Lesson 39
Size of Universe
Size of Universe
Lesson 40
What is Light?
What is Light?
Lesson 41
The Moon
The Moon
Lesson 42
Moon Phases
Moon Phases
Lesson 43
Earth's Seasons
Earth's Seasons
Lesson 44
Life Cycle of Stars
Life Cycle of Stars
100
This unit is used to measure vast distances in space.
Light year
100
These are the the tiny particles that carry light energy are called these.
Photons
100
The Moon is classified as this type of object.
Natural satellite
100
This phase occurs when the Moon is between Earth and the Sun.
New Moon
100
What causes the different seasons on Earth?
It's tilted axis.
100
Stars begin forming inside giant clouds of gas and dust called these.
Nebula
200
The Milky Way is classified as this type of galaxy.
Spiral
200
Astronomy depends heavily on observing this.
Light
200
What size is the Moon compared to the Earth?
1/4th the size
200
What causes the phases of the Moon?
The Moon’s position relative to Earth and the Sun
200
What degree is Earth tilted?
23.5 degrees
200
Which stage of a star’s life lasts the longest?
Main sequence
300
How many miles make up 1 light year?
Approx 5.8 trillion
300
Hotter stars emit which color light?
Blue
300
How did scientists think the Moon formed?
A planet-sized object hit Earth.
300
This term describes the point in the Moon's orbit when it is farthest from the Earth.
Apogee
300
What causes day and night on Earth?
It revolving on it's axis.
300
The process that powers stars by combining hydrogen into helium is called this.
Nuclear Fusion
400
Astronomers estimate the average galaxy contains about this many stars.
100 billion
400
This is the galaxy closest to the Milky Way.
Andromeda Galaxy
400
What is the fine layer of dust covering the Moon’s surface called?
Regolith
400
This orbital shape causes the Moon to sometimes be closer to Earth and sometimes farther away.
Elliptical orbit
400
This is Earth's journey around the Sun.
Revolution
400
What type of star is our Sun classified as?
Yellow dwarf
500
This is the study of the origin and development of the universe.
Cosmology
500
According to the diagram, this wave carries more energy. 
High frequency
500
The Moon is not locked in place. Instead, it spins at the same rate that it orbits Earth, a phenomenon known as this.
Synchronous rotation
500
A full moon occurring near perigee is commonly known by this name.
Supermoon
500
This type of light occurs when the Sun's rays hit Earth at a shallow angle. This happens in areas that are tilted away from the Sun.
Indirect light
500
A star remains in equilibrium because these two opposing forces are balanced.
Gravity and gas pressure
600
I hold billions of stars in my embrace,
Yet I am only one place in space.
Spirals and ellipses are often my form,
What am I, where stars are born?
Galaxy
600
I'm measured crest to crest with care,
Long or short, I'm always there.
I help determine energy's might,
What am I describing in light?
Wavelength
600
Though meteors struck me by the score,
My scars remain forevermore.
No wind or rain to wear them down,
What are these circles all around?
Craters
600
Each night I grow a little more,
Until a bright full face I show.
What word describes my growing light?
Waxing
600
Twice a year I bring balance to all,
Equal day and night for large and small.
What am I?
Equinox
600
Not quite a star but getting hot,
Gathering mass is what I've got.
What stage am I?
Protostar