unit 4 review

Question 1

what is the name of the most widely accepted theory of how the universe formed?

Answer 1

The Big Bang Theory

Question 2

how long ago do astronomers believe the universe formed?

Answer 2

approximately 13.7 billion years ago

Question 3

what was edwin hubble’s explanation when he noticed the light from distant galaxies was shifted toward the red part of the spectrum?

Answer 3

he suggested that galaxies were moving away from us

Question 4

how are galaxies and global clusters similar?

Answer 4

both contain large numbers of stars

Question 5

how are galaxies and global clusters different?

Answer 5

global clusters tend to be spherically shaped

Question 6

what nuclear process creates energy in stars?

Answer 6

fusion creates energy in stars

Question 7

which type of star, in terms of mass, becomes a red giant in its life cycle?

Answer 7

intermediate mass stars

Question 8

what is the name of the yellow surface of the sun?

Answer 8

photosphere

Question 9

why do sunspots appear darker than the areas surrounding them?

Answer 9

sunspots appear darker because they are cooler than the surrounding area

Question 10

what is the true shape of the planets’ orbits?

Answer 10

planets orbit in ellipses

Question 11

why do scientists not use the astronomical units to measure the distance to stars?

Answer 11

distances to stars are too great to use astronomical units