Vocabulary
What is a comet?
A small object made of ice and dust that orbits the Sun.
What 2 things make up the universe?
Matter and Energy
Name 3 out of the 5 characterizations of stars.
Color, temperature, size, composition, brightness.
How are many constellations named?
After characters in Greek myths.
Name 2 of the 4 terrestrial planets.
Mercury, Venus, Earth, and Mars.
What is a star system?
A group of two or more stars.
What explosion created the universe?
The Big Bang
What are the 2 types of star clusters?
Open clusters: loose and disorganized.
Globular clusters: tightly packed groups of older stars.
For how long was the geocentric model believed?
For more than a millennium.
What types of gas make up gas giants?
Helium, water vapor, and hydrogen.
What is a light-year?
The distance that light travels in 1 year.
How are inner planets formed?
(Planets include Mercury, Venus, Earth, and Mars.)
These are called terrestrial planets.
How can you identify a spiral galaxy.
Has a bulge in the center, contains mostly old, red stars.
Has arms that curve in a spiral pattern, contains young blue and white stars.
Contains much gas and dust.
Who created the Geocentric Model?
Aristotle.
What is larger, terrestrial planets or gas giants?
Gas giants are much larger!
What is dark energy?
A type of energy that opposes gravity and causes the expansion of the universe.
What factors do scientists use to calculate the age of the universe? (Name 2 of the 3)
The patterns of background radiation.
How fast distant galaxies move away from us.
The age of the oldest stars.
What is special about an elliptical galaxy?
Has almost no dust and gas between stars.
Has no new stars being formed.
What is the main idea in the Heliocentric Model?
The Sun is the center of the universe.
Besides the planets, what 4 types of bodies make up the solar system? Name 3 of the 4.
Sun, Comets, Asteroids, and Meteroids.
What is geocentric?
A model of the solar system where the Sun and planets orbit around the Earth.
What is another name for the Outer Planets?
How are they formed?
They are also called gas giants.
They form farther away from the Sun, where temperatures are cooler.
What type of starts are found in irregular galaxies?
They contain many young stars.
What happens to the speed of planets when they are close to the Sun?
They move faster - discovered by Kepler.
What are the two ways we continue to learn about the solar system?
Lunar Explorations.
Space Probes (such as Juno, exploring Jupiter.)