7: Other Worlds - An Introduction to the Solar System

Question 1

a stony or metallic object orbiting the Sun that is smaller than a planet but that shows no evidence of an atmosphere or of other types of activity associated with comets

Answer 1

asteroid

Question 2

a small body of icy and dusty matter that revolves about the Sun; when it comes near the Sun, some of its material vaporizes, forming a large head of tenuous gas and often a tail

Answer 2

comet

Question 3

gravitational separation of materials of different density into layers in the interior of a planet or moon

Answer 3

differentiation

Question 4

AKA jovian planets - Jupiter, Saturn, Uranus, and Neptune in our solar system + planets of roughly that mass and composition in other planetary systems, composed primarily of ice, liquid, gas - no solid surface, only a small, dense core

Answer 4

giant planets

Question 5

time required for half of the radioactive atoms in a sample to disintegrate

Answer 5

half-life

Question 6

a small piece of solid matter that enters Earth’s atmosphere and burns up, popularly called a shooting star because it is seen as a small flash of light

Answer 6

meteor

Question 7

a portion of a meteor that survives passage through an atmosphere and strikes the ground

Answer 7

meteorite

Question 8

objects, from tens to hundreds of kilometers in diameter, that formed in the solar nebula as an intermediate step between tiny grains and the larger planetary objects we see today

Answer 8

planetesimals

Question 9

process by which certain kinds of atomic nuclei decay naturally, with the spontaneous emission of subatomic particles and gamma rays

Answer 9

radioactivity

Question 10

the cloud of gas and dust from which the solar system formed

Answer 10

solar nebula

Question 11

Mercury, Venus, Earth, and Mars (sometimes the Moon is included in the list) - relatively small planets with solid surfaces composed of rock and metal

Answer 11

terrestrial planets

Question 12

studying how the planets work by comparing them with one another

Answer 12

comparative planetology

Question 13

internal forces on terrestrial planets that reshape their crust, as the result of a hot interior - eruption of mountain ranges, volcanoes, etc.

Answer 13

geological activity

Question 14

planets in exoplanetary systems that are intermediate in size between our terrestrial and giant planets

Answer 14

superearths

Question 15

flattened, spinning clouds of gas and dust surrounding young stars - akin to solar nebula

Answer 15

circumstellar disks