Introduction: Planetary geosciences, the Dutch contribution to the exploration of our solar system

Abstract

Planetary geoscience was effectively born when Christiaan Huygens took his first look at planet Mars on Friday 28 November 1659. As one of the leading scientists of his time, Huygens was known for constructing his own telescopes to observe stars, planets and nebulae whenever the clear and spacious skies above the Netherlands allowed. Huygens observed the planet Mars during the heydays of its 1659 opposition. On the night of 28 November he succeeded in sketching the first albedo feature on a different planet in our solar system. The roughly triangular dark-coloured patch was originally christened the Hourglass Sea, suggesting it to be an area of open water. Perhaps the landscape surrounding him in the Netherlands prompted Huygens to interpret the newly discovered feature as a wet area on the planet's surface. The attribution of traits to an albedo feature on another planet based on terrestrial landscapes may well be considered as the first-ever attempt at ‘comparative planetology’. The albedo feature can still be recognised at the surface of Mars today as Syrtis Major. Any modest amateur telescope can provide a view superior to that of Huygens’, allowing the observation of the very first geological feature ever identified on another rocky planet.