Mercury shows its dark side During the morning of 7 May 2003,
the planet Mercury will slip across the face of the Sun in a
rare event, known as a transit. There are only about 12
celestial alignments like this every century and you cannot view
them safely without special telescopic equipment. So, let the
ESA/NASA solar watchdog, SOHO, do all the hard work for you...
About 160 times smaller than the apparent diameter of the Sun,
Mercury will appear as a tiny dot, silhouetted on the bright
face of the Sun, as it makes its five and a half hour journey on
7 May 2003. The show will begin at 9:50 CET (7:50 UT) and last
into the afternoon, finishing at 15:17 CET (13:17 UT). Images of
the event will appear on the SOHO web site as soon as possible,
during that day. Mercury is already visible in the LASCO C3
images on 2 May 2003, edging closer to the Sun. The planets
Mercury and Venus have orbits closer to the Sun than the Earth.
They are therefore the only planets that can pass in front of
the Sun, as seen from Earth.