The Grand Canyon … of Mars

marsglobe_viking_960This picture was stitched together from over 100 images taken by the Viking Orbiters back in the ’70s. It shows the largest canyon in the Solar System cutting a wide swath across the face of Mars. Valles Marineris is over 3,000 km long, is as much as 600 km across, and is as much as 8 km deep. The Earth’s Grand Canyon is 800 km long, 30 km wide, and not quite 2 km deep. The origin of the Valles Marineris remains a mystery, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled.

Image Credit: USGS / NASA

To Be or Not To Be Among the Fairies

What is Hamlet doing hanging out with Oberon from A Midsummer Night’s Dream?

Since 1919, the International Astronomical Union has been charged with the task of establishing “conventional” nomenclature for planets, satellites, and surface features. Namesakes from Shakespearean works have been chosen for moons and objects around Uranus. Thus, Oberon, king of the fairies, is also Uranus’ most distant and second largest moon, and Hamlet is a tragically large and princely crater on its surface, the large dark crater to the right of center. This picture shows the known surface features of Oberon. It was constructed by the U.S. Geological Survey based on data from NASA’s Voyager 2.

Image Credit: NASA/USGS