David_Aldrich's Blog

Mercury as Never Seen Before

Oct. 7, 2008: Yesterday, NASA's MESSENGER spacecraft flew past Mercury and photographed a broad swath of never-before-seen terrain. The first of more than 1,200 high-resolution images are arriving back at Earth now.

"The MESSENGER team is extremely pleased by the superb performance of the spacecraft and the payload," says MESSENGER Principal Investigator Sean Solomon of the Carnegie Institution of Washington. "We are now on the correct trajectory for eventual insertion into orbit around Mercury, and all of our instruments returned data as planned."

This spectacular image – one of the first to be returned – was snapped by the spacecraft's Wide Angle Camera (WAC) about 90 minutes after MESSENGER's closest approach to Mercury, when the spacecraft was at a distance of about 27,000 kilometers (about 17,000 miles):

Above: New photographs of Mercury's unseen side reveal a dramatic system of globe-straddling rays. [full caption]

The most striking characteristic of this newly imaged area is the large pattern of rays streaking downward from the planet's northern regions. The ray system appears to emanate from a relatively young crater previously seen in Earth-based radar images but photographed by a spacecraft for the very first time just yesterday. This view of the planet is distinctly unique from what MESSENGER saw during its first flyby in Jan. 2008.

In the mid-1970s when Mariner 10 flew past Mercury three times, the probe imaged less than half the planet. MESSENGER's first flyby in January of this year covered another 20 percent of the planet's surface. Yesterday, Oct. 6th, MESSENGER successfully completed its second flyby of Mercury, unveiling another 30 percent of Mercury's surface that had never before been seen by spacecraft.

"When these data have been digested and compared, we will have a global perspective of Mercury for the first time," notes Solomon.

Data from the flyby continue to stream down to Earth, including higher resolution close-up images of this previously unseen terrain.

Visit the MESSENGER photo gallery for updates.

Editor: Dr. Tony Phillips | Credit: Science@NASA