WASHINGTON — NASA will commemorate a quarter-century of comet discoveries and discuss upcoming comet encounters during a symposium at 9 a.m. EDT on Friday, Sept. 10, in the Knight Studio of the Newseum.

The Newseum is located at 555 Pennsylvania Ave. NW in Washington. The event will be covered live by NASA Television and streamed on the agency’s website.

Comets are remainders of material formed in the coldest part of our solar system. Impacts from comets played a major role in the Earth’s evolution, primarily during its early history billions of years ago. Some believe comets brought water and a variety of organic molecules to Earth.

The symposium participants are:

— James Green, director, Planetary Science Division, NASA Headquarters, Washington
— Anita Cochran, assistant director, McDonald Observatory, University of Texas
— Robert Farquhar, executive for space exploration, KinetX, Inc., Tempe, Ariz.
— Mike A’Hearn, principal investigator for an upcoming NASA comet encounter mission, University of Maryland
— Joe Veverka, principal investigator for upcoming NASA comet encounter mission, Cornell University

For more information about NASA TV downlinks and streaming video, visit: http://www.nasa.gov/ntv