Perihelion
Perihelion is the point in the orbit of a planet or other celestial body where it is closest to the Sun. For Earth, perihelion occurs annually in early January, when the planet is about 147 million kilometers (91 million miles) from the Sun.
Source: ssd.jpl.nasa.gov
APODs including "Perihelion"
Tails Of Comet LINEAR
27/07/2000
Comet C/1999 S4 LINEAR is only one of many comets discovered with the Lincoln Near Earth Asteroid Research (LINEAR) telescope operating near Soccoro, New Mexico, USA. Traveling steadily southward through Earth's night sky, C/1999 S4 passed perihelion (closest approach to the Sun) yesterday on what is likely its first trip through the inner solar system. Now fading, comet LINEAR became no brighter than about 6th magnitude, but is still easily visible with binoculars in northern hemisphere skies. While the memorable comets Hale-Bopp and Hyakutake were much brighter, comet LINEAR is displaying delightful tails evident in this false-color composite image from the Crni Vrh Observatory in Slovenia. The combined series of exposures made on July 22nd are registered on the comet. In the resulting picture, stars appear as rows of dots, but the faint structures in the comet's tail are beautifully recorded. Presently seen moving from Ursa Major to Leo this comet LINEAR will begin to shine in southern hemisphere skies in August.