Transcript Light Year

The EARTH is
93 Million Miles
from the SUN.
Distances in our Solar System are measured in
ASTRONOMICAL UNITS (AU).
Topic: Light Years
Essential Question: How do scientists use light
years to measure distances in our universe?
Astronomical Unit (AU)
•Used to measure distances in our
solar system
• about 93 million miles which is the
Earth to the Sun
IS A MEASURE OF
A LIGHT YEAR IS THE DISTANCE
LIGHT TRAVELS IN ONE YEAR!!!
Topic: Light Years
Essential Question: How do scientists use light
years to measure distances in our universe?
Light Year
•The distance that light travels in one
year
•Light travels at the fastest speed
known in the universe
•It can go around the Earth 7 times in
1 second!
Scientist use LIGHT YEARS because
STARS are too far away from each
other to use…
Topic: Light Years
Essential Question: How do scientists use light
years to measure distances in our universe?
Light year
Scientists use light years because
stars are too far away to use: meters,
kilometers, AU (Astronomical Unit)
•One light year is 10x1016 meters long
•That’s 5.8 trillion miles!
One LIGHT YEAR is
or
1 year
1 x 1016
1 year
1 year
1 year
1 x 1016
1 x 1016
1 x 1016
1 year
1 x 1016
Five Light Years = 5 x 1016 meters
43 Light Years
from EARTH
•By the time you see the light 43 years have passed.
•The light was created before most of your parents were born.
Topic: Light Years
Essential Question: How do scientists use light
years to measure distances in our universe?
If a star is 43 light years away, that
means light has been traveling 43
years from that star to Earth
That means this light started traveling
before most of your parents were born