ASTRO 1 FINAL EXAM PSU EXAM WITH
CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS
LATEST ALREADY GRADED A+ 2025 – 2026
when do we think inflation happened? - ANSWERS-before
the big bang
what did universe look like at very beginning? - ANSWERS-
dense and hot
what evidence is there for the big bang? - ANSWERS-1.)
Cosmic Microwave Background
2.) Abundance of elements
3.) expansion of the universe
What is the CMB? - ANSWERS-thermal radiation left over
from the big bang
,Current temperature of the universe? - ANSWERS-2.73K
What did WMAP measure? - ANSWERS-temperature of the
universe
What is the fastest speed in the universe? - ANSWERS-speed
of light
Typical composition of stars - ANSWERS-74% H, 25% He, 1%
Metals
How old is the Sun/solar system? How much longer will it
live? - ANSWERS-4.5 billion, live to 10 billion
What is a star? - ANSWERS-glowing ball of hot dense gas
that generates its own energy via nuclear fusion
What is the reason that we have seasons on Earth? -
ANSWERS-tilt of the earth's axis determines what
hemisphere leans towards the sun
, If Earth's orbit were a perfect circle, how would this affect
seasons? - ANSWERS-Would not because earth's orbit is
already very close to a perfect circle
moon phases in order - ANSWERS-new moon, waxing
crescent, first quarter moon, waxing gibbous, full moon,
waning gibbous, third quarter moon, waning crescent
How long does it take to complete all the phases? -
ANSWERS-29.5 days
What are the two types of eclipses (only solar and lunar)
and what phase does the Moon need
to be in for each one of the eclipses to occur? - ANSWERS-
lunar: earth blocks sunlight from moon, full moon
solar: moon passing directly in front of sun, new moon
If you see that the Moon is full, what phase will someone in
Australia see? What about
someone on the Moon looking at Earth? - ANSWERS-the
same phase, the moon will just look upside down
people on the moon wouldn't see earth (new earth)
CORRECT ACTUAL QUESTIONS AND
CORRECTLY WELL DEFINED ANSWERS
LATEST ALREADY GRADED A+ 2025 – 2026
when do we think inflation happened? - ANSWERS-before
the big bang
what did universe look like at very beginning? - ANSWERS-
dense and hot
what evidence is there for the big bang? - ANSWERS-1.)
Cosmic Microwave Background
2.) Abundance of elements
3.) expansion of the universe
What is the CMB? - ANSWERS-thermal radiation left over
from the big bang
,Current temperature of the universe? - ANSWERS-2.73K
What did WMAP measure? - ANSWERS-temperature of the
universe
What is the fastest speed in the universe? - ANSWERS-speed
of light
Typical composition of stars - ANSWERS-74% H, 25% He, 1%
Metals
How old is the Sun/solar system? How much longer will it
live? - ANSWERS-4.5 billion, live to 10 billion
What is a star? - ANSWERS-glowing ball of hot dense gas
that generates its own energy via nuclear fusion
What is the reason that we have seasons on Earth? -
ANSWERS-tilt of the earth's axis determines what
hemisphere leans towards the sun
, If Earth's orbit were a perfect circle, how would this affect
seasons? - ANSWERS-Would not because earth's orbit is
already very close to a perfect circle
moon phases in order - ANSWERS-new moon, waxing
crescent, first quarter moon, waxing gibbous, full moon,
waning gibbous, third quarter moon, waning crescent
How long does it take to complete all the phases? -
ANSWERS-29.5 days
What are the two types of eclipses (only solar and lunar)
and what phase does the Moon need
to be in for each one of the eclipses to occur? - ANSWERS-
lunar: earth blocks sunlight from moon, full moon
solar: moon passing directly in front of sun, new moon
If you see that the Moon is full, what phase will someone in
Australia see? What about
someone on the Moon looking at Earth? - ANSWERS-the
same phase, the moon will just look upside down
people on the moon wouldn't see earth (new earth)