Stretching from Mexico into the United States and Canada, the moon will completely blot out the sun.

Here's what you need to know about it.

In a total solar eclipse, the moon passes between the sun and Earth.

That covers the face of the sun along a small path of our planet's surface, called the "path of totality."

The daytime sky turns dark as a result.

In places along the path of totality, people will be able to view the sun's corona - the star's outer atmosphere - which is typically not visible because of solar brightness.

People observing from outside the path of totality will see a partial eclipse.

But a cloudy day could spoil the view.

According to NASA, the April 8 eclipse will begin over the South Pacific.

The path will reach Mexico's Pacific coast around 11:07 a.m. Pacific Time before entering the United States in Texas.

Its path then takes it through various states, including Oklahoma, Illinois, Kentucky, New York, and Maine.

The path then enters Canada in Ontario and journeys through the eastern provinces.

It will exit on the Atlantic coast of Newfoundland at 5:16 p.m. Newfoundland Time.

A partial eclipse is due to be visible for people in all 48 contiguous U.S. states.

It is unsafe to look directly at the bright sun without using specialized eye protection.

Experts say viewing an eclipse through a camera lens, binoculars, or telescope without making use of a special-purpose solar filter can cause severe eye injury.

They advise using safe solar viewing glasses or a safe handheld solar viewer...

and note that regular sunglasses are not safe for viewing the sun.

The only moment it is considered safe for people to remove eye protection during a total solar eclipse is the brief

time when the moon completely blocks the sun's surface.

After this one, the next total solar eclipse viewable from the contiguous United States will not occur until 2044.