NASA will hold a media teleconference at 1 p.m. EDT, Thursday, June 28, to discuss the scientific reasoning and risks related to the Mars rover Opportunity’s planned descent into the massive “Victoria Crater.” Opportunity has been exploring layered rocks in cliffs around the Martian crater.

Briefing participants are:

— Alan Stern, NASA associate administrator, Science Mission Directorate, NASA Headquarters, Washington

— Michael Meyer, lead Mars program scientist, Science Mission Directorate, NASA Headquarters, Washington

— John Callas, Mars Exploration Rover project manager, NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

— Steve Squyres, principal investigator, Mars Exploration Rover science instruments, Cornell University, Ithaca, N.Y.

Media interested in participating in the teleconference should call 888-398-6118. International media should call 210-234-0018. The passcode is “crater.”

Live audio of the teleconference will be streamed at: http://www.nasa.gov/newsaudio

Audio replays of the teleconference will be available until July 2 by calling 866-458-4759. International media should call 203-369-1316.

Supporting images and graphics for the teleconference will be posted at: http://www.nasa.gov/rover