Astronomy 101 - Final Exam Review questions and
Verified Answers
Explain the physical reason why we on Earth experience day and night. - ANSWER Earth rotates
about an axis of rotation once every 24 hours.
What is a light year? - ANSWER The distance light travels in one year.
Approximately how far is the Sun from Earth? - ANSWER 1 AU, 150 million km, 93 million miles,
8 light minutes
About how far is the closest star to the Sun? - ANSWER 4 light years
Explain why Earth has seasons. - ANSWER Earth's axis is tilted with respect to the orbital plane.
When the northern hemisphere is tilted toward the Sun it is summer, even though we are
further from the Sun.
Objects in the sky rise in the east and set in the west because Earth rotates from ___ to ___
about its axis. - ANSWER West to East
What two main factors dictate how bright a star is as seen from Earth? - ANSWER How
intrinsically bright it is and how far away it is.
What are commonly recognized star patterns known as? - ANSWER Constellations
What is significant about the Zodiac in the sky? - ANSWER They lie along the plane of the
ecliptic (the plane of the solar system)
, Explain why stars appear at the same locations on the celestial sphere while the Sun, Moon,
and planets move during the course of the year. - ANSWER The stars are so incredibly far away
that even though they are moving, the motion is hardly recognizable from Earth .
List the 7 major types of electromagnetic radiation (light) from highest to lowest energy. -
ANSWER Gamma, x-ray, ultra violet, visible, infra red, microwave, radiowave
What is the light carrying particle known as? - ANSWER Photon
A fundamental limitation of a telescope's ability to resolve images, based on the wave-like
nature of light is known as _____. - ANSWER Diffraction
What can be determined by the peak of a blackbody spectrum? - ANSWER Peak indicates the
temperature of the object
How would the blackbody spectrum of stars that are the same temperature differ between a
large and small star? - ANSWER The peaks would be at the same location, since they are the
same temperature, but the peak would be higher for the larger star (more energy emitted per
second)
How is an absorption spectrum generated? - ANSWER Photons are absorbed by atoms raising
electrons in atoms to higher energies
How is an emission spectrum spectrum generated? - ANSWER Photons are emitted by atoms
lowering the energy of electrons in the atom
Do any elements on the periodic table have the exact same absorption/emission spectrum? -
ANSWER All elements have their own unique absorption/emission spectra
What types of telescopes can be used on Earth? Why? - ANSWER Radio and optical/visible.
Earth's atmosphere is transparent at those wavelengths.
Verified Answers
Explain the physical reason why we on Earth experience day and night. - ANSWER Earth rotates
about an axis of rotation once every 24 hours.
What is a light year? - ANSWER The distance light travels in one year.
Approximately how far is the Sun from Earth? - ANSWER 1 AU, 150 million km, 93 million miles,
8 light minutes
About how far is the closest star to the Sun? - ANSWER 4 light years
Explain why Earth has seasons. - ANSWER Earth's axis is tilted with respect to the orbital plane.
When the northern hemisphere is tilted toward the Sun it is summer, even though we are
further from the Sun.
Objects in the sky rise in the east and set in the west because Earth rotates from ___ to ___
about its axis. - ANSWER West to East
What two main factors dictate how bright a star is as seen from Earth? - ANSWER How
intrinsically bright it is and how far away it is.
What are commonly recognized star patterns known as? - ANSWER Constellations
What is significant about the Zodiac in the sky? - ANSWER They lie along the plane of the
ecliptic (the plane of the solar system)
, Explain why stars appear at the same locations on the celestial sphere while the Sun, Moon,
and planets move during the course of the year. - ANSWER The stars are so incredibly far away
that even though they are moving, the motion is hardly recognizable from Earth .
List the 7 major types of electromagnetic radiation (light) from highest to lowest energy. -
ANSWER Gamma, x-ray, ultra violet, visible, infra red, microwave, radiowave
What is the light carrying particle known as? - ANSWER Photon
A fundamental limitation of a telescope's ability to resolve images, based on the wave-like
nature of light is known as _____. - ANSWER Diffraction
What can be determined by the peak of a blackbody spectrum? - ANSWER Peak indicates the
temperature of the object
How would the blackbody spectrum of stars that are the same temperature differ between a
large and small star? - ANSWER The peaks would be at the same location, since they are the
same temperature, but the peak would be higher for the larger star (more energy emitted per
second)
How is an absorption spectrum generated? - ANSWER Photons are absorbed by atoms raising
electrons in atoms to higher energies
How is an emission spectrum spectrum generated? - ANSWER Photons are emitted by atoms
lowering the energy of electrons in the atom
Do any elements on the periodic table have the exact same absorption/emission spectrum? -
ANSWER All elements have their own unique absorption/emission spectra
What types of telescopes can be used on Earth? Why? - ANSWER Radio and optical/visible.
Earth's atmosphere is transparent at those wavelengths.
