definitions

Question 1

universe

Answer 1

Universe= everything that exists, including all energy, matter and space.

Question 2

celestial object

Answer 2

Celestial object= a naturally occurring physical entity, association, or structure that exists in the observable universe.

Question 3

luminous

Answer 3

Luminous=Luminosity is the total amount of energy produced by a star per second which is measured by comparing it with the luminosity of the sun, which is assigned a luminosity of 1.

Question 4

star

Answer 4

Star=massive collections of gases held together by their own gravity and emitting huge amounts of energy.

Question 5

planet

Answer 5

Planet=Planets are large celestial objects that revolve around a star.

Question 6

moon

Answer 6

Moon=The moon is a type of satellite. Earth has one satellite called the moon.

Question 7

rotation

Answer 7

Rotation=the rotation of Planet Earth around its own axis.

Question 8

revolution

Answer 8

Revolution=the rotation around the sun.

Question 9

solar system

Answer 9

Solar system=the collection of eight planets and their moons in orbit around the sun, together with smaller bodies in the form of asteroids, meteoroids, and comets.

Question 10

orbit

Answer 10

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

Question 11

satellite

Answer 11

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

Question 12

nebula

Answer 12

Nebula=a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.

Question 13

auroras

Answer 13

Auroras=a natural electrical phenomenon characterized by the appearance of streamers of reddish or greenish light in the sky, usually near the northern or southern magnetic pole.

Question 14

A.U. and ly

Answer 14

1 A.U. - (150 000 000 km) 1 ly - (9.46 x 1012 km)

Question 15

inner planets

Answer 15

Inner planets

• Mars, Venus, Mercury & Earth
• known as terrestrial planets, as they have a solid rocky core.

Question 16

outer planet

Answer 16

Outer planets

• Jupiter, Saturn, Uranus & Neptune
• known as gas giants, as they are composed mainly of gases and liquids.

Question 17

asteroid belt

Answer 17

Asteroid belt=The asteroid belt is a region of space between the orbits of Mars and Jupiter where most of the asteroids in our Solar System are found orbiting the Sun.

Question 18

meteor

Answer 18

Meteor= in atmosphere

Question 19

meteoroid

Answer 19

Meteoroid= in space

Question 20

meteorite

Answer 20

Meteorite= hitting the earth

Question 21

asteroid

Answer 21

Asteroid=Asteroids are composed of rock and metal. Although they orbit the sun, they are too small to be considered planets. Most asteroids lie in the asteroid belt, between Mars and Jupiter.

Question 22

comet

Answer 22

Comet=Large chunks of ice, dust and rock that orbit the sun and range in size from less than 100 m to 40 km across.

Question 23

waxing vs waning

Answer 23

Waxing vs. Waning= Increase in size - WAXING Decrease in size - WANING

Question 24

gibbous and crescent

Answer 24

Gibbous vs. Crescent= Gibbous - more than ½ Crescent - less than ½

Question 25

solstice

Answer 25

Solstice vs. Equinox= Solstice - June 21(longest day of the year) and December 21 (shortest day of the year)

Question 26

equinox

Answer 26

Equinox - When the amount of daylight = the amount of darkness in a day March 21 (Vernal) & September 21 (autumnal)

Question 27

galaxy

Answer 27

Galaxy= collections of millions to hundreds of billions of stars, planets gas and dust, measuring up to 100 000 light years across.

Question 28

elliptical galaxies

Answer 28

``` Elliptical Galaxies Spherical or flattened oval Older galaxies Very little gas,dust or young stars Half of all galaxies we see ```

Question 29

spiral & barred spiral galaxies

Answer 29

``` spiral & barred spiral ↳regular Flattened disk Central bulge 2-4 spiral arms ↳barred Central bulge w spiral arms that trail from the ends of the bars ```

Question 30

lenticular galaxies

Answer 30

lenticular (sombrero) | Central bulge no spiral arms

Question 31

irregular galaxies

Answer 31

Irregular no definite shape, no arms, no central nucleus 10% of all galaxies

Question 32

black holes

Answer 32

Black holes= A region of space having a gravitational field so intense that no matter or radiation can escape. Caused by : Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. Stars running out of fuel, they cool down and collapse. The gravitational collapse of stars.

Question 33

event horizon

Answer 33

Event horizon= The point of no return oOOoooOOoo. The path of which objects can be eaten by a black hole. The shell that is the cosmo point of no return.