STUDY GUIDE FOR ASTRONOMY 100,
Schneider & Arny,
What is the definition of the astronomical unit (AU)?
How is a “light-year”
How many light-years away is the nearest star?
between the Earth and the Sun.
How far light travels in one year.
. The nearest
star is 4.2-4.3 light years away-
What are the names of the planets in our solar system?
What is a galaxy?
Mercury, venus, earth, mars, Jupiter, Saturn, Uranus, Neptune, Pluto, eris, ceres
A galaxy is a massive system of stars, gas, and dark matter held together by
their mutual gravity. Typical galaxies have a mass between about 10^7 and
10^13 solar masses. The milky way is our galaxy, which is usually capitalized.
About how many stars are in a typical galaxy?
How big across is our Milky Way
Is our galaxy part of any larger grouping of galaxies?
The milky way galaxy has between 200-400 billion stars.
100 times the diameter.
The milky way is part of a collection of galaxies called the local group. It is local,
because it is one we inhabit.
It contains 4 dozen galaxies with a 3 light year
Be able to express numbers in scientific notation, and be able to do simple unit
conversions, given the conversion factor.
5. What is the scientific method?
What makes a valid scientific theory?
The procedure by which scientists construct their ideas about the universe and
its contents, regardless of whether those ideas concern stars, planets, living
things, or matter itself.
Once a hypothesis has been thoroughly tested and
verified, it may be termed a valid scientific theory or a law.
6. What force holds the planets in orbit?
What force holds the electron in the atom?
Gravity of the sun holds the planets in orbit.
electrons are attracted to the nucleus
Their opposite charges attract each other.
7. Why are different constellations seen at different times of the year?
A constellation is a recognized grouping of stars.
because the earth orbits the sun,
we are rotating and see different parts of the night sky each night.
As seen from Earth, in which directions do stars rise and set?
Why does this
What are “circumpolar stars”?