1. The View From Earth

2. Comets
A comet is a small, icy celestial body that orbits around the sun.
nucleus (solid, frozen ice, gas and dust),
a gaseous coma (water vapor, CO2, and other gases)
long tail(made of dust and ionized gases). The tail develops when the comet is near the Sun. Its long ion tail always points away from the sun, because of the force of the solar wind.
The tail can be up to 250 million km long, and is most of what we see. Comets are only visible when they're near the sun in their highly eccentric orbits
Comets which pass close to the Earth are known as Sungrazers.

3. Comets

4. Anatomy of a comet nucleus: relatively solid and stable, mostly ice and gas with a small amount of dust and other solids; coma: dense cloud of water, carbon dioxide and other neutral gases sublimed from the nucleus; hydrogen cloud: huge (millions of km in diameter) but very sparse envelope of neutral hydrogen; dust tail: up to 10 million km long composed of smoke-sized dust particles driven off the nucleus by escaping gases; this is the most prominent part of a comet to the unaided eye; ion tail: as much as several hundred million km long composed of plasma and laced with rays and streamers caused by interactions with the solar wind

5. Asteroids
Asteroids are rocky or metallic objects, most of which orbit the Sun in the asteroid belt between Mars and Jupiter.
No asteroids have been observed to have atmospheres.

6. Asteroid Belt

7. The Asteroid Belt
A doughnut-shaped concentration of asteroids orbiting the Sun between the orbits of Mars and Jupiter, closer to the orbit of Mars.
Most asteroids orbit from between 186 million to 370 million miles (300 million to 600 million km or 2 to 4 AU) from the Sun.
slightly elliptical orbit
one revolution around the Sun varies from about three to six Earth years.

8. The Asteroid Belt
about 40,000 known asteroids that are over 0.5 miles (1 km) in diameter in the asteroid belt.
first one discovered (and the biggest) is named Ceres; discovered in 1801.
range in size from tiny pebbles to about 930 kilometers in diameter (Ceres).
Sixteen of the 3,000 known asteroids are over 150 miles (240 km) in diameter.
some asteroids have orbiting moons
known as planetoids