Chapter 21 Earth & Space Science

What is the approximate length of the cycle of the phases of the Moon?

29 ½ days

What major change did Copernicus make in the Ptolemaic system? Why was this change philosophically different?

Copernicus constructed a heliocentric model for the solar system. Everyone else believed in a geocentric solar system.

Newton discovered that the orbits of the planets are the result of opposing forces. Briefly explain these forces.

Each and every item in the solar system has a gravitational pull of some sort. The larger an item the greater the pull and the farther away an item the less the gravitational pull it has. Therefore if a larger planet is farther away, then it would have the same pull as a smaller planet closer together.

The first successful attempt to establish the size of Earth is credited to

Eratosthenes

The scientist that wrote a book that compared the Earth-centered system with the Sun-centered system entitled Dialogue of the Great World Systems

Galileo

Explain why Galileo's discovery of a rotating sun supports the Copernican view of a Sun-centered universe.

Galileo saw moons revolving around Jupiter so they couldn't be revolving around the Earth.

The true shape of the planetary orbits was discovered by

Johannes Kepler

Who discovered that planetary orbits were ellipses rather than circles?

Johannes Kepler

Explain the difference between the mean solar day and the sidereal day.

Mean solar day - The time interval from one noon to the next. 24 hrs. Sidereal day - Time it takes Earth to make one complete rotation with respect to a star other than our sun. 23 hrs. 56 min. 4 s.

Who wrote the book entitled Of the Revolutions of Celestial Spheres (De Revolutionibus)?

Nicolaus Copernicus

What phase of the Moon occurs approximately one week after the New Moon? Two weeks?

One week - First Quarter Two weeks - Full Moon

Does the Earth move faster in its orbit near perihelion (January) or near aphelion (July)?

Perihelion (January) - Days are shorter in Winter

The Earth-centered system of the universe that was accepted for nearly seventeen centuries was presented in a treatise called the Almagest that was written by

Ptolemy

Describe the three main primary motions of Earth.

Rotation - Turning or spinning, of a body on its axis. Revolution - Motion of a body such as a planet or a moon. Axial Precession - Gradual change in the orientation of Earth's axis over a period of 26,000 yrs.

The _____ day is the time it takes for the Earth to make one complete rotation with respect to a star other than the Sun

Sidereal

Who formulated the Law of Universal Gravitation

Sir Isaac Newton

What is different about the crescent phase that precedes the new-Moon phase and that which follows the new-Moon phase?

The crescent phase that precedes the new-Moon is the Waning or lit up on the left side. The crescent phase that follows the new-Moon is the Waxing or lit up on the right side.

What phenomenon results from the fact that the Moon's period of rotation and revolution are the same?

The same lunar hemisphere always faces Earth.

The Moon rotates very slowly (once in 27 ⅓ days) on its axis. How does this affect the lunar temperature surface?

The surface temperature in the daytime is 127C (261F) and during its nighttime -173C (280F)

What data did Tycho Brahe collect that was useful to Johannes Kepler in his quest to describe planetary motion.

Tycho Brahe collected data that is the stellar parallax. It is used to measure distances to the nearest stars.

A very slow motion of Earth's axis that requires 26,000 years to complete is

axial precession

In the Ptolemaic (Greek) model of the universe, the stars are attached to the

celestial sphere

The apparent path of the Sun upon the celestial sphere is called the

ecliptic

Any variance in the orbit of a planet from it predicted path is referred to as

perturbation

The apparent westward "drift" of the planets compared to the background stars is called

retrograde motion

The apparent westward drift of the planets as compared to the background of stars is called

retrograde motion

The period of time required for the Moon to complete one cycle of phases is called the ______ month

synodic

The length of daylight on the Moon is about

two weeks

The belt of constellations through which all the planets move is called

zodiac