31.3 and 31.4 vocab

Question 1

galaxy

Answer 1

large group of stars, dust, and gas; held together by gravity

Question 2

Milky Way

Answer 2

spiral galaxy that is about 100,000 light-years in diameter and contains from 200 to 400 billion stars including the sun

Question 3

Local Group

Answer 3

group of about 50 galaxies including the Milky Way

Question 4

cosmology

Answer 4

study of how the universe began, what it is made of, and how it continues to evolve

Question 5

big bang theory

Answer 5

theory that about 13.7 billion years ago the entire universe was contained in a single point that began expanding outward

Question 6

cosmic background radiation

Answer 6

residual radiation from the formation of the universe; predicted by the big bang theory and later detected in 1965

Question 7

dark matter

Answer 7

type of matter that cannot be seen and can only be detected by its gravitational effects

Question 8

dark energy

Answer 8

energy that might be causing the accelerating expansion of the universe

Question 9

what shapes can a galaxy be

Answer 9

spiral, elliptical, and irregular

Question 10

what is the name of the galaxy we are located in

Answer 10

The Milky Way Galaxy

Question 11

what shape is the milky way galaxy

Answer 11

spiral

Question 12

how many galaxies make up our local group

Answer 12

about 50

Question 13

what are the two largest galaxies in our local group

Answer 13

the Andromeda and Milky Way galaxies

Question 14

where is our solar system located at in the milky way

Answer 14

in the center of one of the arms

Question 15

how long ago could the big bang have occurred

Answer 15

13.7 billion years ago

Question 16

what is the name of the effect that shows the changes in light waves

Answer 16

Doppler effect

Question 17

what is the universe made of

Answer 17

regular matter and dark matter

Question 18

question

Answer 18

answer