An example of how geologists estimate the thickness of lava flow deposits on Mercury. (Left) A fresh impact crater (Hokusai, 114 km diameter, 57.8° N, 343.1° E) provides the opportunity to measure the depth of its interior and the height of its rim above the surrounding terrain. (Right) A "ghost" crater (90 km diameter, 74.3° N, 335.7° E), a circular feature in the volcanic plains outlined by ridges, suggests that the outpouring of the volcanic plains have buried a preexisting impact crater. From an estimate of the height of the rim of the buried crater, the thickness of the lava covering the crater may be determined.

The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MDIS is scheduled to acquire more than 75,000 images in support of MESSENGER's science goals.

Date Presented: September 29, 2011, at a NASA Press Briefing
Instrument: Mercury Dual Imaging System (MDIS)

These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy.