The 300-mile-long long channel cutting across craters on Mercury in this image from MESSENGER was first identified in October of 2008, giving scientists clues to a geologic history found nowhere else in our solar system. Deep cracks like this, found all over the planet, are thought to be caused by the contraction of Mercury as its hot interior cooled down. We will know more about the processes that created the scarps once MESSENGER establishes orbit around Mercury in March of next year and begins its dedicated, long-term mapping of the planet’s features.

Read more on the MESSENGER mission site here.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011.