Earth In Space

Question 1

What is the definition of a comet?

Answer 1

Ice-covered rocky structure that orbits the sun

Question 2

What is the definition of an asteroid?

Answer 2

Very large rock found in space in the asteroid belt between mars & jupiter

Question 3

What is the definition of a moon?

Answer 3

Natural structure that orbits a planet

Question 4

What is the definition of a planet?

Answer 4

Structure in orbit around a star

Question 5

What is the definition of an orbit?

Answer 5

Elliptical path of structure travelling around star/planet

Question 6

What is the definition of a star?

Answer 6

Massive extra-terrestrial structure that emits light & radiation

Question 7

What are the functions of artificial satellites?

Answer 7

Communications
Observing earth
Weather monitoring
Astronomy

Question 8

What is gravity?

Answer 8

Force of attraction that exists between objects

Question 9

What does the force of gravity depend on?

Answer 9

Mass of objects - bigger objects, larger force of gravity

Distance between objects - force of gravity decreases as distance apart increases

Question 10

How do we calculate weight?

Answer 10

Weight = mass x gravity

Question 11

How are starts formed?

Answer 11

1. Cloud of hydrogen comes together under force of gravity
2. As hydrogen is compressed, becoming very dense; its temperature rises to many million degrees
3. At high temperatures, nuclear fusion occurs & hydrogen nuclei combine to form heavier nuclei such as helium
4. This nuclear fusion emits light & heat/radiation

Question 12

What is 1 light year?

Answer 12

Distance travelled by ray of light in 1 year

Question 13

What is the definition of the red shift?

Answer 13

Phenomenon of light spectrum different galaxies being shifted towards red end of spectrum

Question 14

The further away a galaxy…

Answer 14

The larger the red-shift

Question 15

What is the Big Bang Theory?

Answer 15

Universe started as tiny point, called singularity , about 14 billion years ago
Big Bang represents massive cosmic explosion that expelled matter & energy in all directions out from its central point
Over millions of years, gravity pulled the scattered together together to form galaxies , stars, a planets & moons
Forces involved area causing universe & space to continue to expand
Evidence of this is red-shift of distant galaxies

Question 16

What is an alternative theory to the Big Bang Theory?

Answer 16

The Steady State Theory - proposes that universe hasn’t changed so much over time & had no significant beginning.
Suggests new matter is constantly created as universe expands. Most scientists don’t support theory as red-shift can’t be explained