The Equal Night
Today, September 21st, the Sun crosses the celestial equator heading south
at 0951 UT. Known as the equinox, the astronomical event marks the first
day of autumn in the northern hemisphere and spring in the south. Equinox
means equal night and with the Sun on the celestial equator, Earth
dwellers will experience nearly 12 hours of daylight and 12 hours of
darkness. Of course, for those in the south, the days will grow
longer with the Sun marching higher in the sky as summer approaches.
A few weeks after the September Equinox of 1994, the Crew of the
shuttle orbiter Endeavor recorded this image of the Sun poised above
the Earth's limb. Glare illuminates Endeavor's vertical tail (pointing
toward the Earth) along with radar equipment in the payload bay.