Download Science Journals * 3-18-13

March 24, 2014
• Remember….
• What is the smallest particle of matter that still
retains all of the properties of that matter?
• What is in the center of the smallest particle of
matter?
• What surrounds the center?
• Do you remember that the atom is mostly empty
space?
• What did we explore Friday that is mostly empty
space?
TEK 8.8B
• Recognize that the Sun is a medium-sized star
near the edge of a disc-shaped galaxy of stars
and that the Sun is many thousands of times
closer to the earth than any other star.
• Star - a large ball of gas that generates its own
energy by fusing hydrogen atoms to make
helium. It is held together by its own gravity.
This process emits a tremendous amount of
energy, and some of the energy is in the form
of light.
• Astronomical Unit (AU): The distance
between the Earth and the sun (about 150
million kilometers, or 93 million miles).
Where’s The Sun? (where’s waldo?)
1. Where is our solar system located in the Milky
Way galaxy?
2. How does the Sun’s mass compare with other
stars in the galactic neighborhood?
3. How does the distance of the Sun from Earth
compare to the distances of other stars from
Earth?
4. How long does it take for light from the Sun to
reach Earth’s surface?
Your Galactic Address
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North Ridge Middle School
7332 Douglas Lane
North Richland Hills, Tx
USA, North America
Planet Earth
Solar System
Milky Way Galaxy
Virgo Supercluster
Universe
Artistic rendering of the possible shape of the
known universe.
http://scienceblogs.com/startswithabang/upl
oad/2010/12/whats_in_the_uni
verse/WMAP.jpeg
Virgo Supercluster
SUN’S MASS
• The Sun’s mass is 199 with 28 zeros after it in
kg, and it’s a medium sized star.
• There are billions and billions of stars in the
galaxy.
• To make writing the mass of these stars easier,
the Sun is the frame of reference and the Sun
is equal to one solar mass.
• Smaller stars < one solar mass
• Larger stars> one solar mass
How Long Does it Take for the Light of
our Sun to reach us?
http://www.universetoday.com/15021/howlong-does-it-take-sunlight-to-reach-the-earth/
The LIGHT-YEAR
• A light-year is a measure of distance. It is not a
measure of time.
• A light-year is the distance that light travels in
one year.
• It is equal to about 6 trillion miles.
• 6,000,000,000,000 miles.
Science Journals – 3-25-14
• The light from Alpha Centauri A takes 4.3
years to reach Earth. The light from Ross 154
takes 9.7 years to reach Earth. The light from
Luyten 726-8A takes 8.7 years to reach Earth.
The light from Procyon A takes 11.4 years to
reach Earth. The light from Sirius B takes 8.1
years to reach Earth.
1. What is the order of the following stars from
the closest to Earth to the farthest from
Earth?
Massive Stars
• OUR SUN IS JUST AN AVERAGE SIZED STAR!
• There are stars out there much, much bigger…
Note down this definition -
Our Sun →