Planet Vocadulary

Question 1

Orbit

Answer 1

the circular path of an object as it revolves around another object.

Question 2

Solar system

Answer 2

a system of objects that revolve around a star.

Question 3

Galaxy

Answer 3

a group of solar systems, dust, and gas held together by gravity; our solar system is part of the Milky Way galaxy

Question 4

Universe

Answer 4

everything that exists in, on and around the Earth

Question 5

Satellite

Answer 5

an artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.

Question 6

Impact crater

Answer 6

a crater on a planet or moon caused by the impact of a meteorite or other object, typically circular with a raised rim.

Question 7

Rotation

Answer 7

turning around on an axis; spinning

Question 8

Revolution

Answer 8

an instance of revolving.

Question 9

Season

Answer 9

a period of the year determined by the position of Earth as it revolves around the sun

Question 10

Equinox

Answer 10

the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about September 22 and March 20).

Question 11

Solstice

Answer 11

either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.

Question 12

Mare

Answer 12

are large, dark, basaltic plains on Earth’s Moon, formed by ancient volcanic eruptions

Question 13

Eclipse

Answer 13

an event that happens when the shadow of an object in space falls on the surface of another object

Question 14

Umbra

Answer 14

the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse.

Question 15

Penumbra

Answer 15

the partially shaded outer region of the shadow cast by an opaque object.

Question 16

Astronomical Unit

Answer 16

a unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.

Question 17

Ellipsis

Answer 17

a closed plane curve generated by a point moving in such a way that the sums of its distances from two fixed points is a constant

Question 18

Terrestrial Planet

Answer 18

A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals.

Question 19

Gas giant

Answer 19

a large planet of relatively low density consisting predominantly of hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune.

Question 20

Asteroid

Answer 20

a small object made of rock or metal that orbits the sun

Question 21

Comet

Answer 21

a body of ice and dust that travels in a long narrow orbit around the sun

Question 22

Meteor

Answer 22

a small body of matter from outer space that enters the earth’s atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.

Question 23

Meteorite

Answer 23

a piece of rock or metal from space that strikes Earth’s surface

Question 24

Geocentric

Answer 24

having or representing the earth as the center, as in former astronomical systems.

Question 25

Heliocentric

Answer 25

having the sun as the center

Question 26

Gravity

Answer 26

having the sun as the center

Question 27

Tide

Answer 27

is the cycle of rising and falling of the surface of bodies of water caused by the attraction of the moon and the sun.

Question 28

Waxing

Answer 28

the moon at any time after new moon and before full moon, so called because its illuminated area is increasing

Question 29

Waning

Answer 29

the moon at any time after full moon and before new moon

Question 30

Gibbous Moon

Answer 30

Gibbous refers to the shape, which is less than the full circle of a Full Moon, but larger than the semicircle shape of the Moon at Third Quarter. With some exceptions, the Waxing Gibbous Moon rises during the day, after noon.

Question 31

Crescent moon

Answer 31

A crescent is a thin, curved shape that’s thicker in the middle and tapers to thin points at each end, like the little sliver of moon you might notice in the sky. Crescent was first used to describe the shape of the waxing, or growing moon, and if you listen closely you can hear its similarity to increase.

Question 32

New moon

Answer 32

the moon’s phase when it is in conjunction with the sun so that its dark side is toward the earth also.

Question 33

Quarter moon

Answer 33

Either of the intermediate stages between the new and full moons. In spite of the name, half of the Moon’s visible portion is lit up during a quarter moon.

Question 34

Perihelion

Answer 34

the point in the orbit of a planet, asteroid, or comet at which it is closest to the sun.

Question 35

Aphelion

Answer 35

the point in the orbit of a planet, asteroid, or comet at which it is furthest from the sun