Don't forget to look up tomorrow. A partial solar eclipse will be visible throughout most parts of North America around 2:00 p.m. PST.

A partial eclipse like this occurs when the moon passes between the Earth and sun. This means that we still see the sun, but it looks as if the moon is taking a bite out of it. However, as the light won't change, if you forget to look for it, you won't notice anything out of the ordinary.

Most North Americans will see the event, but those in the most northern parts of the continent, will miss it, because the sun will set before the eclipse begins. The best viewing spot is in the Northwest, because the sun will still be fairly high in the sky when it starts.

The eclipse will last about two hours and, depending on where you are in North America, you'll see anywhere from 40 to 65 percent of the sun covered by the moon.

If you do plan on witnessing the event, please note that you should not look at the sun with the naked eye. Viewing the sun without protecting your eyes puts you in danger of permanent eye damage and even blindness. Even with protection, NASA recommends that you do not stare continuously at the sun.

"Take breaks and give your eyes a rest," the agency advises. "And, remember, don't use regular sunglasses— they don't offer your eyes sufficient protection."

The best and safest way to watch the eclipse is by making a pinhole projector. You can create this by putting a small hole in a card and holding it between the sun and a white screen a few feet away. This will project an image of the sun on the screen and allow you to safely watch the eclipse. You can also buy special filters for viewing, including those for your telescope. However, NASA stresses the importance of only using filters approved for solar viewing.

The easiest way for viewing the eclipse is online. You can watch the full event via Slooh.com tomorrow at 5 p.m. EST.

This is the third eclipse visible in North America this year, the other two being lunar eclipses.

If partial eclipses don't excite you, there's just three short years left until the next total eclipse of the sun is visible in the U.S. on Aug. 21, 2017.