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Flashcards in Definitions Deck (27):
1

Orbit

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

2

Solar system

a system of objects that revolve around a star

3

Universe

Space is full of galaxies, stars, planets, and their moons. All of these things together are known as the universe. The universe is bigger than we can imagine

4

Satellite

A satellite is something that travels in a circle. At the center of that circle is a planet. We have launched many man-made satellites around the Earth. These satellites can take pictures of Earth. They also send and receive television and phone signals

5

Galaxy

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

6

Impact crater

The Moon’s surface is covered with bowl shaped holes called craters. The Barringer Crater was made by a meteor that struck Earth thousand of years ago

7

Rotation

the spinning of a celestial body, such as a planet, around an axis

8

Revolution

the orbiting of an object around another object

9

Season

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

10

Eclipse

an event whereby one astronomical body passes between two other astronomical bodies

11

Equinox

Same amount of light and darkness

12

Astronomical units

the mean distance from the center of the Earth to the center of the sun (about 149.6 million kilometers); used to measure distances in the solar system

13

Asteroid

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

14

Comet

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

15

Meteor

a streak of light in the sky that forms when a piece of rock from space burns up in Earth's atmosphere

16

Meteorite

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

17

Geocentric

having the Earth as the center

18

Heliocentric

having the sun as the center

19

Gravity

a force that exists between any two objects that have mass

20

Tide

the rise and fall of the ocean's surface levels due to the gravitational pull of the sun and moon

21

Waxing moon

The gradual increase of the illuminated surface of the moon

22

Wanning moon

The gradual decrease in the illuminated surfaces of the moon

23

Gibbous moon

More than half but less than fully illuminated

24

Cresent moon

The illuminated surface is less than a quarter illuminated

25

Full moon

The entire surface of the moon is illuminated

26

New moon

The entire of the moon is not illuminated

27

Quarter moon

Half of the moon surface is illuminated