Class Notes for Astronomy at University of Alabama

Earth's Atmosphere Earth's atmosphere is divided into four regions. The lowest of these regions is the troposphere. Here exists turbulence and atmospheric mixing due to convection currents (weather, for example). The atmos...

Properties of Earth and the Moon Out of all the planets in the solar system, Earth is the only planet that scientists can study in detail. Atmospheric scientists can measure minute by minute atmospheric conditions (weathe...

Terrestrial Planets, Gas Giant Planets The goal of planetary astronomy is to understand both the differences and the similarities (called comparative planetology) of the major objects in the solar system, includi...

Comparative Planetology: Terrestrials While each of the terrestrial planets (the Moon can be considered one of these) has its individual characteristics, many of their differences may be understood in the context of their...

Interior Structure: Core, Mantle, Crust The interior of Earth is not subject to direct investigation, but its properties must be indirectly deduced from the study of earthquake waves that propagate through the interior ro...

Other Planetary Systems The first real observational evidence that other stars might produce planets came from infrared observations coming from cool dust around stars. Study of several nearby stars, such as Vega (the...

The Age of Earth The age of Earth (and by inference, the age of most other objects in the solar system) is also not directly known. But related evidence can be studied, in this case, by the technique of radioactive dating...

Minor Objects: Asteroids, Comets, and More Four basic categories of smaller materials exist in the solar system: meteoroids; asteroids (or minor planets); comets; and dust and gas. These categories are differentiated on t...

Measurement Methods Astronomers use a variety of methods to quantify the natural phenomena that they measure. Because the physical factors that are measured in astronomy are sometimes quite large or small, astronomers use ...

Foundations of Modern Astronomy Nicolaus Copernicus and the Heliocentric hypothesis Copernicus (14731547) was a Polish scholar who postulated an alternative description of the solar system. Like the Ptolemaic geocentric (E...

Naked-Eye Astronomy Human awareness of the universe began when people realized that they could observe objects in the sky, and that what they saw changed over days, months, and years. The sky To any observer on the gro...

Introduction to the Solar System The solar system consists of the Sun, nine planets, some 60 or so moons, and assorted minor materials (asteroids, meteoroids, comets, dust, and gas). All of these objects are tiny in comp...

Electromagnetic Radiation (Light) The second great area of physics necessary to address the universe is the subject of light, or electromagnetic radiation. Visible light is the relatively narrow frequency band of electro...

Basic Physics In the sixteenth and seventeenth centuries, scientists discovered the laws of the motion of material objects. These laws help scientists to explain and predict the motions of celestial bodies. Keplers Three L...

Telescopes and Observatories The primary purpose of a telescope is to collect light over a large surface area and secondarily to produce a magnification of the image of the objects under study. The site at which one or mor...