What Is a Supermoon? (And Is It Worth Looking At)

A supermoon gets a lot of hype. The short version: it is a full moon that happens to be at its closest point to Earth, so it looks slightly bigger and brighter than usual. Nice to see, but not as dramatic as the name sounds.

Why the moon's distance changes

The moon's orbit around Earth is not a perfect circle. It is a slightly stretched oval, so the moon is a bit closer to us on one side and a bit farther on the other. The close point is called perigee. When a full moon lines up with perigee, you get a supermoon.

How much bigger is it, honestly

A supermoon is about 7 percent bigger and up to 15 percent brighter than an average full moon. That sounds like a lot, but side by side with a normal full moon your eye can barely tell. You will not look up and gasp. It is a subtle thing, best appreciated knowing what you are seeing.

The best way to enjoy one

• Catch it rising. A supermoon low on the horizon, combined with the moon illusion, is the most impressive view by far.
• Pick an open view east. You want a clear line to where the moon comes up around sunset.
• Bring nothing special. No gear needed. Your eyes are fine.

What about a "micromoon"?

The opposite also exists. A full moon at the far point of the orbit is sometimes called a micromoon, a little smaller and dimmer. Almost nobody notices.

Check tonight's phase and the next full moon on moontrack.