Have you ever looked up at the night sky and noticed that the Moon sometimes seems bigger or smaller? That’s because the Moon doesn’t travel in a perfect circle around Earth. Instead, its path is more like an oval shape, called an ellipse. This causes the Moon to get closer to Earth at some points and farther away at others. The closest point is called perigee, and the farthest is apogee. If you’re an amateur astronomer—someone who enjoys stargazing as a hobby—tracking these points can make your sky-watching more exciting. This article will explain everything you need to know in simple terms, including how to find real-time info and answer common questions.
What Are Apogee and Perigee?
Let’s start with the basics. The Moon orbits Earth every about 27.3 days. But because its orbit is elliptical, the distance between Earth and the Moon changes.
- Perigee: This is when the Moon is at its closest point to Earth. The average distance is around 363,000 kilometers (about 225,000 miles), but it can get as close as 356,000 km.
- Apogee: This is when the Moon is farthest from Earth. The average is about 405,000 km (251,000 miles), but it can reach up to 406,000 km.
These changes happen roughly every two weeks, alternating between perigee and apogee. When the Moon is at perigee and it’s full, we call it a “supermoon” because it looks up to 14% bigger and 30% brighter. At apogee during a full Moon, it’s a “micromoon,” looking smaller and dimmer.
Understanding the Moon’s Orbit
The Moon’s path around Earth isn’t a circle—it’s stretched out like an egg. Earth sits at one focus of this ellipse, so the Moon swings closer on one side (perigee) and farther on the other (apogee). Gravity from Earth pulls on the Moon, keeping it in this orbit, but the Sun’s gravity also tugs a bit, making the orbit wobble slightly over time.
The orbit tilts about 5 degrees compared to Earth’s path around the Sun, which is why we don’t get solar and lunar eclipses every month. Tracking apogee and perigee helps you predict when the Moon will look its best or affect things like ocean tides more strongly.
Why Should Amateur Astronomers Track Apogee and Perigee?
Tracking these points isn’t just for scientists—it’s fun and useful for hobbyists too!
- Better Viewing: At perigee, the Moon appears larger, making it easier to spot details like craters with binoculars or a small telescope.
- Photography: Capture amazing photos of supermoons. The size difference is noticeable if you compare shots from perigee and apogee.
- Science Fun: Notice how tides are higher during perigee (called “perigean spring tides”) because the Moon’s gravity pulls stronger on Earth’s water.
- Planning Observations: Know when the Moon is farthest so it doesn’t wash out faint stars or galaxies you’re trying to see.
- Educational Value: Share facts with friends or family during stargazing sessions.
Plus, it connects you to real astronomy. Events like supermoons get a lot of buzz, so tracking helps you join in.
Lunar Apogee and Perigee Calendar
Use the interactive widget below to generate the Moon’s apogee and perigee calendar for any year. You can view, explore, or download it as a PDF for offline reference. For deeper insight, cross-reference the results with the current phase in the Lunar Calendar to see whether each event aligns with a Full Moon or New Moon—that’s how you can easily identify upcoming supermoons and micromoons.
Enter a year, click Generate, and match the apogee or perigee dates with the Lunar Calendar below to view the Moon’s phase for each event.
[lunar_calendar]
How to Track the Moons Apogee and Perigee
You don’t need fancy equipment—just some curiosity and the widget above. Here’s how:
- Use the Built-In Calculator
The interactive calendar on this page shows all perigee and apogee dates for your chosen year. You can filter by month, view exact distances, and even download your results as a PDF.- Distances under 360,000 km indicate the Moon is near perigee (closest).
- Distances over 400,000 km indicate it’s near apogee (farthest).
- Simple Calculations
If you like math, you can estimate using Kepler’s laws, but it’s easier with the built-in tool. The time between perigees (the anomalistic month) is about 27.55 days—your calculator uses this to generate accurate predictions automatically. - Observe Yourself
Use a telescope to measure the Moon’s apparent size. Take photos monthly and compare. Tools like a micrometer eyepiece can help, but even eyeballing works for beginners. - Join Communities
Follow astronomy forums on Reddit (like r/astronomy) or apps like Bluesky for updates. Search for #Supermoon or #MoonApogee to see how others are using data like yours.
Tips for Observing as an Amateur
- Best Times: Observe during full Moon phases near perigee for supermoons. Check a Moon phase calendar.
- Equipment: Start with binoculars. A telescope with 50x magnification shows craters clearly.
- Location: Find a dark spot away from city lights. Use a star map app.
- Safety: Never look at the Sun through optics, but the Moon is safe.
- Record It: Keep a journal of dates, distances, and what you see.
- Weather Check: Use apps like Clear Outside for sky conditions.
If you’re new, join a local astronomy club—they often have events around these times.
🌓 Frequently Asked Questions (FAQ)
How do I find the Moon’s current distance?
You can use the interactive Moon Distance Tracker in the widget above, or search “Moon distance today” to compare live data with other sources.
Is there a supermoon soon?
Check the Apogee & Perigee Calendar above. If the Full Moon aligns with a perigee date, that’s a supermoon!
For example, the November 5, 2025 perigee is close to the Full Moon on November 6—yes, that’s a supermoon!
Why does the Moon wobble?
It’s called libration, which allows us to see about 59% of the Moon’s surface over time.
Learn more about the Moon’s wobble →
Does apogee affect eclipses?
Yes. When a solar eclipse happens at apogee, the Moon appears smaller and may produce an annular (ring-shaped) eclipse instead of a total one.
Can I calculate it myself?
You could use orbital math (the Moon travels about 1 km per second), but it’s much easier with the built-in calculator widget above.
What if I miss one?
Don’t worry—apogee and perigee events happen every month, so there’s always another chance.
Is the difference visible without tools?
Yes! Compare photos of Full Moons taken months apart, and you’ll notice the size and brightness difference right away.
If you have a specific question, use the widget above or search online with the current date for the latest updates.
Wrapping Up
Tracking the Moon’s apogee and perigee turns simple stargazing into an adventure. With free tools and a little practice, you can predict and observe these events yourself. Whether you’re snapping photos or just enjoying the view, it brings the wonders of space closer to home. Grab your binoculars and look up—the Moon is waiting! If conditions change, always check reliable sources for the latest data.