Space Science after Galileo

Galileo’s observations of sunspots proved the corruptibility of the heavens. He persuaded others of this argument by employing the most appropriate data visualization technology of the day:  a long sequence of full-page copper-plate engravings of the solar disk. Detailed visual representations now became essential to space science.

In the late 20th century, spaceships and space probes began to reach the Moon and other planets of the solar system. Some of these voyagers from Earth carried the names of space scientists after Galileo. Cassini and Huygens, architects of planetary science, provided the first sketches of Mars, Jupiter and Saturn. Others investigated the Earth in relation to the cosmos, discerned additional planetary satellites, and discovered unexpected solar system objects unknown to the ancients.

Newton integrated Galileo’s terrestrial physics and Kepler’s laws of the heavens into a universal theory of gravitation, prompting new reflections on the nature of the universe itself. The example of “nebulae” illustrates these changes. “Nebulae” at one time meant “clouds” to Latin meteorologists, yet came to refer to misty clouds in the heavens revealed by telescopes but not easily resolved. Ultimately, many nebulae came to be understood as new galaxies in deep space, constantly receding in every direction from our own Milky Way. Developments like these might seem to vindicate Copernicus who exclaimed, “So vast, without any question, is the divine handiwork of the most excellent Almighty,” in one of the sentences censored by the Inquisition in 1616. 

Galileo discovered more than 100 unsuspected stars when he turned his telescope toward Orion and Taurus. Ever since, the number of known stars has continued to increase. Similarly, Ptolemy described 48 constellations in the Almagest; currently there are 88. Galileo inscribed the OU copy of the Starry Messenger to a poet. The human experience of the night sky has always combined scientific and imaginative aspects. Art, literature and astronomy merge in a creative and ongoing exploration of the stars and constellations.