Astro 101 - Exam 1 UMich with 199
QUESTIONS AND ANSWERS
what is our planet in the solar system -
✅part of the solar system, in the milky way galaxy, in local group of galaxies, in local supercluster
how did we come to be -
✅the Big Bang which produced hydrogen and helium
where did elements come from -
✅the big bang produced H and He, which are the base of other elements constructed in stars
how old are we in comparison to the universe -
✅human civilization is a second of a year, and our own life is a fraction of a second
how is earth moving -
✅earth rotates on an axis once a day and orbits the Sun at 1 AU (150 million kilometers)
how can we specify the position of an object in the local sky -
✅altitude above the horizon and direction along the horizon
why do stars rise and set -
✅because of Earth's rotation
why do the constellations we see depend on latitude and time of year -
✅your location determines which constellations are hidden by earth
the time of year determines the location of the Sun and the celestial sphere
what causes the seasons -
✅the tilt of the Earth's axis
,what are the summer and winter solstices -
✅when the Northern hemisphere gets its most and least direction sunlight
what are the spring and fall equinoxes -
✅when both hemispheres get direct and equal sunlight
how does the orientation of Earth's axis change with time -
✅the tilt remains about 23.5 degrees (so the season pattern is not affected) but the the cycle
slowly and subtly changes the orientation of earth's axis every 26,000 years
why do we see phases of the moon -
✅half the Moon is lit by the Sun, half is in shadow, and its appearance to us is determined by the
relative positions of the Sun, Moon, and Earth
what causes eclipses -
✅-Lunar eclipse: Earth's shadow on the Moon
-Solar eclipse: Moon's shadow on Earth
-Tilt of Moon's orbit means eclipses occur during two periods each year
what was mysterious about the planetary motion in our sky -
✅like the sun and moon, planets usually drift eastward relative to the stars from night to night, but
sometimes, for a few weeks or few months, a planet turns westward in its apparent retrograde
motion
how did the Greeks explain planetary motion -
✅The Ptolemaic model had each planet move on a small circle whose center moves around Earth
on a larger circle
Copernicus -
✅created a Sun-centered model
Tycho -
✅provided the data needed to improve Copernicus' model
, Kepler -
✅found a model that fit Tycho's data
Kepler's 1st Law of Planetary Motion -
✅each planet orbits the sun in a path called an ellipse with the sun at one focus
Kepler's Second Law of Planetary Motion -
✅As a planet moves around its orbit it sweeps out equal areas in equal times.
a planet travels faster when it is nearer to the sun and slower when it is farther form the sun
Kepler's Third Law of Planetary Motion -
✅The square of the orbital period of any satellite is proportional to the cube of its average distance
from its central mass
More distant planets orbit the Sun at slower average speeds: p2 = a3 (p= orbital period in years and
a= average distance from Sun in AU)
Galileo -
✅his experiments and observations overcame the remaining objections to the Sun-centered solar
system model
what is a scientific theory -
✅A model that explains a wide variety of observations in terms of a few general principles and that
has survived repeated and varied testing
how is astrology different from astronomy -
✅- Astronomy is the scientific study of the universe
and the celestial objects within it
- Astrology assumes that the positions of celestial
objects influence human events
QUESTIONS AND ANSWERS
what is our planet in the solar system -
✅part of the solar system, in the milky way galaxy, in local group of galaxies, in local supercluster
how did we come to be -
✅the Big Bang which produced hydrogen and helium
where did elements come from -
✅the big bang produced H and He, which are the base of other elements constructed in stars
how old are we in comparison to the universe -
✅human civilization is a second of a year, and our own life is a fraction of a second
how is earth moving -
✅earth rotates on an axis once a day and orbits the Sun at 1 AU (150 million kilometers)
how can we specify the position of an object in the local sky -
✅altitude above the horizon and direction along the horizon
why do stars rise and set -
✅because of Earth's rotation
why do the constellations we see depend on latitude and time of year -
✅your location determines which constellations are hidden by earth
the time of year determines the location of the Sun and the celestial sphere
what causes the seasons -
✅the tilt of the Earth's axis
,what are the summer and winter solstices -
✅when the Northern hemisphere gets its most and least direction sunlight
what are the spring and fall equinoxes -
✅when both hemispheres get direct and equal sunlight
how does the orientation of Earth's axis change with time -
✅the tilt remains about 23.5 degrees (so the season pattern is not affected) but the the cycle
slowly and subtly changes the orientation of earth's axis every 26,000 years
why do we see phases of the moon -
✅half the Moon is lit by the Sun, half is in shadow, and its appearance to us is determined by the
relative positions of the Sun, Moon, and Earth
what causes eclipses -
✅-Lunar eclipse: Earth's shadow on the Moon
-Solar eclipse: Moon's shadow on Earth
-Tilt of Moon's orbit means eclipses occur during two periods each year
what was mysterious about the planetary motion in our sky -
✅like the sun and moon, planets usually drift eastward relative to the stars from night to night, but
sometimes, for a few weeks or few months, a planet turns westward in its apparent retrograde
motion
how did the Greeks explain planetary motion -
✅The Ptolemaic model had each planet move on a small circle whose center moves around Earth
on a larger circle
Copernicus -
✅created a Sun-centered model
Tycho -
✅provided the data needed to improve Copernicus' model
, Kepler -
✅found a model that fit Tycho's data
Kepler's 1st Law of Planetary Motion -
✅each planet orbits the sun in a path called an ellipse with the sun at one focus
Kepler's Second Law of Planetary Motion -
✅As a planet moves around its orbit it sweeps out equal areas in equal times.
a planet travels faster when it is nearer to the sun and slower when it is farther form the sun
Kepler's Third Law of Planetary Motion -
✅The square of the orbital period of any satellite is proportional to the cube of its average distance
from its central mass
More distant planets orbit the Sun at slower average speeds: p2 = a3 (p= orbital period in years and
a= average distance from Sun in AU)
Galileo -
✅his experiments and observations overcame the remaining objections to the Sun-centered solar
system model
what is a scientific theory -
✅A model that explains a wide variety of observations in terms of a few general principles and that
has survived repeated and varied testing
how is astrology different from astronomy -
✅- Astronomy is the scientific study of the universe
and the celestial objects within it
- Astrology assumes that the positions of celestial
objects influence human events
