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Umich Astro 101 test 1 Questions and
Correct Answers
Solar system Ans: consists of the sun planets, moons, and smaller
objects including asteroid(rocky) and comets(ice rocks)
Milky way galaxy Ans: disk-shaped collection of stars
Galaxy Ans: great island of stars containg between a few hundred
million to a trillion or more.
Local Group Ans: a local group of galaxies
Astronomical Unit (AU) Ans: average distance between the Earth
and the Sun
Light-year (Ly) Ans: distance that light can travel in one year. 10
tril kilometers
Nebula Ans: A large cloud of gas and dust in space, spread out in
an immense volume
Observable Universe Ans: the part of the universe that can be
observed, because light has had time to travel to earth
Cosmic Calender Ans: A scale on which we compress the history
of the universe into 1 year. We are currently in the last second of
the day
4 motions earth is experiencing Ans: 1st: Rotation- the earth is
rotating on its axis once a day. faster at the equator
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2nd: Orbit- Earth obits the sun once a year. Average distance of 1
AU and the axis is tilied by 23.5 degrees pointing towards Polaris.
3rd: The sun and the solar system move with the local solar
neighborhood
4th: everything moves with the rotation of the milky way
Hubble discovered that: Ans: The more distant the galaxy, the
faster it is racing away and all galaxies outside our local group are
moving away from us
Constellation Ans: is a region of the sky. there are 88 that make up
the sky
Celestial Sphere Ans: a useful tool for learning. it is the illusion of
stars all lying the same distance from earth.
North celestial pole Ans: point directly over earths north pole
south celestial pole Ans: point directly over Earth's South Pole
Celestial equator Ans: The extension of the Earth's equator out
onto the celestial sphere.
Ecliptic Ans: path of the sun and the planets that they appear to
circle around the celestial sphere. crosses equator at 23.5 dragrees
because of the tilt of the axis.
Local sky Ans: The sky as seen from wherever you happen to be
standing - appears to take shape of a hemisphere or a dome
Horizon Ans: boundary between earth and sky
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Zenith Ans: point directly overhead
meridian Ans: imaginary half circle stretching from the horizon
due south through the zenith to the horizon due north
Position of object in sky Ans: stating its DIRECTION along the
horizon and altitude above the horizon
angular size Ans: the angle an object appears to span in your field
of view.
physical size 360degrees/ 2pi distance
angular distance Ans: angle that appears to separate two objects
in sky
Angular measurements Ans: 1 degree is 60' arcminutes
1 arminute is 60'' arcseconds
circumpolar Ans: A term describing a star that neither rises nor
sets but appears to rotate around one of the celestial poles.
why do the constellations we see depend on latitude and time of
year? Ans: They depend on latitude because your position on Earth
determines which constellations remain below the horizon.
They depend on time of year because Earth's orbit changes the
apparent location of the Sun among the stars.
Latitude Ans: Distance north or south of the Equator, measured in
degrees.
© 2025 All rights reserved
Umich Astro 101 test 1 Questions and
Correct Answers
Solar system Ans: consists of the sun planets, moons, and smaller
objects including asteroid(rocky) and comets(ice rocks)
Milky way galaxy Ans: disk-shaped collection of stars
Galaxy Ans: great island of stars containg between a few hundred
million to a trillion or more.
Local Group Ans: a local group of galaxies
Astronomical Unit (AU) Ans: average distance between the Earth
and the Sun
Light-year (Ly) Ans: distance that light can travel in one year. 10
tril kilometers
Nebula Ans: A large cloud of gas and dust in space, spread out in
an immense volume
Observable Universe Ans: the part of the universe that can be
observed, because light has had time to travel to earth
Cosmic Calender Ans: A scale on which we compress the history
of the universe into 1 year. We are currently in the last second of
the day
4 motions earth is experiencing Ans: 1st: Rotation- the earth is
rotating on its axis once a day. faster at the equator
© 2025 All rights reserved
, 2 | Page
2nd: Orbit- Earth obits the sun once a year. Average distance of 1
AU and the axis is tilied by 23.5 degrees pointing towards Polaris.
3rd: The sun and the solar system move with the local solar
neighborhood
4th: everything moves with the rotation of the milky way
Hubble discovered that: Ans: The more distant the galaxy, the
faster it is racing away and all galaxies outside our local group are
moving away from us
Constellation Ans: is a region of the sky. there are 88 that make up
the sky
Celestial Sphere Ans: a useful tool for learning. it is the illusion of
stars all lying the same distance from earth.
North celestial pole Ans: point directly over earths north pole
south celestial pole Ans: point directly over Earth's South Pole
Celestial equator Ans: The extension of the Earth's equator out
onto the celestial sphere.
Ecliptic Ans: path of the sun and the planets that they appear to
circle around the celestial sphere. crosses equator at 23.5 dragrees
because of the tilt of the axis.
Local sky Ans: The sky as seen from wherever you happen to be
standing - appears to take shape of a hemisphere or a dome
Horizon Ans: boundary between earth and sky
© 2025 All rights reserved
, 3 | Page
Zenith Ans: point directly overhead
meridian Ans: imaginary half circle stretching from the horizon
due south through the zenith to the horizon due north
Position of object in sky Ans: stating its DIRECTION along the
horizon and altitude above the horizon
angular size Ans: the angle an object appears to span in your field
of view.
physical size 360degrees/ 2pi distance
angular distance Ans: angle that appears to separate two objects
in sky
Angular measurements Ans: 1 degree is 60' arcminutes
1 arminute is 60'' arcseconds
circumpolar Ans: A term describing a star that neither rises nor
sets but appears to rotate around one of the celestial poles.
why do the constellations we see depend on latitude and time of
year? Ans: They depend on latitude because your position on Earth
determines which constellations remain below the horizon.
They depend on time of year because Earth's orbit changes the
apparent location of the Sun among the stars.
Latitude Ans: Distance north or south of the Equator, measured in
degrees.
© 2025 All rights reserved
