Beyond the boundaries of the Earth’s atmosphere exists a nearly perfect vacuum known as “outer space.” Without gravity, with very little matter, and effectively no friction, it is an infinite void, punctuated by galaxies of stars and planets.

Our galaxy – the Milky Way – and our solar system – consisting of eight planets (excluding Pluto) circling the star known as the Sun – have been the focus of much interest, exploration, and discovery for thousands of years. Long ago, those interested in studying outer space could only look up into the sky using the naked eye to make observations. In the past 400 years, with the development of telescopes and cataloging of planets and stars, understanding of outer space has multiplied. And in the last 60 years, with the advent of physical space exploration by humans and data-collecting robots, we have encountered a mass of information regarding the moon, stars, planets, and our universe.

This collection of articles from current and past issues of The World & I provides a glimpse into the history of astronomical discovery and space exploration, and a basis for understanding the current pool of scientific knowledge. Current discoveries are featured as well, providing an intriguing starting point for discussions of future astronomical study.

Please note that articles in the field of astronomy tend to be time-sensitive, but that all of the articles in this collection have been determined to contain large amounts of useful and accurate information. However, you may find that portions of some older articles no longer represent the current understanding within the field.