31.3 / 31.4 Flashcards
a large group of stars, dust, and gas held together by gravity
galaxy
a solar system including the Sun
Milky Way
contains fifty galaxies spread out over 10 million light years across. it includes the Milky Way
Local Group
the study of how the universe began, and what it is made of
cosmology
explanation for how the universe formed that states that all matter and energy in the universe were compressed into a single point, which began to expand outward about 13.7 billion years ago.
big bang theory
the residual microwave radiation emitted when the universe was very young
cosmic background radiation
an invisible form of matter that does not emit any detectable electromagnet energy of its own
dark matter
an invisible type of energy that creates a repulsive force causing the universe to expand at a faster rate
dark energy
What are the three shapes a galaxy can be?
spiral, elliptical, and irregular
Which galaxy are planets located in?
Milky Way
What shape is the Milky Way?
spiral
How many galaxies are in the local group?
50
What are the two largest galaxies in the local group?
Milky Way and Androneda
Where are we at in the Milky Way galaxy?
in the center
How long ago did the big bang occur?
13.7 billion years ago
