section 2 and 3 of chapter 30 Flashcards
Galaxy
a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction
Milky Way,
The Milky Way is the galaxy that contains our Solar System, with the name describing the galaxy’s appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye
Local Group
Local Group, in astronomy, the group of more than 20 galaxies to which the Milky Way Galaxy belongs
Cosmology,
the science of the origin and development of the universe. Modern astronomy is dominated by the Big Bang theory, which brings together observational astronomy and particle physics
Big Bang Theory
The Big Bang theory is the prevailing cosmological model of the observable universe from the earliest known periods through its subsequent large-scale evolution
Cosmic Background Radiation
The cosmic microwave background, in Big Bang cosmology, is electromagnetic radiation which is a remnant from an early stage of the universe, also known as “relic radiation”.
Dark Matter
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–energy density or about 2.241×10−27 kg/m3
Dark Energy
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
what three shapes can a galaxy be
spiral and irregular
elliptical
which galaxy is our solar system located in
Milky way
where are we located in the milky way
in the center arm
how long ago did the big bang accrue
13.7 billion years ago
what is the name of the effect that shows change in life wave length
Doppler Effect
what is the universe made of
regular matter, dark matter
