Solar Eclipse 101
On February 26, lucky sky-watchers across South America and Africa will witness the sun turn into a dramatic ring of fire due to an event known as an annular eclipse.
A solar eclipse occurs when Earth, the moon, and the sun line up perfectly so that the moon casts a shadow on our planet. However, the moon follows an elliptical orbit around Earth, and over time the distance between the two objects can vary. For sky-watchers, that means the apparent size of the lunar disk in the sky changes, too.
A total solar eclipse happens when the moon is close enough to Earth that it seems to completely cover up the sun. Annular eclipses occur when the moon is farther from Earth and appears to be smaller than the visible disk of the sun, so it does not cover up our star completely.
This week's main event will be visible along a nearly 20-mile-wide path, which will first touch land in the southernmost portion of South America around local sunrise.
The full ring will be visible over Chile starting at 10:35 a.m. local time. The eclipse will then move quickly through the Patagonia region of Argentina before racing across the Atlantic Ocean.
The annular eclipse makes landfall again in Angola at 4:20 p.m. local time, travels over Zambia, and ends around 6:30 p.m. local time in the Democratic Republic of the Congo.
While only people along the path of totality will see the ring, much of the Southern Hemisphere will enjoy the celestial phenomenon of a partial eclipse, when the moon seems to take a bite out of the sun.
Viewers in most of Brazil, Paraguay, and Bolivia will be able to see the moon covering up to 40 percent of the sun, while folks in most of Argentina, Uruguay, and southern and equatorial Africa will see up to 90 percent covered.
Remember to never look directly at the sun without proper eye protection, even when the sun is visible as only a thin crescent during an eclipse.
If you are using a telescope or camera, you can use specially designed solar filters over the front lenses to avoid eye damage. You can also watch with special eclipse viewing glasses that sufficiently reduce the sun's brightness and filter out its harmful rays.
Eclipse fans can get indirect views of the event by building an eclipse viewer, which projects an image of the sun onto a flat surface.
If you are clouded out or can’t make it into the eclipse pathway, the robotic telescopes of astronomy outreach venture Slooh will offer a live stream of the encounter beginning at 7:00 a.m. ET on February 26.
And if you do miss this event, a much more dramatic total eclipse of the sun will occur on August 21, when the moon’s shadow will completely blot out the sun in a path that cuts right across the continental United States.