Astronomy is the oldest of sciences. Yet it remains as important today as when humans first began to understand the motions of the Sun, Moon, planets and stars. We live at a crucial phase in the history of our planet. For the first time in history, we have the power to affect, for better or worse, the nature of our planet. Modern planetary astronomy provides us with a glimpse of the diversity of other worlds, from the runaway greenhouse effect on Venus and the changing climate of Mars to the shifting ice flows on the moons of Jupiter and Saturn.
Astronomy places human development in context.
The planets in our solar system began to form about 5 billion years ago as a result of violent collisions between chunks of debris left over from the formation of the Sun. This time period is more than 500 times farther back in prehistory than the appearance of the first human-like beings on Earth. Although astronomy cannot hope to solve our problems on Earth, it can provide us with a perspective of our surroundings which may positively influence future decisions we make about our fragile world, and the millions of life forms that exist on its surface and in its oceans. Perhaps the best reason to study astronomy is the simple beauty of a dark night sky. We hope to try to capture some of the spirit of this statement in Astro 120.