Today, kids studying astronomy and the solar system benefit from modern technology, sophisticated telescopes, affordable solar astronomy tools, and centuries of observation to better understand the relationship between the entire solar system, the sun, and the earth.
But hundreds of years ago, there were only a few scientists who were bold enough to challenge the accepted theories of the solar system. Let’s take a look at three of the most important early solar astronomers –– Copernicus, Brahe, and Kepler –– and understand their contributions to our study of the stars!
Nicolaus Copernicus was a Prussian mathematician who lived during the Renaissance, from 1473-1543. Copernicus was one of the first astronomers to argue that the Earth revolved around the Sun –– and not the other way around! This heliocentric theory of the universe was extremely controversial at the time, especially because it threatened commonly accepted religious views that God had placed the Earth at the center of the universe.
Copernicus developed his theory using extensive sets of astronomical tables and scientific proofs, and built his theory on earlier theories proposed by Plato, Aristarchus of Samos, and the Pythagoreans. One of the most important clues was the movement of Venus and Mercury in relation to the Sun; astronomers of the time observed that these planets moved as if “tethered” to the Sun, with some movement ‘forwards’ and ‘backwards’ over time. This sparked the idea that it was the Sun, not the Earth, which controlled the movement of the planets in the solar system –– including our own.
Copernicus developed his ideas for decades, even working on his book in which he planned to publish them up until the day he died –– literally! It is rumored that, when Copernicus became ill in 1543, he eventually slipped into a coma, only to wake up and review the final pages of his book one last time before passing away. That book, De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres), was not exactly an astronomy book about the solar system written for kids, but it did eventually change the way future generations thought about the relationship between the Earth and the Sun. This fundamental shift in thinking is known as the Copernican Revolution!
While Nicolaus Copernicus devised his heliocentric theory based on existing studies of the solar system, most of his contribution to our understanding of astronomy was through re-examining that data.
Tycho Brahe, a Danish astronomer and contemporary of Copernicus, left his mark on the field of astronomy by conducting thousands of observations, studies, and experiments of his own. Brahe believed that more careful observations could lead to better data, and better data could lead to more accurate models of the solar system.
Among Brahe’s most significant breakthroughs was his observation and measurement of a new star within the Cassiopeia constellation. In 1572, Brahe was studying the constellation when he thought he noticed a new star –– a hunch he confirmed by using a measurement tool called a sextant. What was so extraordinary was that, at the time, it was believed that the realm of the stars was “perfect,” unable to be changed.
Brahe’s new belief that, in fact, new stars could appear within the celestial realm was validated with the appearance of a comet in 1577. Brahe tracked the movement of the comet and determined that it was soaring through the “spheres” of various planets and the Moon.
Brahe used these observations, and others, to develop his new model for the solar system. The Tycho Brahe solar system model suggested that all of the planets revolved around the Sun… but that the Sun and the Moon (and therefore all of the planets, as well) orbited the Earth. In other words, according to Brahe, the Earth was still the center of the universe, but the rest of the planets revolved around the Sun.
The fact that Brahe still believed the Earth to be at the center of the universe has opened him up to some retrospective scrutiny; some scientists say it was a step backwards for astronomy. However, other scientists appreciate that Brahe was accounting for something called ‘stellar parallax’. This is the phenomenon of the stars in the sky maintaining their position despite the Earth moving around the Sun and not the other way around. While it is true that Brahe wasn’t exactly correct in his theory of the solar system, he at least proposed another way of looking at it –– and at the time, that in and of itself was revolutionary thinking.
Johannes Kepler was a student of Brahe who became a famous astronomer in his own right. Kepler combined elements of astronomy, mathematics, science, and astrology. According to Kepler, Tycho Brahe’s solar system theories didn’t go far enough in accounting for what he saw as a harmony which connected all things in the universe. For Kepler, geometry and physics were just as important as astrology and mysticism.
In 1609, Kepler published Astronomie Nova, in which he laid out his observations of Mars and its orbital shape. This is one of the first accounts of an oblong planetary orbit versus a perfectly circular orbit. In addition to changing the thinking of how planets moved –– elliptical rather than circular –– Kepler also offered one of the first instances of a theory that a force of attraction helped organize celestial bodies. This work laid the groundwork for what would become a fundamental theory of physics and something that all kids studying astronomy and the solar system have heard of: gravity!
Continue Your Study of the Stars
Rainbow Symphony wants to encourage the next generation of famous solar astronomers! If you’re a kid interested in astronomy and the solar system, explore our collection of eclipse gear, diffraction glasses, and other educational tools designed to help you make discoveries of your own.
Who knows? You may even challenge some astronomical theories of your own!