AST-111
Unit #2: Study Guide
1) Describe the scientific method.
2) Generally the planets move eastward in relation to the background stars overtime, then one night you
notice Mars has moved westward, what’s happening?
3) Who was the first person to explain retrograde motion? What was his explanation?
4) What is the cause for retrograde motion?
5) Galileo and Copernicus both have valid specific observations to prove their theories about planetary
motion, but according to the scientific method, what did they lack?
6) What was the name of the Greek scientist who first calculated the size of the earth? Explain how he
calculated this.
7) From #6, what astounding discovery did he make when he did this?
8) Who first hypothesized that the planets orbited in elliptical orbits? What led him to believe this?
9) Kepler knew the planets orbited in elliptical orbits, but what piece of the puzzle was he missing?
10) What famous physicist "discovered" the laws of gravity?
11) What are the three laws he came up with?
12) If I ran my head into the wall, and my head had a force of 1000N on the wall, what sort of force will the
wall apply to my head?
13) How would the Earth move through space if the sun disappeared?
14) If a planet is at perihelion what can you say about its speed in relationship to when it is at aphelion?
1
15) Fill in the electromagnetic spectrum going from low energy on the left, to high energy on the right (I
have filled one in to get you started)?
Visible
Light
Roy G. Biv
16) What part of the electromagnetic spectrum do most astronomers study?
17) Which law applies to the color of stars and their temperature?
18) Which star is hotter, a blue star or a yellow star?
19) Which star is cooler, an orange star or a red star?
20) What branch of astronomy studies objects whose blackbody curves peak in the short radio portion of the
spectrum?
21) Which portion of the spectrum does our sun’s energy peak in?
22) If a star's spectrum is shifted towards the red, what do we know about its motion relative to us?
23) If the class was outside during a nice spring evening, and looked at the spectrum of a first quarter moon,
through a cloud, which one of Kirchhoff's laws would we be using?
24) What sort of spectra does the sun emit, as seen from outer space?
25) Which spectra does the Orion nebula emit (a cloud of gas where stars are born)?
26) Waking up one morning, a radio astronomer sees that it is cloudy. Does he still go to work? Explain.
27) Who discovered cosmic radio waves?
28) Name some of the other advantages to radio astronomy?
29) Who's equation do we use to figure out our chances of finding extraterrestrial life?
30) What government-funded program is currently looking for extraterrestrial life?
2
Fill in the blank
1) This type of telescope has a mirror in it. ______________
2) The__________ part of an energy wave describes how bright a light wave is.
3) __________ can tell you how much or how little detail you can see through a telescope.
4) The eastward motion of the planets throughout the zodiac constellations is called __________.
5) The westward motion of a planet is called ____________.
6) Copernicus believed in the __________ or sun-centered solar system.
7) The squishiness of an ellipse is known as its __________.
8) When an outer planet is at the middle of its retrograde motion, its position relative to the earth is called
__________.
9) The __________ of a telescope is the distance between the lens and the eyepiece.
10) The __________ part of the electromagnetic spectrum is made up of R O Y G B I V.
11) The __________ law states: if a planet is three times further away from the sun than the earth the
gravitational pull of the sun on that planet would be 1/9th as much.
12) When a person goes to the tanner, the tanning booth blasts them with __________ radiation.
13) Up until Copernicus and Galileo's time, most people believed in a __________ model of the universe.
3
True or False
1)
_____ As far as stars go a red appearing star is hottest of stars.
2)
_____ Everything in the Milky Way galaxy emits visible light.
3)
_____ Before Christopher Columbus, no one knew the earth was round.
4)
_____ In the period of the 1600's new ideas and theories as to the model of the universe were openly
taught and accepted.
5)
_____ We can detect all forms of electromagnetic radiation with our eyes.
6)
_____ The square of an object’s orbital period is directly proportional to the cube of its distance from
the sun.
7)
_____ Life exists on other planets, and in other star systems in the Milky Way galaxy according to
Drake.
8)
_____ The major restriction for the study of astronomy is the fact that we can't go there and touch a star
or enter stellar matter.
9)
_____ Brahe was a great theoretical astronomer.
10)
_____ Astrology is a fact-based science.
11)
_____ Galileo invented the telescope.
12)
_____ The first person to make theories on gravity was Newton.
13)
_____ If a star is moving towards us, its spectrum will be blue shifted.
14)
_____ Radio astronomy can be done during the day.
15)
_____ Optical telescopes can be used only at night.
16)
_____ An object at rest will stay at rest unless acted upon by an outside force.
17)
_____ Cosmic X-ray and Gamma ray can be observed using telescopes on earth’s surface.
18)
_____ Short wavelength electromagnetic energy has low energy.
19)
_____ All types of electromagnetic energy travels at 300,000 km/s in space.
4
Telescope Identification
1) For the above illustration, what type of telescope is this?
2) What type of aberration can this telescope suffer from?
3) Who invented this type of telescope?
4) What type of optics does it use to gather light?
5) For the above illustration, what type of telescope is this?
6) Who invented this type of telescope?
7) What is the name of the largest telescope of this type?
8) What type of aberration can this telescope suffer from?
9) What type of optics does it use to gather light?
10) What is the term used to describe the distance from the objective lens/mirror to the eyepiece?
5