Astronomy Test 1
based on observations of the universal expansion, the age of the universe is
14 billion years
Which of the following correctly lists out Cosmic address from small to large?
Earth, solar system, Milky Way galaxy, local group, local supercluster, universe
could we see a galaxy that is 20 billion light-years away
No because it would be beyond the bounds of the observable universe
how long does it take for light to travel from the Sun to the Earth
about 8 minutes
A typical galaxy is a
collection of a few hundred million to a trillion or more stars, bound together by gravity
A tv ad claiming that a product is light-years ahead of its time does not make sense because
it uses light-years to talk about time, but a light-year is a unit of distance
our solar system consists of
the Sun and all the objects that orbit it
When we say that the universe is expanding, we mean that
the average distance between galaxies is growing with time
what do astronomers mean by the big bang
the event that marked the beginning of the expansion of the universe
The total number of stars in the observable universe is roughly equal to
the number of grans of sand on all the beaches on Earth
Which of the following best describes what we mean by the universe?
the sum of all matter and energy
The fact that nearly all galaxies are moving away from us, with the more distant ones moving faster, tells us that
the universe is expanding
The star Betelgeuse is 425 light-years away. If it explodes tonight,
we wont know about it until 425 years from now
if stars existed but galaxies did not,
we would not exist because we are made of material that was recycled in the galaxies