Douglas Isbell
Headquarters, Washington, DC                           April 27, 1999
(Phone:  202/358-1547)

Bill Steigerwald
Goddard Space Flight Center, Greenbelt, MD
(Phone:  301/286-5017)

Mary Hardin
Jet Propulsion Laboratory, Pasadena, CA
(Phone:  818/354-5011)

NOTE TO EDITORS: n99-24

BRIEFING:  MAGNETIC CRUST ON MARS A WINDOW TO THE PAST

     Surprising magnetic features on the Martian surface that suggest 
striking similarities between Earth and ancient Mars will be 
presented at NASA's next "Space Science Update" on Thursday, April 
29.  

     The program will be held at 2 p.m. EDT in the James E. Webb 
Auditorium at NASA Headquarters, 300 E St. SW, Washington, DC.  News 
coverage of this story is embargoed until 3 p.m. on April 29.

     An instrument aboard NASA's Mars Global Surveyor, now in orbit 
around the Red Planet, detected the features.  If the initial, peer-
reviewed interpretations are confirmed, the finding could 
revolutionize scientific understanding of early Mars.

     Briefing presenters will include:

     -- Moderator Dr. Carl Pilcher, science director for Solar System 
Exploration in the Office of Space Science at NASA Headquarters;
     -- Dr. Mario Acuna, principal investigator on the Mars 
Global Surveyor magnetometer/electron reflectometer instrument from 
NASA's Goddard Space Flight Center, Greenbelt, MD;
     -- Dr. Jack Connerney, co-investigator on the Global Surveyor's 
magnetometer instrument, from Goddard;
     -- Dr. Ronald Merrill, Professor of Geophysics and Geological 
Sciences at the University of Washington in Seattle, who will discuss 
the significance of the Mars results for studies of Earth; 
     -- Dr. Vicki L. Hansen, Professor of Geological Sciences at 
Southern Methodist University in Dallas, TX, who will discuss the 
implications of the findings for the overall study of Mars and the 
Solar System's other rocky planets: Mercury, Venus and Earth.

     Mars Global Surveyor carries five science instruments designed 
to generate a complete global portrait of Mars and its seasonal 
changes during a full Martian year, the equivalent of two Earth 
years.  The spacecraft arrived in orbit around Mars in September 1997 
and began full-scale mapping on March 9, 1999.

     The briefing will be carried live on NASA Television, available 
on transponder 9C of the GE-2 satellite at 85 degrees West longitude, 
vertical polarization, frequency 3880 MHz, audio of 6.8 MHz.  Two-way 
question and answer capability will be available for news media at 
NASA centers.

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