Review Questions for Exam 1 in class.

This "preview" version of the review sheet will be updated to reflect material actually covered a few days before Exam 1.

These questions are intended to make you think about the relevant topics for the exam. They are not necessarily the exam questions themselves.

The exam will consist of about 30 multiple choice questions and 4 or 5 short answer questions. The questions will primarly address topics covered in the lectures and the lecture notes should be your primary guide to preparing for the test. The readings in the textbook should help clarify the lecture notes. The test will also contain a few general questions from the web readings below.

Note: All relevant equations will be provided at the top of the exam.

The relevant chapters in the text are:
The Cosmic Perspective -- Chapter 1 (all), Chapter 2, Chapter S1 (only the parts directly relevant to the lectures).

How long has the universe been in existence? What fraction of that time has the Solar System been around? What were the only elements present shortly after the Universe formed? Where did the rest of the elements in the periodic table come from? After 14 billion years of elemental synthesis, how much of a contamination of heavy elements has the universe managed to produce? How quickly, relatively speaking, did life originate on the Earth (very early on)? How long, relatively speaking, did it take for that life to become complex (a long time)? How long have humans been around compared with the age of the Universe?

What is a galaxy? Roughly how many stars does a galaxy contain? What is the name of the galaxy which we call home? What does it look like from the outside? What is the typical density of material in intergalactic space? How much denser is the local environment (e.g. the air in this room)? What is the temperature in intergalactic space?

How limited is the range of human vision relative to the entire electromagnetic spectrum? What sorts of phenomena can be observed by looking at the universe at wavelengths of light which are beyond the range of human vision?

What means do astronomers have to overcome the shortness of a human lifetime relative to the age of the Universe? What is meant by "lookback time"? What is the speed of light in km/s? Why when we observe distant objects do they appear as they were in the distant past?

In a scale model of the Solar System with the Sun the size have a basketball approximately how far away do you place the Earth? the nearest star? Make sure you know how to express and work with (multiply in particular) numbers in scientific notation.

What is the difference between the "physical" size of an object and its "angular" size? How does angular size of a particular object change as its distance from you changes? How do you measure the angular separation between two stars?

What is the difference between a constellation and an asterism? How many constellations are there? What does a constellation represent to a modern astronomer? How are stars named within each constellation? How are stars assigned magnitudes to represent their brightness? What is the magnitude of a star which is 100 times fainter than a 3rd magnitude star? how about 10,000 times brighter? How many stars can you see without the aid of a telescope?

How do we use the celestial sphere to approximate our view of the Universe from the Earth? How are the celestial poles and equator defined? How does the position of the pole and equator in the sky depend on your position on the Earth? How does your view at the Earth's Equator differ from your view from the North Pole? Which way do you face (North, South, East, or West) to see the celestial pole here in Charlottesville? Does that answer depend on whether you are in the Northern or Southern hemisphere?

How do you easily measure your latitude on the Earth? What are circumpolar stars? Where do you find them in the sky. If you could see the celestial equator in the sky what would it look like? How would it change from hour to hour and night to night? What is the name of the apparent path followed by the Sun around the sky? By how much do the rising and setting times of the stars change each day due to this motion?

What is the ecliptic? How are the ecliptic and zodiac related? What is meant by Solstice and Equinox? How far does the Sun get (in degrees) from the Celestial Equator at the Solstice or Equinox? Where does this number come from? What defines the instant when Spring or Fall begins? Why is it cold in Winter (2 reasons)? In what month is the Earth closest to the Sun? How are the seasons different between the Northern and Southern hemispheres?

Why is Polaris only temporaily the "North" star? How long does it take the Earth's rotation axis to complete a precession cycle? By how many degrees can the Earth's pole shift amongst the stars?

When does the first quarter moon rise? When does the full moon set? What is the difference between a Synodic and Sidereal month? between a Solar and Sidereal day? What do the previous two questions have in common?

What is the difference between a lunar and solar eclipse? What is the phase of the Moon for each of these types of eclipses? What is the phase of the Earth as seen from the Moon during a total solar eclipse (draw a picture!)? Why don't eclipses occur at every new and full moon. How long does a solar eclipse last for an observer at a fixed location on the Earth? Where do you have to be on the Earth to see a total solar eclipse? If you pick a spot on Earth and wait around for a solar eclipse to happen, how long will your wait typically be? What sorts of things do you see during a total solar eclipse? How about a partial one?

How about a total lunar eclipse? Have more people seen total solar eclipses or total lunar eclipses? How long does a lunar eclipse last? Why doesn't the Moon disappear entirely during a total lunar eclipse? What sorts of things do you see during a total lunar eclipse?

What's the difference between an annular and total solar eclipse? What's the difference between the "umbra" and "penumbra" of a shadow and what does this difference have to do with partial and total eclipses? Where are the Earth and Moon in their orbits (it terms of their distances from each other - i.e. close or far) when an annular solar eclipse occurs?

What is the difference between the Tropical and Sidereal year? Why do we care? Why does the calendar contain leap years? Why is it not sufficient to have a leap year once every four years? Will the year 2100 be a leap year? Do people on other planets need leap years?

How do the motions of planets differ from the motions of stars on the night sky? How bright are the planets compared with the stars? What is the difference between an "inferior" and a "superior" planet? When is the best time to see each of these classes of planet? In what configuration (conjunction, opposition, etc.) is the Earth closest to a superior planet? In what configuration is it farthest from an inferior planet?