New images of Mars' Phoenix Lake region show where complex fault lines along a vast Martian plain have resulted in terrain with contrasting light and dark appearances.
The Phoenix Lake region, formally called Phoenicis Lacus, was first spotted by 19th century astronomers, who identified it as a dark spot that resembled a sea. Scientists now know that it is not a body of water, but the southwestern extension of the maze-like Noctis Labyrinthus system of deep valleys.
Phoenicis Lacus has an area of 3,127 square miles (8,100 square kilometers), which is roughly equal to the size of the island of Corsica in the Mediterranean Sea. Only a small portion of the region is visible in the new images, which were obtained with the High-Resolution Stereo Camera on the European Space Agency's Mars Express spacecraft in orbit around the Red Planet. [Image of Phoenicis Lacus]
Phoenicis Lacus was formed by the uplifted terrain of Mars' enormous and volcano-rich Tharsis plateau. The episodes of continuous volcanic activity in the Tharsis region not only lifted the entire plateau, but also deformed Phoenicis Lacus, creating multiple fault lines. Geological stress also carved cliffs and valleys into the landscape over time.
ESA's Mars Express launched on June 3, 2003, and arrived at Mars in December of the same year. The primary objectives of the Mars Express orbiter are to image the entire surface of Mars at high resolution, produce a map of the mineral composition of the planet's surface, and to determine the effect of the Martian atmosphere on the surface.
