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 solar 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.