Lesson Five
Galaxies are held together by ________.
gravity
A(n) ______ appears to emit regular bursts of radio waves.
pulsar
According to the bing bang theory, the universe formed about 13.7 ______ years ago.
billion
______ ______ is a spinning pulsar
Neutron star
What cold, creamy treat was first introduced at the St. Louis World’s Fair in 1904?
Ice cream
New stars tend to form in the ______ of a spiral galaxy.
arms
A(n) ________ is a large cloud of gas ad dust in space.
nebula
Radiation leftover from the big bang is called _________ __________ ___________.
cosmic background radiation
_____________ have mostly old stars, without a lot of active star formation.
Elliptical galaxies
Between what dates can the summer solstice fall?
June 20 and 22
_______ galaxies are small with many bright young stars and lots of gas and dust for star formation.
Irregular
A low - or medium - mass star becomes a(n) _________ at the end of its life.
white dwarf
___________ does not give off electromagnetic radiation.
Dark matter
_______ determines the life cycle of a star.
When is National Peach Month?
August
Astronomers can often identify binary systems that includes only one visible star by observing the effects of the dim star's __________ on its brighter companion.
gravity
An explosion that occurs at the end of a massive star's life is a(n) _________.
supernova
Hubble's law states that the farther away from us that a galaxy is, the _______ it is moving away from us.
faster
expand
Where is the “Barbeque Capital of the World”?
Kansas City, MO
A(n) _________ is a galaxy shaped like a flattened ball.
elliptical galaxy
Since no electromagnetic radiation escapes from a(n) ________ _______, astronomers locate them by looking for x-rays from gas accelerating toward them
black hole
According to the _______ _______ theory, the universe formed in a huge explosion.
big bang
___________ is causing the expansion of the universe to accelerate.
Dark energy
Which U.S. state was the first to make the Fourth of July an official holiday?
Massachusetts in 1870