1. Celestial Objects in Space
Lesson 4a
Celestial Objects in Space

2. Comet Shoemaker-Levy 9 hit Jupiter in 1994.
chunks of frozen gases, rock & dust that orbit the sun
tail is formed when the comet comes close to the Sun
Comet Tails – the white tail is sunlight reflecting off the particles that have been released; the blue tail is made of gases (ion or gas tail)
Comet Shoemaker-Levy 9 hit Jupiter in 1994.

3. Asteroids Irregular shaped rocky objects
many orbit around the Sun and this is called an asteroid belt
Left over from the formation of the solar system

4. Meteors & Meteorites
A meteoroid is a clump of rock or metal which is pulled towards Earth by gravity
In Earth’s atmosphere it heats up, begins to glow and becomes a meteor
If the object is not vaporized before it contacts the Earth’s surface it is called a meteorite
meteoroid
meteor
meteor shower

5. What’s the difference? Asteroid: Small; inactive
made of rock, carbon or metal
- Orbits the sun
Comet:
small; sometimes active object
made of dirt, gas and ice
Meteoroid:
small particle from an asteroid or comet
orbits the sun
Meteor:
- A meteoroid that burns up in the Earth's atmosphere - a shooting star.
Meteorite:
- A meteoroid that survives its passage through the Earth's atmosphere and impacts the Earth's surface.

6. Moons/Satellites Large natural objects which revolve around a planet
many planets have more than one moon
Earth’s moon has no atmosphere and has hills/valleys/craters
after the invention of the telescope Galileo saw 4 moons of Jupiter
Moons can come in a variety of size and with a variety of surfaces

7. Stars
A STAR is a luminous ball of plasma that is held together by gravity.
What is the nearest star to Earth?
What is the nearest star to the Sun?

8. Binary Solar System

9. Stars Polaris pole star for the Northern Hemisphere
390 light years from Earth
part of a binary star system
Sirius
the brightest star in the sky (70 times more luminous than the sun)
8.6 light years from the Earth
Betelgeuse
one of the brightest stars in the sky
supergiant
1,000 times bigger than the Sun but cooler than the Sun

10. Outside our Solar System
Voyager I, Pioneer 10 & 11 and Voyager 2 built to explore outside our solar system
Took 20 years to leave solar system
will reach the nearest star in years

11. video
Bill Nye- Comets and Meteors