Chapter 27 Vocab

Question 1

a planet that has a deep massive atmosphere, such as Jupiter, Saturn, Uranus, and Neptune.

Answer 1

Gas giant

Question 2

a small body from which a planet originated in the early stages of development of the solar system.

Answer 2

Planetesimal

Question 3

one of the highly dense planets nearest to the sun; Mercury, Venus, Earth and Mars.

Answer 3

Terrestrial planet

Question 4

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Answer 4

Protoplanet

Question 5

theory that a sun-centered, or heliocentric, model of the solar system.

Answer 5

Copernicus

Question 6

a rotating cloud of gas and dust from which the sun and planets formed; also any nebula from which stars and exoplanets may form.

Answer 6

Solar nebula

Question 7

a region of the solar system that is just beyond the orbit of Neptune and that contains dwarf planets and other small bodies made mostly of ice.

Answer 7

Kuiper Belt

Question 8

discovered the force gravity.

Answer 8

Newton

Question 9

Kepler’s second law,describes the speed at which objects travel at different points in their orbit.

Answer 9

Law of equal area

Question 10

Kepler’s third law,describes the relationship between the average distance of a planet from the sun and the orbital period of the planet.

Answer 10

Law of periods

Question 11

Kepler’s first law, states that each planet orbits the sun in a path called an ellipse, not in a circle.

Answer 11

Law of ellipses

Question 12

defined as a dwarf planet, orbits the sun in an unusually elongated and tilted ellipse. It is made up of frozen methane, rock, and ice, with an average temperature of –235 °C.

Answer 12

Pluto

Question 13

planets sometimes appeared to move backward in the sky relative to the stars – a pattern.

Answer 13

Retrograde motion

Question 14

thought that planets moved in small circles, called epicycles, as they revolved in larger circles around Earth.

Answer 14

Ptolemy