Page 8 - (DK) Eyewitness - Mars

Mars of the ancients

For thousands of years, astronomers had no telescopes. They had
only their eyes to observe stars and planets—the “heavenly bodies.” Ancient
scientists came to know six planets: Mercury, Venus, Earth, Mars, Jupiter,
and Saturn. Since they moved past the “fixed” stars of the night sky, the
planets earned the name “wandering stars.” Four thousand years ago, the
IN THE NIGHT SKY Egyptians called Mars—which glows orange-red—Har Décher, the “Red One.”
Mars, at right, is the
second-brightest object in Centuries later, Babylonians named it Nirgal, the “Star of Death.” By the 5th
this photograph. Jupiter is century bc, Romans had named the planet Mars, for their god of war. The
the brightest. Planets reflect
the strong light of the Sun 2nd-century ad astronomer Claudius Ptolemy believed that Mars, the Sun,
and do not twinkle like Moon, and other planets all revolved around the Earth. Ptolemy’s theory
stars, which are trillions of
miles farther away. Starlight was “geocentric”—Earth-centered. This theory ruled the thinking of
is distorted—twinkles—in
the Earth’s atmosphere. astronomers for more than 1,400 years.

THE PTOLEMAIC SYSTEM
Ptolemy’s Earth-centered concept of the Solar System is shown in this 17th-century “celestial planisphere.” Seven heavenly bodies
revolve around the Earth. From the “geo-center,” they are: the Moon, Mercury, Venus, the Sun, Mars (Martis), Jupiter, and Saturn.
Colorful planispheres were published in Europe as “celestial cartography,” or maps of the heavens.