The Micro Moon: The Full Moon Nobody Talks About

Everyone loses their mind over a supermoon.

The headlines write themselves, social media fills up with enormous orange disks, and for a few nights the Moon gets more attention than it usually does all year. Fair enough. I love me a good supermoon, too.

But there’s a quieter counterpart that almost nobody talks about, and in some ways it’s the more interesting event to understand because it completes the whole lunar picture.

The micro moon.

This is the full moon at its smallest and most distant. It tells you something fundamental about the Moon’s orbit, about gravity, about tides, and about how much our perception of the sky is shaped by comparison rather than any fixed reality.

What Is a Micro Moon?

The Moon doesn’t orbit Earth in a perfect circle. Its orbit is an ellipse, which means there’s one point in each orbit where it’s closest to us — called perigee — and one point where it’s farthest — called apogee.

When a full moon coincides with the Moon being near apogee, you get a micro moon. When it coincides with perigee, you get what’s popularly called a supermoon.

The difference in distance is significant. The Moon’s average distance from Earth is about 384,400 kilometres (238,855 miles). At perigee, it can come as close as roughly 356,500 km (221,520 miles). At apogee, it recedes to about 406,700 km (252,710 miles).

That’s a swing of roughly 50,000 kilometres (31,000 miles) between the Moon’s closest and farthest points — a difference large enough to measurably affect the Moon’s apparent size, brightness, and tidal influence on Earth.

Micro Moon vs. Average Full Moon vs. Supermoon

Let’s put some actual numbers to this.

Compared to a supermoon, a micro moon appears roughly 12 to 14% smaller in angular diameter.

That might not sound like much, but put a supermoon and a micro moon side by side in a photograph and the difference is striking — the supermoon’s disk is about 30% larger in area than the micro moon’s.

In terms of brightness, a supermoon delivers around 30% more light than a micromoon, which is a meaningful difference if you’re out observing.

To make it concrete: a micro moon has an apparent diameter of around 29.4 arcminutes. An average full moon is about 31.1 arcminutes. A supermoon can reach 33.5 arcminutes or more.

None of these differences are dramatic to a casual glance at the sky. For the most part, the Moon is the Moon.

The honest truth is that without a direct comparison, most people cannot reliably tell a micro moon from an average full moon just by looking. Our eyes are remarkably bad at judging absolute angular size in an open sky with no reference points.

What we can perceive is relative brightness, and on a micro moon night the sky does feel subtly darker, particularly if you’re familiar with how a supermoon floods a landscape.

What About the Tides?

This is the effect most people never think about, and it’s one of the most tangible differences between a micro moon and a supermoon.

The Moon’s gravitational pull drives our ocean tides. The closer the Moon is, the stronger the pull, and the higher the difference between high and low tide — called the tidal range.

A supermoon, being significantly closer than average, produces noticeably higher high tides and lower low tides, sometimes enough to cause minor coastal flooding in low-lying areas.

A micro moon does the opposite.

At apogee, the Moon’s gravitational influence is at its weakest, and tidal ranges are reduced accordingly. The difference in tidal force between a supermoon and a micro moon is roughly 20 to 25%. That’s not negligible if you’re a sailor, a coastal engineer, or someone who simply notices when the tide doesn’t come up as far as usual.

The Sun also plays a role here. When the Sun and Moon align (at full and new moons), their tidal forces combine to produce spring tides regardless of the Moon’s distance. But a micro moon full moon produces a measurably weaker spring tide than a supermoon full moon — the orbital geometry tempers what the alignment would otherwise deliver.

How Often Does a Micro Moon Happen?

The Moon completes an orbit in about 27.3 days, but because Earth is also moving around the Sun, the time from one full moon to the next — called a synodic month — is about 29.5 days.

The cycle from one apogee to the next runs on a slightly different rhythm. This means the full moon and apogee don’t line up every month — their alignments drift and drift until they converge again.

A true micro moon, where the full moon falls very close to apogee, happens roughly 1 to 3x per year, though there can be near-misses in adjacent months. Some years produce a particularly distant micro moon depending on the exact geometry; the orbit itself isn’t static and shifts gradually over time due to gravitational influences from the Sun and other bodies.

The next time you’re tracking lunar events on a calendar, you’ll notice micro moons listed far less frequently than supermoons, partly because nobody is writing breathless news articles about them.

Why the Micro Moon Deserves More Credit

The micro moon won’t make the news. It won’t look spectacular in a smartphone photo. Nobody is going to gather on the beach to watch it rise.

But it’s still beautiful, just in a quiet, underappreciated way. It doesn’t wash out the night sky as much, it doesn’t drag the tides as hard, it just comes around and does its thing. A full moon at its most modest.

But it gives us the complete story of the moon along with just a little more sky.

Get Started in Astronomy

If this has you fired up to get out under a dark sky, the next step is making sure you have the right telescope to bring with you. Not sure where to start? I put together a free PDF telescope cheat sheet that breaks down exactly which scope might be right for you, the specs that actually matter, and how to figure out your budget. Grab it — it’ll save you a lot of second-guessing before your first real dark sky night.