Transcript Physical Attributes of Stars

Our Solar System
S4E1. Students will compare and contrast the physical attributes of stars, star patterns, and planets.
a. Recognize the physical attributes of stars in the night sky such as number, size, color and patterns.
b. Compare the similarities and differences of planets to the stars in appearance, position, and number in the
night sky.
c. Explain why the pattern of stars in a constellation stays the same, but a planet can be seen in different
locations at different times.
d. Identify how technology is used to observe distant objects in the sky.
S4E2. Students will model the position and motion of the earth in the solar system and will explain the
role of relative position and motion in determining sequence of the phases of the moon.
a. Explain the day/night cycle of the earth using a model.
b. Explain the sequence of the phases of the moon.
c. Demonstrate the revolution of the earth around the sun and the earth’s tilt to explain the seasonal changes.
d. Demonstrate the relative size and order from the sun of the planets in the solar system.
How does the Earth and its
Moon Move?
• The Earth rotates or spins on its axis
• It takes 24 hours! That’s why we have day
and night
• It also revolves or orbits around the sun
• A complete revolution takes about 1 year!
Seasons
• Do you know why we experience seasons?
• It’s because of the Earth’s tilt!
The Moon
• Why does the moon seem to change?
– The moon orbits Earth and it takes about
1 month!
– During its orbit, we see reflected light from the
sun
Moon Phases
• As the moon revolves around Earth, we
see different phases
The Moon
• Moon phases on a
calendar
Solar System
• A solar system is a group of objects in
space that orbit a star
• Objects include: inner and outer planets,
dwarf planets, moons, and asteroids
The inner planets are closest to the sun:
Solar System
• The asteroid belt separates the inner and
outer planets
• The outer planets (gas giants) are farthest
from the sun
Inner and Outer Planets
• Inner Planets
• Outer Planet
– Closest to the sun
– Rocky Surfaces
– Smaller than outer
planets
– None has more
than 2 moons
– Bigger than inner
planets
– Made up of mostly
gases and called
the “gas giants”
– Many moons
– Rings made of dust
ice, or rock
A glance at our Solar System
What is a Star?
•A star is a huge ball of
super heated gases
Studying Stars
• Scientists study stars to learn about our
solar system
• Scientists group stars using their
similarities and differences
Star Color
• Rising temperature of
a star means it is
changing color
– Star color tells us how
hot the star is
– They can range from
red, to orange-yellow,
white, and to bluish
white
Star Color
• Blue Stars are the
hottest
• Red Stars are the
coolest
Star Brightness
• How Bright a star looks depends on
– How far it is from Earth
Star Size
• Dwarfs: Small up to 20 times larger than our sun and
up to 20,000 times brighter. Our sun is a dwarf star
• Giants: Old and large
• Super giants: Older and larger
• Virtually non-existent: Used to be other stars
but are slowly burning out
Our Sun
• Our Sun is a star which is also the center
of our solar system!
• It is the largest object in our solar system
• Without it no life on Earth could exist
Our Sun
• Made up of gases, mostly hydrogen and
helium
• Is a medium sized yellow star
• It has medium heat, brightness and size
Groups of Stars
• A Constellation is a group of stars that make
an imaginary picture.
• A galaxy is a huge system of gases, dust,
and stars.
• The universe is everything in space.