Mercury  Closest to the sun  Small – about the size of Earth’s moon  Covered with craters (meteorite crashes)  Almost no atmosphere  Scorching hot in the day – freezing at night  I day = 59 days  1 year = 88 days  No moons

Venus  2nd planet from the sun  About the same size as Earth  Rotates in the opposite direction  Hot and dry  Atmosphere of thick, poisonous, swirling clouds  Day = 243 days  Year = 225 days  No moons

Earth  Third planet from the sun  Largest rocky/inner planet  Only planet with liquid water on its surface  Atmosphere filters out some of the sun’s rays  Only planet in the solar system known to support life  Has one moon with almost no atmosphere and many craters  1 day = _______ hours  1 year = ________ days

Mars  Fourth planet from the sun  The “Red Planet” due to iron oxide soil  Dust storms and strong winds  Polar ice caps  Volcanoes and large canyon (10 times bigger than Grand Canyon)  Has two moons  Day = 25 hours  Year = 686 days

Asteroids  Asteroids are rocky objects up to several hundred kilometers that orbit the sun.  Some asteroids are as small as pebbles and others are so big they are called minor planets or dwarf planets.  Asteroids have uneven shapes and sometimes have smaller asteroids which orbit them.  If a large asteroid hits the earth, it causes a c_____.  Most asteroids are between Mars and Jupiter in the a_______________ b______.

Comets  A comet is a frozen chunk of ice and dust that orbits the sun.  Comets are small compared to planets.  Comets have three parts (a coma and a tail only when near the sun) 1. Nucleus (dirty snowball) 2. Coma (giant cloud of dust and gases) 3. Two Tails (goes away from the sun)