P06.10 Redshift and Expansion

What is a solar system?

• A collection of stars

• A collection of planets

• A collection of objects orbiting a star

• A collection of stars orbiting a black hole

What is a satellite?

• Any object orbiting another object

• Any object orbiting a bigger object

• A man made device put into space

• A man made device orbiting an object

Which of the following is false?

• Comets have elliptical orbits.

• Comets are made from rock and ice.

• Asteroids are non-spherical.

• Asteroids have easily predictable orbits.

What is the geocentric theory?

• Everything in the universe orbits Earth

• Everything in our Solar System orbits Earth

• That everything orbits the geocentre of the universe

• That everything orbits the geocentre of the our Solar System.

What proof did Galileo have for the heliocentric theory?

• Everything in the universe orbits the Sun

• Everything in our Solar System orbits the Sun

• Jupiter’s moons orbit the Sun

• Jupiter’s moon don’t orbit Earth

Which is true for a comet as it becomes closer to the Sun?

• It travels at the same speed.

• It crashes into the Sun.

• Its velocity increases.

• Its velocity decreases.

Why do we place telescopes in space?

• Because it is always night-time in space.

• So the telescope is closer to what it is observing.

• Because some waves are absorbed by our atmosphere.

• Because telescopes on Earth take up too much space.

What is the Doppler Effect?

• The apparent change in wavelength and frequency of a wave given out from a moving object.

• The apparent change in speed of a wave given out from a moving object.

• The apparent change in wavelength or frequency of a wave given out from a moving object.

• When light from galaxies becomes red.

What is redshift?

• The apparent change in colour of light when an object moves.

• The apparent change in frequency and wavelength from a light source as it moves towards us.

• The apparent change in frequency and wavelength of a wave from a light source as it moves.

• When an object appears more red.

Light from a galaxy is redshifted. One half of the galaxy is more redshifted than the other. What does this tell us?

• The galaxy is moving away from us

• The galaxy is rotating and moving towards us

• The galaxy is rotating and moving away from us.

• The galaxy is rotating.