An orange disk just above the horizon? It may be the rising Moon

4 min read

A large, orange-red light glows low in the sky, partly hidden by clouds and oddly shaped: often what you’re seeing is the rising or setting Moon. Just before Christmas, the full Moon will come up in the northeast looking exactly like this. Here is how to recognize it.

What do you see?

A large orange or reddish disk just above the horizon, behind houses, trees or a hill. Often it isn't even a full circle: clouds cover part of it, or it looks flattened. It barely moves, and it seems much bigger than you would expect a celestial body to be.

According to the UK organization UAPReporting, the Moon, especially when full, is a surprisingly common source of unidentified sightings. Near the horizon it can take on strange shapes and a deep orange color.

Known cases

In 2007, a caller in South Wales phoned the emergency line to report a "bright stationary object" above a mountain that had been there for at least half an hour. The officer sent out radioed back that it was the Moon.

In July 2026, a UFO report also came in from Janesville, Wisconsin. The responding police officer identified the light as the Moon. According to a spokesperson for the 911 communications center, it was the Moon with an orange tint.

Why is it orange?

As NASA explains, the lower the Sun sits in the sky, the thicker the layer of air its light must cross to reach you. Along the way, much of the blue light is scattered, while the reds and yellows pass through. The same is true for the Moon: near the horizon it looks more yellow or orange than when it is high overhead. Dust and pollution can deepen the reddish color.

Why does it look so big?

This is the Moon illusion. Photographs show that the Moon is just as wide near the horizon as it is high in the sky, yet our eyes see it as much larger. According to NASA, we still don't know for sure why. One explanation is the Ponzo illusion: trees, houses and mountains may fool the brain when it judges distance and size. But astronauts see the Moon illusion too, even though they have no foreground.

There is one real change. According to NASA, the Moon can look slightly squashed vertically near the horizon, because the atmosphere acts like a weak lens. That is why a rising Moon can look egg-shaped or angular.

Celestial objects can also seem to "follow" a car. Because the Moon is so far away, it doesn't fall behind as you drive the way nearby trees and houses do.

When should you expect it?

December's full Moon falls on December 24 at 2:28 a.m. Budapest time. It will look full from December 23 to 25. According to BBC Sky at Night Magazine, it will be one of the biggest and brightest full Moons of the year, a so-called supermoon.

In winter, the full Moon rises in the northeast at sunset and sets in the northwest at dawn. December's full Moon follows the highest arc of the year, so it sits low only shortly after rising and before setting. That is when it looks orange and large; afterward it climbs higher and turns white.

How to check it yourself

Check where the Moon is. A sky-map app or a moonrise table shows when and where it rises that evening.
Cover it with your fingernail. At arm's length, your index fingernail is about the same size as the Moon. If the light is the same size too, it fits the Moon.
Take a photo. On your phone screen, the Moon will look much smaller relative to its surroundings than it did to your eyes.
Wait a little. If it is the Moon, it will climb higher, lose its orange color and come out from behind the clouds.

When is it not the Moon?

If the Moon is visible elsewhere in the sky at the same time, or it is new Moon, the light needs another explanation. Yellowish points of light drifting in a line may be sky lanterns, and hovering orange lights may be military flares. We cover these in separate articles.

If none of these explanations fits, note the exact time, the direction and how high the light is above the horizon, and record a video with a fixed object in the frame.

The sober take

What is certain

Near the horizon the Moon looks more yellow or orange, because its light crosses a thicker layer of air and the blue light is scattered.
The Moon illusion is a real perceptual effect: the Moon's size doesn't change in photographs, yet we see it as larger. According to NASA, we still don't know exactly why.
Near the horizon, the Moon can look slightly squashed vertically.

How to recognize it

it sits low in the northeast (after rising) or northwest (before setting);
your fingernail roughly covers it at arm's length;
it looks small in a phone photo;
over time it climbs higher and turns white.

When the question stays open

If the Moon is visible elsewhere at the same time, or isn't in the sky at all, look for another explanation. The exact time and direction can then show whether it may have been a sky lantern, a flare or an airplane.