Earth Science Chapter 21
At the beginning of spring, the vernal equinox, what is the right ascension of the Sun?
0
At first quarter it is approximately ________ week(s) until the new Moon
3
If you determine the number of days in a year with solar time and sidereal time how would they vary?
A year measured in sidereal time would be about one day longer than a year based on solar time.
Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern. A) Kepler B) Galileo C) Newton D) Aristotle
Aristotle
think about the correlation of the celestial coordinate system, the tilt of Earth's axis, and the positions on Earth. If you are an observer in the Southern Hemisphere, 2 degrees north of the Tropic of Capricorn, What time of year will you be able to see the North Star?
Bon the Southern Hemisphere summer solstice, around Dec. 21
________ accurately recorded the position of the planet Mars.
Brahe
The first modern astronomer to propose a Sun-centered universe was ________.
Copernicus
The ancient Greeks proposed an ________-centered view of the universe.
Earth
In the Ptolemaic (Greek) model of the universe, ________.
Earth was in the center of the universe
The first scientist to use a telescope for astronomical purposes was ________.
Galileo
This scientist was the first to use the telescope in astronomy.
Galileo
This scientist wrote a book entitled Dialogue of the Great World Systems that compared the Earth-centered system with the Sun-centered system.
Galileo
________ discovered Jupiter's four largest moons.
Galileo
________ was convicted of heresy for his views of the universe.
Galileo
Tycho Brahe set out to disprove Copernicus, so why is he famous for developing modern astronomical theory?
He made very precise measurements that were key data used by Kepler.
Galileo believed in a ________ view of the universe.
Heliocentric
Why did Galileo's observation that Venus showed phases like the Moon indicate that the geocentric theory of the solar system was not possible?
It demonstrated that Venus could not be in orbit around Earth between Earth and the Sun because it shows "full" and "new" phases that would never occur with geocentric geometry.
Earth is closest to the Sun in ________.
January
The true shape of the planetary orbits was discovered by ________.
Johannes Kepler
Three laws of planetary motion were discovered by ________.
Johannes Kepler
Which astronomer developed the three laws of planetary motion?
Kepler
________ discovered the three laws of planetary motion.
Kepler
Alpha Centauri is a famous star because it is one of the closest stars to earth (other than the Sun of course). Where would you look in the night sky for Alpha Centauri?
Look for the brightest star in the constellation Centaurus
Using the telescope, Galileo discovered that the planet ________ had polar ice caps not unlike those on Earth.
Mars
The law of universal gravitation was formulated by ________.
Newton
The first modern astronomer to propose a Sun-centered universe was ________.
Nicolaus Copernicus
Who wrote the book entitled Of the Revolutions of Celestial Spheres (De Revolutionibus)?
Nicolaus Copernicus
Axial precession is sometimes called the precession of equinoxes because it results in a gradual shift, relative to the celestial background, of the position where the Sun crosses the celestial equator at the equinox. Astrology is a mythology based on things like your "sign" which refers to the position of the Sun in the celestial zodiac (the 12 constellations along the ecliptic) on your birthday. This system was established almost two thousand years ago. If this mythology were true (and you believe your horoscope) can you use the dates for your "sign" based on this 2000 year old system?
No, because 2000 years is almost 1/12, or one full sign shift, in the zodiac, so the 2000 year old signs are off by almost one full sign.
The Big Dipper is near the ________ celestial pole
North
What is the right ascension and declination for Polaris, the North Star?
RA indeterminate, D 90 degrees
Where will the North Star be, relative to the celestial coordinates, 12,000 years from now?
Several degrees from the North Pole position, and Vega will be the North Star instead of Polaris.
This scientist determined the nature of the forces that kept the planets in their orbits.
Sir Isaac Newton
Which of these men formulated the Law of Universal Gravitation?
Sir Isaac Newton
The concept that Earth was a sphere was established around the time of ________.
The Ancient Greeks
Why are there only 4-7 eclipses per year?
The Moon's orbit is inclined to the ecliptic and only crosses the ecliptic twice per year.
The concept that Earth maintained a circular orbit around the Sun was suggested during the time of ________.
The Renaissance
Earth hits its perihelion position in January. Solar radiation is proportional to the distance squared between the Sun and the earth, so why isn't it hot in "winter" at perihelion?
The ellipticity of the orbit is small, so the affect is small; seasons are caused by tilt of Earth's orbit.
The planets are "wanderers" in the night sky because they move relative to the stars. However, there movement is limited to the plane of the solar system, which is disk shaped. So relative to the celestial coordinate system, how do the planets actually move across the sky?
The move along the zodiac
Why do the planets "drift" east relative to the stars and then move west for periods of time?
They are moving in the same rotation sense as the earth around the Sun, but as the earth moves faster (or slower, depending on the planet) the motion appears to be backwards.
What is the modern explanation for what the ancient Chinese called "guest stars"?
They are nova or supernova.
How did Eratosthenes estimate the size of Earth?
They measured the angle of the Sun above the horizon at midday in two places with different latitude and used the angle to estimate the circumference of Earth.
Why were planets called "wanderers" by early astronomers?
They move relative to the stars.
A statement you will sometimes hear people say is that a day is not 24 hours but is really 23 hr. 56 min. and 4 sec. What does this refer to?
This is sidereal time, not solar time; a solar day is 24 hours.
Astrology is the folklore that arose from watching alignments in the night sky and the belief that these "celestial events" controlled human events. A 1960's folk song, "The Age of Aquarius" has numerous astrology references that relate to the positions of objects in the sky. The song has a line: "When the Moon is in the 7th house, and Jupiter aligns with Mars, then peace will guide the planet ..." From your knowledge of the stellar constellations and the celestial coordinate system, what does this line mean?
When Jupiter and Mars align in the sky, and the Moon is in the 7th constellation of the zodiac, then peace...
The Southern Cross is a Southern Hemisphere constellation that is as famous the big dipper in the Northern Hemisphere because of the brightness of the stars. It has a Southern Hemisphere declination slightly higher than the big dipper's Northern Hemisphere declination. Is it visible anywhere in the United States?
Yes, it is visible in Hawaii during the summer months.
The belt of constellations through which all the planets move is called the ________.
Zodiac
When Earth is the farthest from the Sun, it is said to be in the ________ position.
aphelion
The average distance from Earth to the Sun is called the ________ unit.
astronomical
A very slow motion of Earth's axis that requires 26,000 years to complete is called ________.
axial precession
In the Ptolemaic (Greek) model of the universe, the stars are attached to the ________.
celestial sphere
According to the Ptolemaic (Greek) system, the planets have ________ orbits
circular
Patterns or configurations of stars named in honor of mythological characters are called ________.
constellations
Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern. A) rotation B) precession C) revolution D) declination
declination
The angular distance north or south of the celestial equator is called ________.
declination
The earliest astronomical records appear to have been made by the ancient Chinese, Egyptians, and Babylonians in order to ________.
determine when to plant crops or hunt animals based on seasonal changes
Planets appear to move ________ each night, but occasionally they appear to stop and reverse direction.
eastward
The apparent annual path of the Sun upon the celestial sphere is called the ________.
ecliptic
The apparent path of the Sun upon the celestial sphere is called the ________.
ecliptic
The signs of the zodiac used in astrology refer to the constellations that lie along the plane of the ________.
ecliptic
One of the discoveries which led to the modern view of the solar system was that the orbits of the planets are ________.
ellipses
One of the discoveries that led to the modern view of the solar system was that the orbits of the planets are not circular but ________.
elliptical
When the Sun crosses the celestial equator, and day and night are of equal length around the globe, it is the time of the ________.
equinox
The proposal that contends that Earth is in the center of the universe is called the ________ view.
geocentric
The planets stay in orbit around the Sun because of a balance between gravity and ________.
inertia
When viewing the planets, Mars appears to move backwards, or retrograde, because ________.
it is rotating around the Sun slower than Earth's rotation
Solar eclipses are ________ lunar eclipses.
less common than
Lunar eclipses last ________ than solar eclipses.
longer
The cycle of phases of the Moon is the basis for our ________.
month
When the Moon appears as a thin crescent in the evening sky, just after Sunset, the lunar phase is ________.
new Moon
A total eclipse of the Sun is only possible at ________.
new moon
Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern. A) equatorial system B) perihelion C) right ascension D) declination
perihelion
When Earth is closest to the Sun, its location is referred to as the ________ position.
perihelion
Any variance in the orbit of a planet from its predicted path is referred to as ________.
perturbation
Kepler said that the ________ go(es) around the ________ on ________ orbits.
planets; Sun; elliptical
A very slow motion of Earth's axis that requires 26,000 years to complete is called ________.
precession
The apparent westward drift of the planets as compared to the background stars is called ________ motion.
retrograde
The apparent westward "drift" of the planets compared to the background stars is called ________.
retrograde motion
The two primary motions of Earth are ________ and ________.
rotation; revolution
The ________ side of the Moon is always visible from Earth.
same
According to the Ptolemaic (Greek) model of the universe, how many "heavenly" bodies could be observed wandering along the background of stars?
seven
The ________ day is the time it takes for Earth to make one complete rotation with respect to a star other than our Sun.
sidereal
What is the modern explanation for "guest stars" that appear in the night sky and then disappear?
stars that go nova or supernova and appear as bright objects during the event and then go away
The apparent shift in the position of a nearby star when viewed from extreme points in Earth's orbit six months apart is called ________.
stellar parallax
The 5000 year old Stonehenge stone circle of Salisbury Plains, England, allows light shafts to come straight between two rocks on ________ in the Northern hemisphere.
summer solstice
Galileo discovered that the Sun has "blemishes," which we call ________.
sunspots
The period of time required for the Moon to complete a cycle of phases is called the ________ month.
synodic
The Bayeux Tapestry is pictured here: Which astronomical event is featured in this picture?
the arrival of Haley's Comet
During a total lunar eclipse, the Moon remains visible because ________.
the atmosphere of the Earth refracts light around its perimeter
An eclipse of the Moon can be seen by anyone on ________.
the side of Earth facing the Moon at that time
A sidereal day is defined as ________.
the time for one complete revolution of the earth relative to the celestial reference
Galileo observed several features using the telescope. Which one of the following did he not discover?
the two moons of Mars
The length of daylight on the Moon is about ________.
two weeks
Relative to the celestial background, the Moon moves ________.
west to east
The belt of constellations through which all the planets move is called the ________.
zodiac