Astronomy is ubiquitous in our culture. Headlines frequently include reports from NASA space probes and pretty pictures from the Hubble Space Telescope. PBS regularly features educational programs about black holes and “exoplanets.” Textbooks are full of factoids about the solar system, such as the size, distance, and composition of the Sun, the planets, and their moons.

One might get the impression that this is all there is to know about astronomy. One might believe that there is nothing more to astronomy than NASA discoveries and observations from major institutional observatories. Mainstream astronomy as presented is mostly ornamental and aesthetic. Some people find it interesting and others do not, but few find any practical value in studying this subject. One might be inclined to say “why bother?” to astronomy.

Yet many people have also heard that astronomy is the most ancient science, that the sky was studied for millennia prior to the invention of the telescope. We’ve heard that historically, astronomy was part of the quadrivium, one of the seven liberal arts. Many classical homeschoolers today have rediscovered the trivium arts: grammar, dialectic, and rhetoric. Homeschoolers of all approaches teach their children the quadrivium arts of arithmetic, geometry, and music. And yet, astronomy is usually not ranked very high in importance. For many homeschoolers, astronomy is an elective at best, and for many others it is irrelevant and non-essential.

The problem with contemporry astronomy education is an emphasis on modern astronomy, including planetology, cosmology, astrophysics, and other conclusions of professional science, handed down on authority from the science mainstream. Yet many of us stand in our backyards gazing up at the sky, wishing to understand what we are seeing, wondering if there is anything of practical value to learn from the sky above.

Discovering the Forgotten Sky

The solution to these problems is the study of classical astronomy. Our ancestors studied the sky for practical reasons. For centuries, the cycles of the Sun, Moon, and stars were used for telling time—measuring the time of day, the day of the month, and the month of the year. Historically, the sky had been observed in order to find the directions of the compass points: north, south, east, and west. Down through history, great navigators such as Columbus used the celestial signposts to discover new lands and find their way home again.

Indeed, throughout all pre-industrial history and prior to the invention of modern instruments, observation of the Sun, Moon, and stars was the only way that one could tell time or find direction. We find in Scripture that this is actually the purpose for which the celestial bodies were created: “And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years” (Genesis 1:14)

Even in our high-tech era, we can still gaze up from our backyards to learn the Biblical purposes for the celestial bodies. We can observe changes in the position of the Sun, drawing high overhead in the summer and low in the winter, causing the days to grow long and short. We can follow the monthly cycle of the Moon’s phases, and we can learn how this cycle forms the basis for the calendar of Biblical Hebrew feasts. We can identify the bright stars and track the prominent constellations as they change from season to season. We can identify the planets and follow their motions through the stars over the months and years. And we can discover how the Sun, Moon, and stars point the directions to the compass points.

In addition  to learning celestial timekeeping and navigation, we can find out how classical astronomy can provide practical instruction in applied geometry and trigonometry. We can continue to discover how classical astronomy is an important basis for classical geography, since the appearance of the sky changes with location over the globe. Knowledge of the sky can add to our appreciation of the Lord’s handiwork.  

The Rise and Fall of Classical Astronomy