Transcript 9.3 UNSOLVED MYSTERIES HOMEWORK: PAGE 381 # 1, 5, 7, 8 KEY CONCEPTS: • The motions of stars and galaxies within clusters indicate that there.

9.3 UNSOLVED
MYSTERIES
HOMEWORK: PAGE 381 # 1, 5, 7, 8
KEY CONCEPTS:
• The motions of stars and galaxies within clusters
indicate that there are huge amounts of unseen
matter, called dark matter, around each galaxy.
• Dark matter makes up about 23% of the universenearly 6 times more than visible matter.
• Dark energy makes up about 73 % of the universe.
Astronomers believe that dark energy is responsible
for the increased expansion of the universe
DARK MATTER AND DARK ENERGY
Dark Matter: An undetected form of mass that emits
little or no photons, but we know it must exist
because we observe the effects of its gravity
Dark Energy: An unknown form of energy that is
causing the universe to expand faster over time
WHAT IS THE UNIVERSE MADE OF?
• Normal” Matter:
~ 4%
• Normal Matter inside stars: ~ 0.6%
• Normal Matter outside stars:
~ 3.4%
• Dark Matter:
• Dark Energy
~ 23%
~ 73%