NASA will host a media teleconference Thursday, July 3, at 2 p.m. EDT, to discuss analysis of data from the Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft's flyby of Mercury earlier this year.

The spacecraft is the first designed to orbit the planet closest to the sun. It flew past Mercury on Jan. 14, 2008, and made the first up-close measurements since Mariner 10's final flyby in 1975.

Analyses of the data show volcanoes were involved in the formation of plains. The data also suggest the planet's magnetic field is actively produced in its core. In addition, the mission has provided the first look at the chemical composition of Mercury's surface. The results will be reported in a series of 11 papers published July 4 in a special section of Science magazine.

The teleconference participants are:

• Marilyn Lindstrom, program scientist, NASA Headquarters
• Sean Solomon, principal investigator, Carnegie Institution of Washington
• James W. Head III, professor of geological sciences, Brown University, Providence, R.I.
• William McClintock, senior research associate, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder
• Thomas H. Zurbuchen, associate professor, Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor