What is an Annular Eclipse?

Narration: Beth Anthony


Roughly every year or two, somewhere in the world, the Sun appears for a few moments as a “ring of fire” in the sky.

This is called an annular solar eclipse.

“Annular” comes from the Latin word “annulus,” which means “ring.”

An annular solar eclipse occurs when a new Moon passes directly in front of the Sun but appears too small to cover it completely.

But why is that?

It’s because the Moon’s orbit around Earth isn’t a perfect circle but rather an ellipse, or slightly oval-shaped.

This causes the Moon to move closer to us and then farther away during its month-long orbit.

When the Moon is at its closest point, called perigee, it appears slightly larger in our sky.

When it’s farthest from us, at apogee, it appears a little smaller.

But we don’t see an annular eclipse every month.

That’s because the Moon’s orbit is also slightly tilted in relation to Earth’s orbit around the Sun. This means during most months the Moon is either too high or too low to block the Sun.

So only when a new Moon is at apogee and passes directly between Earth and the Sun, do spectators on Earth get the rare opportunity to see the “ring of fire” in the sky.

Unlike a total solar eclipse, when the Moon completely covers the Sun, during an annular eclipse the Sun never fully disappears.

So, if you're lucky enough to be in the path of an annular eclipse, make sure to wear your solar eclipse glasses or use other safe solar filters to witness this spectacular "ring of fire" in the sky.