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

– Closest to the sun – Rocky Surfaces – Smaller than outer

planets – None has more

than 2 moons

• Outer Planet– 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.