Happy 340th, Mars' South Polar Cap!

The above image shows three sketches of Mars made by Christiaan Huygens in 1659. Image Credit: International Planetary Cartography Database

With respect to the work of Galileo Galilei and Francisco Fontana, it is arguable that Dutch astronomer Christiaan Huygens (1629-1695) was the first observer to make a serious telescopic study of Mars. He began in 1659 and his first informative sketch of the planet was done over a number of weeks. The sketch showed a triangular feature which is still recognizable today as Syrtis Major. Huygens' results were so reliable that he used the regular reappearance of this feature to measure the rotational period of Mars. His resulting time was 24 hours, about 39 minutes short of the value recognized today.

On August 13, 1672, Huygens was able to crudely sketch the southern pole of the planet. Although he did not identify it as such at the time, Huygens recorded the feature which we recognize today as the Martian south polar ice cap.

To learn more about NASA's ongoing Mars Exploration Program, visit www.nasa.gov/mars and mars.jpl.nasa.gov .

To learn more about the latest mission to land on Mars, NASA's Mars Science Laboratory / Curiosity rover mission, visit www.nasa.gov/msl and mars.jpl.nasa.gov/msl . You can follow the mission on Facebook at: www.facebook.com/marscuriosity and on Twitter at: www.twitter.com/marscuriosity .

-