Test Bank for The Essential Cosmic Perspective
ecliptic - Answers the path the Sun follows as it appears to circle around the celestial sphere
once each year. It crosses the celestial equator at a 23 1/2° angle, because that is the tilt of
Earth's axis.
triangulation - Answers a geometric method of measuring of the distance of a planet or nearby
star by sighting its apparent position against background stars from two or more separate
locations.
celestial sphere - Answers the illusion that the stars and constellations lie on the same plane, a
sphere around the earth- and are the same distance away; ancient Greeks mistook this illusion
for reality because they lacked the depth perception, since the stars were so far away; a useful
illusion, because it allows us to map the sky as seen from Earth.
solstices - Answers The summer solstice, occurring around June 21, is the moment when the
Northern Hemisphere is tilted most directly toward the Sun (23° above the celestial equator)
and the Southern Hemisphere is tipped most directly away from it. The winter solstice,
occurring around December 21, is the moment when the Northern Hemisphere is tilted most
directly away from the Sun (23° below the celestial equator) and the Southern Hemisphere is
tipped most directly toward it. The spring and fall equinoxes (March & September) are the two
times when both hemispheres get equally direct sunlight.
celestial coordinates - Answers a useful coordinate system for locating objects on the celestial
sphere by projecting onto the sky the latitude-longitude coordinate system that we use on the
surface of the earth; the coordinates of right ascension and declination that fix an object's
position on the celestial sphere.
locating an object in our local sky - Answers the boundary between Earth and sky defines the
horizon. The point directly overhead is the zenith. The meridian is an imaginary half- circle
stretching from the horizon due south, through the zenith, to the horizon due north; it divides
rising stars from setting stars) We can pinpoint the position of any object in the local sky by
,stating its direction along the horizon (sometimes stated as azimuth, which is degrees clockwise
from due north) and its altitude above the horizon. Note that the zenith has altitude 90° but no
direction, because it is straight overhead (i.e.: if the north celestial pole is 35° above your
northern horizon. This tells you that your latitude on the globe is 35° north of the equator).
How could you determine that the Earth is revolving around the sun? - Answers Parallax. Over
the course of one year many of the stars will move relative to each other. At the end of the year
they will be back where they started. This is because the Earth moves around in a 2AU diameter
circle, so that six months from your first observation, you'll be standing 2AU away from where
you were then, and are viewing the stars from a (slightly, but observably) different angle.
Polaris, the North Star, does not appear to move in the sky because - Answers it lies
approximately over the northern axis of the Earth.
How many arc seconds are in a degree? - Answers 3,600 seconds.
What contribution to astronomy did Tycho Brahe make? - Answers He made extensive and
detailed observations of the positions of the planets.
The moon is growing more full each night. This is called - Answers waxing.
The Ptolemaic picture of the universe probably survived for so long because - Answers it was
based on precise measurements of planetary positions.
When we see Saturn going through a period of apparent retrograde motion, it means - Answers
Earth is passing Saturn in its orbit, with both planets on the same side of the Sun.
The age of our solar system is about - Answers One-third the age of our Universe.
, I live in the United States, and during my first trip to Argentina
I saw many constellations that I'd never seen before. - Answers Yes, Argentina's southern
location affords us a different view of the night sky from what is visible in the United States.
astronomical unit - Answers or AU, equivalent to about 150 million kilometers (93 million miles);
the distance from the Earth to the Sun.
solar eclipse - Answers occurs when the moon passes directly between the sun and Earth and
casts a shadow over part of Earth.
aphelion - Answers the place in the orbit of a planet where it is farthest from the sun; the
closest being the perihelion.
autumnal equinox - Answers Occurs on or about September 22 when both hemispheres of the
Earth receive 12 hours of daylight and 12 hours of night.
retrograde motion - Answers The apparent motion of the planets when they appear to move
backwards (westward) with respect to the stars from the direction that they move ordinarily.
What is the zodiac, and why do we see different parts of it at different times of the year? -
Answers the 12 constellations we see in our local sky; the Earth is tilted 23 ½° on it axis as we
rotate around the sun, west to east, making the stars appear to rise in the east and set in the
west. We see different parts of the zodiac depending on where Earth is in its orbit.
What is the Copernican revolution? - Answers The combined research, observational data and
theories of Copernicus, Tycho Brahe, and Kepler, finalized by Galileo. Copernicus overturned the
Ptolemaic model (theory that each planet moves on a small circle whose center moves around
Earth on a larger circle) in favor of a sun-centered model. Brahe continued this work and
improved it (only slightly), using years of naked-eye observation. He hired Kepler, who
discovered through discrepancies in Brahe's data on planetary motion (Brahe could not detect
stellar parallax & thought planets orbited in perfect circles) that orbits are ellipses. This helped
him postulate his 3 laws of planetary motion. Galileo then cemented the sun-centered model
ecliptic - Answers the path the Sun follows as it appears to circle around the celestial sphere
once each year. It crosses the celestial equator at a 23 1/2° angle, because that is the tilt of
Earth's axis.
triangulation - Answers a geometric method of measuring of the distance of a planet or nearby
star by sighting its apparent position against background stars from two or more separate
locations.
celestial sphere - Answers the illusion that the stars and constellations lie on the same plane, a
sphere around the earth- and are the same distance away; ancient Greeks mistook this illusion
for reality because they lacked the depth perception, since the stars were so far away; a useful
illusion, because it allows us to map the sky as seen from Earth.
solstices - Answers The summer solstice, occurring around June 21, is the moment when the
Northern Hemisphere is tilted most directly toward the Sun (23° above the celestial equator)
and the Southern Hemisphere is tipped most directly away from it. The winter solstice,
occurring around December 21, is the moment when the Northern Hemisphere is tilted most
directly away from the Sun (23° below the celestial equator) and the Southern Hemisphere is
tipped most directly toward it. The spring and fall equinoxes (March & September) are the two
times when both hemispheres get equally direct sunlight.
celestial coordinates - Answers a useful coordinate system for locating objects on the celestial
sphere by projecting onto the sky the latitude-longitude coordinate system that we use on the
surface of the earth; the coordinates of right ascension and declination that fix an object's
position on the celestial sphere.
locating an object in our local sky - Answers the boundary between Earth and sky defines the
horizon. The point directly overhead is the zenith. The meridian is an imaginary half- circle
stretching from the horizon due south, through the zenith, to the horizon due north; it divides
rising stars from setting stars) We can pinpoint the position of any object in the local sky by
,stating its direction along the horizon (sometimes stated as azimuth, which is degrees clockwise
from due north) and its altitude above the horizon. Note that the zenith has altitude 90° but no
direction, because it is straight overhead (i.e.: if the north celestial pole is 35° above your
northern horizon. This tells you that your latitude on the globe is 35° north of the equator).
How could you determine that the Earth is revolving around the sun? - Answers Parallax. Over
the course of one year many of the stars will move relative to each other. At the end of the year
they will be back where they started. This is because the Earth moves around in a 2AU diameter
circle, so that six months from your first observation, you'll be standing 2AU away from where
you were then, and are viewing the stars from a (slightly, but observably) different angle.
Polaris, the North Star, does not appear to move in the sky because - Answers it lies
approximately over the northern axis of the Earth.
How many arc seconds are in a degree? - Answers 3,600 seconds.
What contribution to astronomy did Tycho Brahe make? - Answers He made extensive and
detailed observations of the positions of the planets.
The moon is growing more full each night. This is called - Answers waxing.
The Ptolemaic picture of the universe probably survived for so long because - Answers it was
based on precise measurements of planetary positions.
When we see Saturn going through a period of apparent retrograde motion, it means - Answers
Earth is passing Saturn in its orbit, with both planets on the same side of the Sun.
The age of our solar system is about - Answers One-third the age of our Universe.
, I live in the United States, and during my first trip to Argentina
I saw many constellations that I'd never seen before. - Answers Yes, Argentina's southern
location affords us a different view of the night sky from what is visible in the United States.
astronomical unit - Answers or AU, equivalent to about 150 million kilometers (93 million miles);
the distance from the Earth to the Sun.
solar eclipse - Answers occurs when the moon passes directly between the sun and Earth and
casts a shadow over part of Earth.
aphelion - Answers the place in the orbit of a planet where it is farthest from the sun; the
closest being the perihelion.
autumnal equinox - Answers Occurs on or about September 22 when both hemispheres of the
Earth receive 12 hours of daylight and 12 hours of night.
retrograde motion - Answers The apparent motion of the planets when they appear to move
backwards (westward) with respect to the stars from the direction that they move ordinarily.
What is the zodiac, and why do we see different parts of it at different times of the year? -
Answers the 12 constellations we see in our local sky; the Earth is tilted 23 ½° on it axis as we
rotate around the sun, west to east, making the stars appear to rise in the east and set in the
west. We see different parts of the zodiac depending on where Earth is in its orbit.
What is the Copernican revolution? - Answers The combined research, observational data and
theories of Copernicus, Tycho Brahe, and Kepler, finalized by Galileo. Copernicus overturned the
Ptolemaic model (theory that each planet moves on a small circle whose center moves around
Earth on a larger circle) in favor of a sun-centered model. Brahe continued this work and
improved it (only slightly), using years of naked-eye observation. He hired Kepler, who
discovered through discrepancies in Brahe's data on planetary motion (Brahe could not detect
stellar parallax & thought planets orbited in perfect circles) that orbits are ellipses. This helped
him postulate his 3 laws of planetary motion. Galileo then cemented the sun-centered model
