You embark on a fantastic voyage throughout the Universe, starting in this lecture with a whirlwind tour of the course, which extends from phenomena in Earth's atmosphere to events at the farthest reaches of space and time.

Many objects in the night sky can be enjoyed with the naked eye, even from the city. These include several famous constellations, bright stars, planets, and satellites such as the International Space Station.

Far from city lights, the night sky becomes spectacular and includes such sights as the Milky Way, the Magellanic Clouds, zodiacal light, and comets. Though not technically "celestial," auroras are also wondrous spectacles.

A relatively inexpensive telescope and even a simple pair of binoculars greatly increase the number of celestial objects you can study, such as the craters on the Moon, the Orion Nebula, and the Andromeda Galaxy.