This week marks the birthday of the late scientist and science educator Carl Sagan, born in 1934. Sagan is best remembered today for his work popularizing and communicating science, particularly with his several books and his popular television program Cosmos.

Carl Sagan stands beside a model of the Viking Mars lander (NASA photo)

Less well known these days, however, is his professional work as an astrophysicist studying planetary atmospheres. He contributed to early work establishing surface conditions on Venus, extrapolating pressure and temperature ranges from radar reflectivity data. He likewise studied atmospheric flow on Earth, Mars, Jupiter, and the trace gases of the Galilean moons.

In conjunction with his science education work, he went on to extrapolate from this and argued convincingly of the potential perils of climate change on Earth as well, as reflected in the more extreme changes on Venus.

But in the end, his most crucial contribution was as an educator and communicator of science, bringing his joy and fascination with scientific discovery to the masses, and inspiring many young people to follow his path into the sciences.


 Some of Sagan's early work:

Sagan, C. (1961). The planet Venus. Science, 133(3456), 849-858.

Sagan, C. (1962). Structure of the lower atmosphere of Venus. Icarus, 1(1-6), 151-169.

Sagan, C., & Pollack, J. B. (1967). Anisotropic nonconservative scattering and the clouds of Venus. Journal of Geophysical Research, 72(2), 469-477.

Sagan, C., & Veverka, J. (1971). The microwave spectrum of Mars: An analysis. Icarus, 14(2), 222-234.

Sagan, C., & Mullen, G. (1972). The Jupiter greenhouse. Icarus, 16(2), 397-400.

Sagan, C., & Mullen, G. (1972). Earth and Mars: Evolution of atmospheres and surface temperatures. Science, 177(4043), 52-56.

Sagan, C., Toon, O. B., & Gierasch, P. J. (1973). Climatic change on Mars. Science, 181(4104), 1045-1049.

Sagan, C. (1975). Windblown dust on Venus. Journal of the Atmospheric Sciences, 32(6), 1079-1083.

Sagan, C., & Bagnold, R. A. (1975). Fluid transport on Earth and aeolian transport on Mars. Icarus, 26(2), 209-218.

Smith, B. A., Soderblom, L. A., Johnson, T. V., Ingersoll, A. P., Collins, S. A., Shoemaker, E. M., ... & Cook, A. F. (1979). The Jupiter system through the eyes of Voyager 1. Science, 204(4396), 951-972.

SMITH, B. A., Soderblom, L. A., Beebe, R., Boyce, J., Briggs, G., Carr, M., ... & Hunt, G. E. (1979). The Galilean satellites and Jupiter: Voyager 2 imaging science results. Science, 206(4421), 927-950.

Squyres, S. W., Buratti, B., Veverka, J., & Sagan, C. (1984). Voyager photometry of Iapetus. Icarus, 59(3), 426-435.

Sagan, Carl, et al. "Polycyclic aromatic hydrocarbons in the atmospheres of Titan and Jupiter." The Astrophysical Journal 414 (1993): 399-405.