Space

Question 1

what are three celestial objects?

Answer 1

• planets
• moon
• stars

Question 2

Four methods of measuring the universe

Answer 2

1. radar
2. corner reflectors
3. Parallax or Triangulation
4. Colour, Temperature, Brightness of celestial object

Question 3

About radar:

Answer 3

• works for moon and planets relatively close to Earth
• Measures the time it tale for the radar waves sent from Earth to be reflected by the moon or planets.
• Assumes radio waves are travelling at the speed of light
• Radar measurements are ACCURATE to the edge of out solar system (100 million kms)

Question 4

About corner reflectors:

Answer 4

• Works only for Earths moon
• Corner reflectors were left on the moon during the moon landing in 1969
• works by sending a laser light to the moon that is reflected back.
• Assumes laser travels at the speed of light.

Question 5

about Parallax or Triangulation:

Answer 5

• involves viewing an object from two different angles.
• The distance between the two different positions is called the baseline
• The further away the object is the smaller the angle is
• works for any object that can be seen e.g. star, planet,moon