MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
FOR IMMEDIATE RELEASE
November 15, 1999
WATCH RARE PASSAGE OF MERCURY BEFORE THE SUN ON WEB TODAY
Today, a rare astronomical phenomenon occurs when Mercury
passes directly between the Earth and the Sun for the final time
this century. This particular Mercury transit will be of a
particular type that has not occurred since the invention of the
telescope, and is not expected again at least through the 23rd
An important reminder -- do not attempt to view the Mercury
transit with the naked eye or with a telescope or binoculars. The
Sun can cause severe eye damage and even blindness. Telescope
images of the event from JPL will be fed live on the Internet at
http://www.jpl.nasa.gov/mercurytransit today between about 1 to
2:15 p.m. Pacific time (4 to 5:15 Eastern).
Mercury will graze just inside the Sun's disk for less than
an hour between 1:11 p.m. and 2:10 p.m. as seen from Los Angeles.
Mercury, the planet closest to the Sun, passes Earth every
116 days. But because Mercury's orbit is tilted seven degrees
relative to Earth's orbit, only about one in 23 of Mercury's
passages between the Sun and Earth results in a transit. The
most recent Mercury transits occurred in 1970, 1973, 1986 and
1993, but they were not visible in Los Angeles. After the
November 15 transit, the next one visible from Los Angeles will
take place on November 8, 2006.
NASA's Telescopes in Education project, managed by JPL, is
sponsoring telescope coverage of the event. JPL is managed for
NASA by the California Institute of Technology, Pasadena, Calif.