Science vocab 31.3 - 31.4

Question 1

Galaxy

Answer 1

gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.

Question 2

Milky way

Answer 2

the galaxy that contains our Solar System, with the name describing the galaxy’s appearance from Earth

Question 3

Local Group

Answer 3

galaxy group that includes the Milky Way. It has a total diameter of roughly 3 megaparsecs

Question 4

cosmology

Answer 4

the science of the origin and development of the universe.

Question 5

big bang theory

Answer 5

The Big Bang theory is the prevailing cosmological model of the observable universe from the earliest known periods through its subsequent large-scale evolution

Question 6

cosmic background radiation

Answer 6

Cosmic background radiation is electromagnetic radiation from the Big Bang.

Question 7

dark matter

Answer 7

Dark matter is a form of matter thought to account for approximately 85% of the matter in the universe and about 27% of its total mass

Question 8

dark energy

Answer 8

Dark energy is the name given to the mysterious force that’s causing the rate of expansion of our universe to accelerate over time, rather than to slow down.