On what planet was a large rectangular outcrop that is composed mainly of sandstone first observed by an English astronomer born 1618?
Horrocks Block Horrocks Block ( ) is a large rectangular outcrop that is composed mainly of sandstone, lying on the north side of Venus Glacier, 2 nmi southwest of the Keystone Cliffs, on the east side of Alexander Island, Antarctica. It was mapped by the Directorate of Overseas Surveys from satellite imagery supplied by the U.S. National Aeronautics and Space Administration in cooperation with the U.S. Geological Survey, and was named by the UK Antarctic Place-Names Committee from association with Venus Glacier after Jeremiah Horrocks, the British astronomer who predicted and first observed a transit of Venus, in 1639.
Martian soil Martian soil is the fine regolith found on the surface of Mars. Its properties can differ significantly from those of terrestrial soil. The term Martian soil typically refers to the finer fraction of regolith. On Earth, the term "soil" usually includes organic content. In contrast, planetary scientists adopt a functional definition of soil to distinguish it from rocks. Rocks generally refer to 10 cm scale and larger materials (e.g., fragments, breccia, and exposed outcrops) with high thermal inertia, with areal fractions consistent with the Viking Infrared Thermal Mapper (IRTM) data, and immobile under current aeolian conditions. Consequently, rocks classify as grains exceeding the size of cobbles on the Wentworth scale.