Earth and space

Question 1

Astronomy

Answer 1

The study of the universe and everything in it

Question 2

Geocentric

Answer 2

A theory of the structure of the solar system in which the Earth was thought to be at the centre.

Question 3

Heliocentric

Answer 3

A theory of the structure of the solar system where the Sun is at the centre.

Question 4

Universe

Answer 4

Everything that exists, including planets, stars, galaxies and all forms of matter and energy.

Question 5

Big Bang

Answer 5

Most scientists believe that the universe began with an explosion - the Big Bang - about 14 billion years ago.

Question 6

Galaxy

Answer 6

A large group of stars, dust, gas and dark matter held together by gravity.

Question 7

Antimatter

Answer 7

The mirror image of matter. Every particle of matter has a corresponding particle of antimatter. When they meet they destroy each other and are converted into pure energy.

Question 8

Hypothesis

Answer 8

Collection of ideas that seem to explain what is observed =>predictions that can be tested

Question 9

Models

Answer 9

Describes reality based on hypothesis that have withstood observational and experimental tests=>explains with mathematics properties and behaviors of some object or phenomenon

Question 10

Theory

Answer 10

Series of well tested hypothesis that together form a self-consistent and accurate description of nature=>capable of making predictions that can be tested and verified by anyone

Question 11

Laws

Answer 11

Proven theories that have stood the test of time and have broad applicability

Question 12

Constellation

Answer 12

Some stars are grouped together there are eighty eight groups

Question 13

Ecliptic plane

Answer 13

Plane of earths orbit around the sun (squashed circle)

Question 14

Terrestrial planets

Answer 14

Planets made up of rock. In our solar system, the terrestrial planets are the four inner planets.

Question 15

Gas giants

Answer 15

The outer planets in our solar system are called gas giants because they are mainly made of gases hydrogen and helium.

Question 16

Gravity

Answer 16

non-contact force of attraction between objects. There is a gravitational pull between all masses.

Question 17

Force field

Answer 17

A region in space where an object feels a force.

Question 18

Solar system

Answer 18

Our solar system includes the Sun and all the objects that orbit around it due to its gravity, including the Earth.

Question 19

Celestial body

Answer 19

Any natural body outside of the Earth’s atmosphere. There are various celestial bodies, including planets, stars, moons, comets and asteroids.

Question 20

Planet

Answer 20

An object that is in orbit around a star, has sufficient mass to assume a nearly round shape, and has become gravitationally dominant. This means that it can clear the space debris in its orbit.

Question 21

Moon

Answer 21

A natural satellite that orbits a planet.

Question 22

Star

Answer 22

A ball of heat radiating gas that is held together by gravity. Stars contain mostly hydrogen as well as helium and smaller amounts of other elements.

Question 23

Sun

Answer 23

The star that lights and heats our planet. The Sun is powered by a fusion reaction at its core.

Question 24

Light-year

Answer 24

The distance that light travels in one year. Light-years are often used in astronomy to describe the distance to faraway stars and galaxies.

Question 25

Asteroid

Answer 25

Lumps of rock that orbit the Sun but are too small to be classified as planets. There are three types of asteroids, divided based on what they are made up of:
C-type asteroids are made up of carbon compounds;
S-type asteroids are made up of stony material;
M-type asteroids are mostly made of metals, such as iron.

Question 26

Comet

Answer 26

A celestial body that orbits the Sun, made up of a nucleus, a coma and one or more tails. The nucleus of a comet is made up of dust and ice. The coma (a fuzzy outline or atmosphere caused by the Sun’s radiation) is made up of carbon dioxide, dust and water vapour. The tail is made up of gas and dust produced by the nucleus.

Question 27

The Big Bang

Answer 27

It started as small thing the size of a mm and it had the energy of a supercharged black hole and it exploded and caused the Big Bang