Week 1

Put the following in order from smallest to largest in size.

your room, Earth, the Sun, the Solar System, the Milky Way Galaxy, the universe

Light travels 3 x 105 kilometers every second. That number in words is

300,000 kilometers

The laws of nature (as determined by scientists)

are constructed from many observations, hypotheses, and experiments apply both on Earth and among the stars can never, ever change once they are written down in textbooks

If you were giving your alien friend directions from Earth to Saturn, what unit of length would be most convenient?

astronomical units

The way scientists know that a hypothesis in astronomy is a reasonable description of nature is to

do experiments and observations about the predictions of the hypothesis

By the term universe, astronomers mean

everything that we can observe

If you were giving your alien friend directions from Earth to Sirius (a relatively nearby star), what unit of length would be most convenient?

light years

Which of the following is the Earth located in?

the Solar System the Milky Way Galaxy the Local Group of galaxies the Virgo supercluster

The Astronomical Unit (AU) as defined by astronomers is

the average distance between the Earth and the Sun

A light year is

the distance light travels in one year