Grossmont Astronomy 110 Final Exam
Study Guide
What are constellations? How many are there? - ANS-A group of stars.88
What is the celestial sphere? - ANS-An imaginary sphere that maps all celestial objects.
What is the celestial equator? - ANS-Earth's equator expanded onto the celestial
sphere.
What is an ecliptic? - ANS-A circle on the celestial sphere representing the sun's
apparent path during the year.
What are the North and South celestial poles? - ANS-Earth's north and south pole
expanded onto the celestial sphere.
What is the difference between the solar and sidereal day (in minutes)? - ANS-It rises 4
minutes earlier each successive night, and the length of daylight hours varies.
How long does it take the Earth to rotate (in hours)? - ANS-24.
How long does it take the Earth to revolve (in decimal days)? - ANS-365.25
How long does it take the Earth to precess (in years)? - ANS-26,000
What causes seasons? - ANS-Earth's rotation axis inclined by 23.5 degrees.
When are the Spring and Fall equinox? - ANS-Spring equinox is on March 20th and Fall
equinox is on September 22nd.
When is the Summer solstice? - ANS-Summer solstice has the most time of daylight
and is on June 21st.
When is the Winter solstice? - ANS-Winter Solstice has the least time of daylight and is
on December 21st.
How long is a lunar month? - ANS-29-30 days
, How long is the Moon's orbit and rotation period? - ANS-27 days.
Why do we see phases of the Moon? - ANS-The revolution of the moon around the
Earth allows us to see different amounts of the Moon being illuminated.
Why do we see the same face of the Moon? - ANS-The rotational period is exactly the
same as the orbital period.
What is a solar eclipse and how does it occur? - ANS-A solar eclipse occurs when the
moon gets between Earth and the Sun, and only occurs at the phase of new moon.
The three types of solar eclipses are partial, annular, and total.
What is a lunar eclipse and how does it occur? - ANS-A lunar eclipse occurs when the
moon passes directly behind the Earth, and can only occur on a full moon night.
The three types of lunar eclipses are partial, penumbral, and total.
What was Aristotle's idea for the universe? Why was he wrong? - ANS-He thought the
Earth was the center of the universe, but it's actually the Sun.
What was Ptolemy's idea for the geocentric model? - ANS-Epicycles, circles upon
circles.
How did Ptolemy try to explain retrograde motion? - ANS-With epicycles, he could
explain the complicated motion.
Why was Ptolemy wrong? - ANS-They move in ellipses, and the Sun is the center.
What was Eratosthenes' contribution to astronomy? - ANS-He measured Earths radius
about 2300 years ago.
What were Aristarchus' contributions to astronomy? - ANS-First astronomer to have
idea of heliocentric universe, and found distances to the Sun and the Moon.
What was Copernicus' idea for the Universe? - ANS-Planets moved around the Sun in
perfect circles.
How did Copernicus explain retrograde motion? Why was part of the Copernican idea
wrong? - ANS-He used a lot of epicycles to make accurate predictions for the motions,
and he was wrong because they moved in ellipses.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Hkane. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
