NEW YORK — Two bright green comets are streaming through the skies and are visible to skygazers in the Northern Hemisphere.

Both hail from the outer edges of our solar system — possibly what’s known as the Oort Cloud, well beyond Pluto. Comet Lemmon will have its closest brush with Earth on or around Tuesday. The other cosmic snowball, Comet SWAN, should have its flyby with Earth on Monday, but it’s headed away from the sun and will likely grow dimmer as the days pass.

Spotting two comets simultaneously without special equipment is “rare, but not unprecedented,” said Carson Fuls, director of the University of Arizona-based sky survey that spotted Comet Lemmon.

To see the pair, go outside just after sunset and look to the northern sky for Comet Lemmon close to the horizon. Comet SWAN wil

See Full Page