#firmicus

[quiltofstars]

Mare Crisium (”The Sea of Crises”), Cleomedes crater (right), Condorcet crater (bottom left), and Firmicus crater (left) // Richard Delhoume

Mare Crisium, the Sea of Crises, was the site of a crash-landing of Soviet Luna 15 in 1969, and soft-landing of Luna 24 in 1976.

Cleomedes crater is named after the Greek astronomer Cleomedes (dates unknown), who wrote a textbook containing the original source for how Eratosthenes measured the Earth’s circumference to within 2%.

Firmicus crater is named after the Roman astrologer Julius Firmicus Maternus (c. 300s CE).

Condorcet crater is named after the French mathematician Marquis de Condorcet (1743-1794) who worked on calculus and also promoted the equal rights of women and all races.

[quiltofstars]

The Moon with featured craters (right to left) Petavius, Balmer, Langrenus, Apollonius, and Firmicus and seas Mare Fecunditatis (”Sea of Fertility”) and Mare Crisium (”Sea of Crises”) // Georges

Petavius crater is named after the French Jesuit Denis Pétau (1583-1652) known for his works on chronology.

Balmer crater is named after the Swiss mathematician Johann Balmer (1825-1898) who studied the hydrogen atom, discovering its series of optical emission lines.

Langrenus crater is named after the Dutch astronomer Michael van Langren (1598-1675) who used observations of the Moon to help determine longitude on Earth.

Apollonius crater is named after Apollonius of Perga (c. 240 BC - 190 BC), an ancient Greek astronomer who defined the terms ellipse, parabola, and hyperbola, and introduced eccentric orbits for the planets.

Firmicus crater is named after Julius Firmicus Maternus (c. 300s AD), a Roman astrologer.