HW5

A  The moon closest to Daniel.

B  The smallest moon will orbit the fastest, just like Mercury (the smallest planet) orbits the Sun the fastest.

C  The moon farthest away from Daniel.

D  There’s no way to determine which moon rotates the fastest without knowing their relative masses.

A  If you lived on Mercury, you would notice that Earth exhibits retrograde motion for a while every year.

B  As seen from Earth’s surface, planets rise in the east and set in the west, even when they undergo retrograde motion.

C  Our observations of a full or gibbous Venus provide evidence against the Ptolemaic, Earth-centered model of the Solar System

D  Copernicus’ model of the Solar System was accepted shortly after being proposed, because it provided significantly more accurate positions of the planets than did the Ptolemaic system.

E  According to Kepler’s first law, the orbit of planets are ellipses with the Sun at one focus; there is no object at the second focus.

A  Craters and mountains on the Moon.

B  Jupiter’s four large moons.

C  Large numbers of stars in the Milky Way.

D  A given planet’s speed among the background stars varies with time.

E  The full set of phases of Venus.

A  the backward motion of a planet through the sky

B  the east to west motion of a planet compared to the viewer’s horizon

C  the west to east motion of a planet against the stars

D  the apparent backward motion of a planet against the fixed stars

A  distance from the Sun

B  radius

C  speed of revolution

D  mass

A  FALSE

B  TRUE

A  around the Sun in roughly the same plane

B  in ellipses in random directions

C  as far apart as possible

D  bound by gravity of the planets

A  It travels from east to west each night.

B  My life will be Topsy-turvy.

C  Each night, it makes a loop in the sky.

D  If I take a picture of it each week at roughly the same time, against the fixed stars, and connect the dots, it will appear to travel from west to east.

E  It travels from west to east each night.

A  Copernicus was wrong.

B  Both Venus & Mars had epicycles.

C  Venus revolved about the Sun.

D  Venus rotated about Earth.

A  FALSE

B  TRUE