WASHINGTON -- NASA will host a media teleconference at 1 p.m. EDT on Wednesday, Oct. 1, to preview the Oct. 6 flyby of Mercury by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging, or MESSENGER, spacecraft.

This second of three planned flybys will photograph most of the planet's remaining unseen surface. The spacecraft will pass 125 miles above Mercury's cratered surface, taking more than 1,200 pictures and collecting a variety of data. The flyby also will provide a critical gravity assist needed for the probe to become, in March 2011, the first spacecraft to orbit Mercury.

Briefing participants are:

- Marilyn M. Lindstrom, program scientist, NASA Headquarters in Washington

- Daniel J. O'Shaughnessy, lead for guidance and control subsystem, Johns Hopkins University Applied Physics Laboratory in Laurel, Md.

- Scott L. Murchie, co-investigator, Johns Hopkins University Applied Physics Laboratory

- Sean C. Solomon, principal investigator, Carnegie Institution of Washington

To participate in the teleconference, reporters in the United States should call 1-888-398-6118 and use the pass code Mercury. International reporters should call 1-312-470-7417.

Audio of the teleconference will be streamed live at: http://www.nasa.gov/newsaudio

Related images for the briefing will be available at: http://messenger.jhuapl.edu/news_room/index.html