Earth at Perihelion Earth at Perihelion On January 4, 2001, our
planet made its annual closest approach to the Sun. January 4,
2001 -- This morning at 5 o'clock Eastern Standard time (0900
UT) Earth made its annual closest approach to the Sun -- an
event astronomers call perihelion. Northerners shouldn't expect
any relief from the cold, however. Although sunlight falling on
Earth will be slightly more intense today than it is in July,
winter will continue unabated. "Seasonal weather patterns are
shaped primarily by the 23.5-degree tilt of our planet's spin
axis, not by Earth's elliptical orbit," explains George Lebo, a
professor of astronomy at the University of Florida. "During
northern winter the north pole is tilted away from the Sun. Days
are short and that makes it cold. The fact that we're a little
closer to the Sun in January doesn't make much difference. It's
still chilly -- even here in Florida!" Right: Duane Hilton
created this view of the perihelion Sun shining down on a snowy
scene in central Cali