Planet Vocabulary

Question 1

Orbit

Answer 1

The curved path of a celestial object or spacecraft around a star, planet, or moon, especially a periodic elliptical revolution.

Question 2

Solar system

Answer 2

The collection of eight planets and their moons in orbit around the sun, together with small bodies in the form of asteroids, meteoroids, and comets.

Question 3

Galaxy

Answer 3

A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.

Question 4

Universe

Answer 4

All existing matter and space considered as a whole; the cosmos. The universe is believed to be 10 billion light years in diameter and contains a vast number of galaxies; it has been expanding since its creation in the Big Bang about 13 billion years ago.

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 a meteorite or other object, typically circular with a raised rim.

Question 7

Rotation

Answer 7

The action of rotating around a axis or center.

Question 8

Revolution

Answer 8

The movement of one object around a center or another object.

Question 9

Season

Answer 9

Each of the four divisions of the years(spring, summer, fall/autumn, and winter) marked by particular weather patterns and daylight hours, resulting from the earth’s changing position with regard to 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 it’s highest or lowest point in the sky, marked by the longest and shortest days.

Question 12

Mare

Answer 12

A large, level basalt plain on the surface of the moon, appearing dark by contrast with highland areas.

Question 13

Eclipse

Answer 13

An obscuring of the light from one celestial body by the passage of another between between the observer or between it and it’s source of illumination.

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 experience the total phase of an eclipse.

Question 15

Penumbra

Answer 15

The partially shaded 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 earth to the center of the sun.

Question 17

Ellipse

Answer 17

A regular oval shape.

Question 18

Terrestrial planet

Answer 18

A planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets closest to the sun, I.e. Mercury, Venus, Earth, and Mars.

Question 19

Gas giant

Answer 19

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

Question 20

Asteroid

Answer 20

A small rock body orbiting the sun. Large numbers of these, ranging in size from nearly 600 miles(1,000 km) across(Ceres) to dust particles, are found(as the asteroid belt) especially between the orbit of Mars and Jupiter, though some have more eccentric orbits, and a few pass close to the earth or center of the atmosphere as meteors.

Question 21

Comet

Answer 21

A celestial object consisting of a nucleus of and ice and, when near the sun, a “tail” of gas and dust particles pointing away from 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 meteor that survives its passage through the earth’s atmosphere such that part of it strikes the ground. More than 90% of meteorites are rock, while the remainder consist wholly or partly of iron and nickel.

Question 24

Geocentric

Answer 24

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

Question 25

Heliocentric

Answer 25

Having or representing the sun as a center, as in the accepted model of the solar system.

Question 26

Gravity

Answer 26

The force that attracts a body toward the center of the earth, or toward any physical body having mass.

Question 27

Tide

Answer 27

The alternate rising and falling of the sea, usually twice in each lunar day at a particular place, due to the attraction of the moon and sun.

Question 28

Waxing

Answer 28

The right side of the moon is illuminated.

Question 29

Waning

Answer 29

The left side of the moon is illuminated.

Question 30

Gibbous moon

Answer 30

The moon when it’s having the observable illuminated part greater then a semicircle and less than a circle.

Question 31

Crescent moon

Answer 31

The curved sickle shape of the waxing or waning moon.

Question 32

Full moon

Answer 32

The phase of the moon in which it’s whole disk is illuminated.

Question 33

New moon

Answer 33

The phase of the moon when it is in conjunction with the sun and invisible from the earth, or shortly thereafter when it appears as a slender crescent.

Question 34

Quarter moon

Answer 34

When half of the visible moon from earth is illuminated.

Question 35

Perihelion

Answer 35

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

Question 36

Aphelion

Answer 36

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