Astronomy 101 - Final Exam Review
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Explain the physical reason why we on Earth experience day and night. - =Earth rotates about
an axis of rotation once every 24 hours.
What is a light year? - =The distance light travels in one year.
Approximately how far is the Sun from Earth? - =1 AU, 150 million km, 93 million miles, 8 light
minutes
About how far is the closest star to the Sun? - =4 light years
Explain why Earth has seasons. - =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. - =West to East
What two main factors dictate how bright a star is as seen from Earth? - =How intrinsically
bright it is and how far away it is.
What are commonly recognized star patterns known as? - =Constellations
What is significant about the Zodiac in the sky? - =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. - =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. -
=Gamma, x-ray, ultra violet, visible, infra red, microwave, radiowave
What is the light carrying particle known as? - =Photon
A fundamental limitation of a telescope's ability to resolve images, based on the wave-like
nature of light is known as _____. - =Diffraction
What can be determined by the peak of a blackbody spectrum? - =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? - =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? - =Photons are absorbed by atoms raising electrons
in atoms to higher energies
How is an emission spectrum spectrum generated? - =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? -
=All elements have their own unique absorption/emission spectra
What types of telescopes can be used on Earth? Why? - =Radio and optical/visible. Earth's
atmosphere is transparent at those wavelengths.
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Explain the physical reason why we on Earth experience day and night. - =Earth rotates about
an axis of rotation once every 24 hours.
What is a light year? - =The distance light travels in one year.
Approximately how far is the Sun from Earth? - =1 AU, 150 million km, 93 million miles, 8 light
minutes
About how far is the closest star to the Sun? - =4 light years
Explain why Earth has seasons. - =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. - =West to East
What two main factors dictate how bright a star is as seen from Earth? - =How intrinsically
bright it is and how far away it is.
What are commonly recognized star patterns known as? - =Constellations
What is significant about the Zodiac in the sky? - =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. - =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. -
=Gamma, x-ray, ultra violet, visible, infra red, microwave, radiowave
What is the light carrying particle known as? - =Photon
A fundamental limitation of a telescope's ability to resolve images, based on the wave-like
nature of light is known as _____. - =Diffraction
What can be determined by the peak of a blackbody spectrum? - =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? - =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? - =Photons are absorbed by atoms raising electrons
in atoms to higher energies
How is an emission spectrum spectrum generated? - =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? -
=All elements have their own unique absorption/emission spectra
What types of telescopes can be used on Earth? Why? - =Radio and optical/visible. Earth's
atmosphere is transparent at those wavelengths.
