman messenger of the gods because it has the fastest orbit.
Orbits the sun in 88 Earth days.
Often difficult to observe because it travels close to the sun.
Temperatures during the day are hot enough to burn any metal.
Temperatures during night drop to -291°F (-180 °C).
It has the largest temperature range of all the planets.
Venus
Named after the Roman goddess of love.
Often mistaken as a star.
The brightest object in the night sky, besides the moon.
Its dense cloudy atmosphere hides its surface from even the most powerful telescope.
The atmosphere would be deadly to humans.
Its atmosphere is made up of a mixture of carbon dioxide and sulfuric acid that causes an extreme "greenhouse effect," in which heat is trapped by the atmosphere.
Earth
Our Home.
The only planet in the solar system capable of supporting advanced life.
Has 5 layers of atmosphere.
The atmosphere acts like a blanket, evening out temperature extremes and keeping warmth in.
Without this "greenhouse effect," Earth would be about 60°F (33°C) cooler on average.
Mars
Appears pale orange in the night sky.
The Babylonians, Greeks, and Romans all named it after their gods of war.
Only half the size of Earth.
Still has a 24-hour day.
Also has polar ice caps and an atmosphere, like Earth.
