Download ASTRONOMY

WHAT IS IT?
• The study of the night sky and the
celestial objects that exist.
Let’s take a vacation to….
• If we could travel at the speed of light,
300 000 000 m/s (or 300 000 km/s)
• Note: Sound travels at 300 m/s
It would take 1 s to get to the
8 minutes to get to the
4 light years to get to
2.5 million light years to get to
• http://www.youtube.com/watch?v=HEhe
h1BH34Q&feature=related
• http://www.youtube.com/watch?v=HEhe
h1BH34Q&feature=related
ASTRONOMY
• The study of the night sky and the
CELESTIAL objects that exist.
• CELESTIAL means sky.
Astronomy
• The study of the night sky and the
CELESTIAL objects that exist.
• CELESTIAL means sky.
UNIVERSE
• All MATTER and ENERGY that exist
everywhere.
CELESTIAL OBJECTS:
•
•
•
•
Sun
Moon
Planets
Stars
OUR SOLAR SYSTEM
• The system of planets and other objects
that orbit the Sun in a circular pattern.
• The force of GRAVITY is a force of
attraction between masses.
• The Sun has a very large mass and
therefore a strong force of gravity that
pulls on the Earth and the other planets,
keeping them in orbit.
INNER PLANETS
Mercury
Venus
Earth
Mars
OTER PLANETS
Jupiter
Saturn
Uranus
Neptune
Remember the planets
My very Excited Martian just sent us
nachos 
Planets move in 2 ways:
1. ORBITAL PERIOD  the length of
time required to orbit the Sun.
Eg) Earth’s orbital period = 365.25
days (1 year = 365 days, every 4 years
we have a leap year)
2. ROTATIONAL PERIOD  the length of
time required to rotate on its axis (like a
globe)
Earth’s Rotation Period =
____________
http://www.youtube.com/watch?v=lkWyMM8o0c&feature=related
http://www.youtube.com/watch?v=R2lP14
6KA5A&feature=related
• http://www.explorelearning.com/index.cf
m?method=cResource.dspView&Resour
ceID=441
The Reason for the Seasons
• http://www.youtube.com/watch?v=DuiQv
PLWziQ&safety_mode=true&persist_saf
ety_mode=1
• Hmmmm…..
Summary
• It is because of Earth’s tilt. It is tilted
23.5 degrees from the vertical. In the
summer, the northern hemisphere is
tilted towards the Sun and receives more
direct sunlight making it warmer. In the
winter, the N.H. is tilted away from the
Sun and receives less sunlight making it
cooler.
THE SUN
• Closest star to Earth.
• It is important because it
supports life.
• Provides us with HEAT and
LIGHT, and plants use the
energy from the Sun to make
FOOD and OXYGEN.
• Made up of the gases
HYDROGEN and HELIUM.
ASTEROIDS
• “Large, space rocks” that orbit the Sun.
• Found in the ASTEROID BELTbetween
Mars and Jupiter.
• Range in size (diameter) from a grain of
sand to 500 km.
• Composed of elements: Iron, carbon,
and nickel
An Asteroid (NASA)
Meteor Sighting
• http://www.youtube.com/watch?v=CgQS
x-CO8C8&NR=1
• http://www.cbc.ca/technology/story/2008/
11/28/meteorite.html
• http://www.youtube.com/watch?v=18Glk
V73VjI
What came first?
2
3
Hoba – Africa,
largest meteorite
(60 tons), 80 000
years ago,
About 3 m X 3 m
1
http://www.meteorcrater.com/
METEOROIDS, METEORS,
METEORITES
• Meteoroids – small “space rocks” that
move through space.
• They enter Earth’s atmosphere  rub
against gas particles in the atmosphere
 become very hot  burn up. They
can be seen as a flash of light in the
night sky, often called “SHOOTING
STARS” or METEORS.
• If they are large enough they will not
completely burn up and a METEORITE
will be left on Earth. Sometimes it can
make a CRATER from its impact.
METEOROITES, METEOROIDS,
METEORS
• A METEOROID  a lump of rock
smaller than an asteroid that gets pulled
into Earth’s atmosphere.
• METEOR  As it travels through the
Earth’s atmosphere, friction with
particles in the air causes it to burn up.
If it is large enough we can see a flash of
light from Earth, also called a
“SHOOTING STAR”
• METEORITE  any part of the
meteoroid that survives and lands on
earth. Large meteorites can leave
behind huge holes called craters.
COMETS
• Chunks of ice, dust and rock that travel
in long, oval orbits around the Sun.
• Referred to as dirty Snowballs.
• As they near the Sun, the heat from the
Sun vapourizes the frozen gases and
dust, and the solar wind pushes them
out creating a long, colourful tail.
• The glowing tail can be seen for months.
Scale Diagram
• http://www.exploratorium.edu/ronh/solar
_system/