If you could "zoom out" all the way, this is what the universe would look like. Stars cluster into galaxies; galaxies cluster into galaxy clusters; these form superclusters; and the superclusters constitute the giant filaments in the picture above, forming an intricate spider-web fabric separated by giant voids

“I want to put a ding in the universe” — Steve Jobs

“We do not appear to have been visited by aliens. I’m discounting the reports of UFOs. Why would they appear only to cranks and weirdos?” — Steven Hawking

The last two units of ASTRO 101 usually involve stars and cosmology (and sometimes aliens, if there’s time for that). These are, respectively, the hardest and easiest parts of the class.

Stars are fire. And a pain to study, because you would never have thought that a giant explosion could be so complicated. Generally, the study of stars first focuses on Mr. Special, the sun. As you may have gathered from your life experience, the sun is somewhat important for life on earth. Understanding Mr. Special is simply a matter of rote memorization (go here for help with that). Use the techniques to stick the textbook facts in your noggin. Then you must understand two more things: the different classes of stars and their life-cycles.

Star class is determined solely by star mass: the more mass, the hotter and brighter the star and the more spectacular its demise. You must know the significance of the following things: the star’s mass; its heat/color (the hotter it is, the bluer it will be and the cooler it is, the redder it will be), its size (size and mass are unrelated), and where it is in its life. You must know the fate of small and medium stars; and you must know that high-mass stars go really, really bang when they die. They go supernova. All of the gas in the star wafts out into space as a nebula. All that’s left is a white neutron star (study this). If the neutron star is massive enough, it may eventually collapse into a black hole. Are black holes like cosmic vacuum cleaners? No. Do they lead to alternate dimensions? Maybe. These are the sorts of things you must glean from your notes and textbook.

Then there’s cosmology, the study of nothing less than the entire universe. On this topic, use your notes and textbook to flesh out the following concepts:

1. Big Bang Theory. You must know what it is, what theory came before it, and why scientists eventually accepted it.

2. Inflation Theory (Big Bang 2.0). You must understand our current understanding of universal origins. Realize that the galaxies are not flying away from each other, but that space itself is stretching and the galaxies are just along for the ride.

3. Dark matter. Understand what it is and how scientists “discovered it.”

4. Dark energy. This goes along with the Big Bang theory. Like dark matter, dark energy is an idea invented by scientists to make the equations work. Nevertheless, understand what it is and why scientists had to invent it.

5. The shape and curveature of the universe. Is our universe flat? Is it spherical? Is it saddle-shaped? Donut-shaped? These are actual questions that cosmologists ask. Understand them and understand what determines the shape of the universe and what the current consensus is. Note that the universe has neither an edge or a center (so much for “The Restaurant at the Edge of the Universe”).

6. The Fate of the universe. It seems that, left to its own devices, the universe falls apart. There are several theories. If the universe is too dense, Big Crunch Theory says that the cosmos will collapse and become rather uncomfortable; real estate will be valuable. On the other hand, if the universe is too diffuse, it will expand forever until everything freezes (Big Freeze Theory) or until entropy separates every atom from every other atom (heat death). Either way, the outlook isn’t brilliant. However, if the density of the universe is just right and the universe is flat, we’re in good shape.

If you are unfortunate, your professor may also include a discussion of extra terrestrials, alternate universes, the Twilight Zone, hob-goblins, elves, etc.

This is our solar system: all the planets are about the same size, they're always in a neat row, and they're always bunched up close to the sun; this makes it easy to take pictures

“The terrain is a bit unstable. No sign yet whether the air is breathable. And there seems to be no sign of intelligent life on this planet” — Buzz Lightyear, after coming to earth

The second unit of most astronomy classes involves an overview of our solar system. This is easy: think of the solar system as a big circle. Right in the middle is the sun; then there are four rocky, “terrestrial” planets; then there is an asteroid belt; then there are four large, gas planets, the “Jovian planets”; and finally there is the Kuiper Belt, a band of comets, chunks of rocks and ice, and small planetoids (like Pluto).

All you have to do is fill out and memorize a short check-list for each planet: (1) is it terrestrial or Jovian (rocky or gaseous)? (2) Is it large or small? (3) Where in the solar system is it? (4) What is its tilt? (5) How powerful is its magnetosphere (see your textbook for details)? (6) What is the structure of its atmosphere? (7) What is its overall structure? (8) How many moons does it have? (9) Does it have rings? (10) If it does have rings, what is its ring structure?

Just run through these questions and use your notes/textbook to answer them. You could draw a chart or create a map of the solar system with all of the above information on it; then you could simply study your map/chart for the exam.

Your professor may also require knowledge of several other things: (1) what are the Jovian moons, what is their basic structure, and why are they a big deal? (2) What is the structure of Jupiter’s rings and what are they called? (3) Which planets have we sent robots to (hint: Mars and Venus)? (4) What is the name of Jupiter’s Great Red Spot (hint: it’s called the Great Red Spot)? (5) What is Pluto made of (hint: we don’t know, but probably a mixture of ice and rock)? (6) What’s the structure of and the difference between meteors, meteoroids, meteorites, asteroids, and comets? (7) What are the major features we see on Mars?

“I don’t think you understand the demands of space-travel. It can take hours, days, even… several days” — Zidgel

Some students go supernova because they think ASTRO 101 is more challenging than going to the moon. But if you want to boldly go where no man has gone before and snatch an A in the class, read on.

ASTRO 101 is actually simple. It has four modules: (1) astronomy’s history and methods; (2) our solar system; (3) stars, nebulae, novae, and galaxies; and (4) cosmology, the study of the universe as a whole. Over the next two weeks I will post on each of these modules and how to ace them without ever doing the Captain Picard facepalm pictured above.

The first unit of ASTRO class usually deals with what astronomy is, its history, and the way astronomers work. Thus, all you have to do is understand the following concepts (you can use my memorization techniques described here):

1. Know the definition of astronomy.

2. Know the big names, what they did, and what they thought (e.g. Tycho and his star data, Kepler and his laws of planetary motion, Newton and his laws of gravitation, etc.). For a quick and easy primer on this, go here.

3. Know all the different types of radiation: radio wave, microwave, infared, visible, ultraviolet, etc. Know which ones are hotter and shorter and which ones are cooler and longer. For the 401 on this, go here.

4. Know how light works and how it interacts with atoms. Also know how light interacts with gas. This site gives an excellent overview.

5. Know how telescopes work; know the different kinds of telescopes (e.g. refractive, reflective, etc.).

6. Know the ways in which astronomers organize the sky such as the north-south coordinate system, the celestial spheres, etc.

7. Some classes may require that you know how the earth, sun, and moon interact and shine on one another. If so, understand the concepts of years, revolutions, months, lunar cycles, solar cycles, eclipses, seasons, axial tilt, and perihelion/aphelion. That’s all.