Astronomy 101 - Some Hints for Study and Quiz Preparation

This course seems to need somewhat different study skills than many college courses do (even those which claim to deal with critical thinking skills...). Here are some hints that seem to work for most students.

As you'll see from the sample quiz questions, I'm almost always after a grasp of basic principles and the ability to apply them, rather than factoids. This means that, if you find yourself memorizing word-for-word definitions from the glossary or trying to put tables of numbers in your head, that's probably the wrong way to go. As an example: I will definitely not ask questions like this:

Jupiter is how many times more massive than the Earth?
a) 300 b) 318 c) 336 d) 354

but I will almost certainly ask something along the lines of

The giant planets are much more massive than terrestrial worlds because
a) their faster rotation gives them enhanced gravity.
b) they were able to retain hydrogen and helium.
c) they are made of heavier elements.
d) the Sun's gravity removed matter from the inner planets.

In approaching any completely new mass of information, we have to begin with words, since those are the gateway to communicating ideas. But don't get stuck in the gateway! The words aren't the concepts, they stand for them. Aim to grasp the concept. As an example, take the wavelength and frequency of radiation. These are ways of describing properties of the radiation, not the radiation itself. I've seen answers such as "Radio telescopes send information to astronomers by the use of frequencies". Huh? The lecture format and class size mean that it's hard to improve this in the most obvious way, by rephrasing a statement on your own and seeing whether it fits (since, if you can't put it in your own words, you don't understand it). Next best, probably, is to try this mentally and see whether it makes sense with the various statements in the textbook and lecture. And since you'd rather not do this during the lecture in case you miss something, this is a good time to mention note-taking.

Notetaking is a very important academic skill, but the best way to do that for a particular class is highly personal, so here I can only give some general guidelines. I find that the act of taking notes, of organizing your thoughts for an orderly presentation, is more important than whether you actually need to refer to them later. Imposing the structure is what makes the ideas, at least in part, your own. For example, a few years ago there was a major press conference about possible biological material from Mars. Seeing that this was the kind of thing that could be important for classes, I zipped home and flipped on CNN, notepad in hand. My thoughts in making some notes went something like this. "Meteorite. Recovered from Antarctica. Five categories of evidence: (1) Calcium carbonate regions, formed only in liquid water. (2) Magnetite crystals, on Earth always associated with bacteria. (3) Hydrocarbons with masses not usual in meteorites or interplanetary dust. (4) Iron sulfate structures, again like those left by earthly bacteria. (5) Tiny objects that look like fossil bacteria through electron microscopes, though smaller than known terrestrial counterparts." I typed this without actually needing to refer to these 2 pages of notes, because it was the process of organizing the points for my notes that helped stick the ideas into my brain.

People need different volumes, and styles, of notes, depending very much on study styles and habits. Some like a simple outline-point style, others like more completely fleshed-out sentences. For one particularly intense electromagnetism course, things went so fast that I had to keep up as best I could, then recopy the notes in a more legible form each night while I could still read the cryptic scribblings I made in the lecture.

One of the greatest challenges in approaching a mass of unfamiliar material is mental organization. What are the major points, and what points are there only as introduction or illustration? I provide one clue to this in the lecture outlines. These are (as you've noticed) pretty terse, a list of topics rather than an explanation. Each block is intended to be a major idea, with subsidiary points or explanation within these blocks. Again, let's use a concrete example from the lecture outline about the Moon.


Orbit about Earth: tidally locked (synchronous) rotation
Libration -> we seen in principle 59% of surface
Overall properties: 1/4 Earth's size, 1/81 Earth's mass
No sensible atmosphere (known from occultations)
Surface gravity about 1/6 Earth's
Surface features: dark maria
lighter highlands
Craters everywhere
Narrow straight or winding valleys (rilles)
Craters: impact vs. volcanic debate
Impact craters on Earth
Ages of surface regions from crater counts
Maria: basaltic lava flows
some originated in largest impact basins
interior heating of Moon --> later lava flooding
Lunar history: accretion of material
internal heating, differentiation
mare flooding, lunar vulcanism
impact cratering (strongest early on)

This shows how we start with the most general items (the Moon's orbit around the Earth, its size and mass) and work on to the more particular things - the kinds of surface features. The listings of maria and craters are themselves important enough to be expanded in their own blocks later in the outline. For craters, the most important point is their origin from impacts, which has implications for the age and history of the lunar surface, and which draws on what we can learn from impact craters here on Earth. Similarly maria have as their main focus the identification as lava flows, with the implication that the Moon's interior was at one time hot enough to flood immense amounts of lava onto the surface. Finally, notice how these main points feed into the summary block about lunar history, telling us about heating of the lunar interior, lava flooding, and impact cratering over subsequent history.

These hints are a first draft - I would be interested in hearing of other strategies that you find effective.

Updates, Oct. 2007: It's always a bit frustrating for me when I'm asked about the best ways to study for AY101, mostly because the best ways to take notes and study are so individual. In general, I would recommend using both the lectures and textbook. The textbook is particularly good with its review aids at the begining and end of chapters - key points, lists of terms, and review questions. You've paid for it, might as well use it! Watch out for minor topics that we skip in class for reasons of time. It's a big Universe and s short semester - for study purposes, if we don't cover it in class, it doesn't exist.

In the lectures, I've often thought that the act of taking notes is more important than having the notes later. Sitting there in a lecture, the only way in which your brain is actively engaged with the material may be in organizing thematerial on the fly in a way that makes sense to you for the notes.

One practical note that has come up in talking to a couple of students this year - when looking at the sets of old quizzes, either online or in the book of lecture outlines, be sure to check by topic rather than quiz number. Just what chapters are covered in which quiz may change from year to year.

Keel's Astronomy 101 Home Page | UA Astronomy
Last changes: 10/2007