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