How to Read Solar Eclipse Maps

In this article, you’ll learn how to read and interpret a solar eclipse map. We’ll be using the maps available on photoephemeris.com, such as this map of the August 2, 2027, total solar eclipse. You should have some basic knowledge of solar eclipses as we’ll use some eclipse-specific terminology. You can check any terms you don’t know in our Glossary of Solar Eclipse Terms.

Solar Eclipse Map Paths and Lines

Solar eclipse maps have been published for hundreds of years. You can explore many examples on Michael Zeiler’s EclipseAtlas site.

The paths and lines shown on most modern, interactive digital maps are not new – they’ve been included on printed eclipse maps for centuries. Nonetheless, they can sometimes be tricky to interpret. Additionally, there are limitations and subtleties to these maps that can be important to understand, depending on your goals as an eclipse observer.

Here are the different paths and lines we’ll cover in detail:

• Central Line: the line representing the continuum of points where the eclipse lasts longest
• Central Path: the band of locations where totality (or annularity for an annular eclipse) can be observed
• Central Path Northern and Southern Limit Lines: the limits of visibility for totality or annularity
• Northern and Southern Partial Limit Lines: the northern and southern limits of visibility of the partial eclipse
• Max Eclipse at Sunrise: the line of points where maximum eclipse occurs at sunrise
• Max Eclipse at Sunset: the line of points where maximum eclipse occurs at sunset
• Partial Eclipse Start/End at Sunrise: a loop of points where the partial eclipse either starts or ends at sunrise
• Partial Eclipse Start/End at Sunset: a loop of points where the partial eclipse either starts or ends at sunset
• Lines of Equal Magnitude: lines where an observer would see an eclipse of a certain magnitude, e.g. 0.8, 0.6, 0.4, 0.2

It’s important to note that not all eclipses have all lines. If there’s no central line or path, it’s a partial eclipse. If there’s no northern partial limit line, it may be a high-latitude eclipse that misses the North Pole altogether. We’ll look at some examples of these later on.

The Central Path

In the map above, the central path is shown in pink. The blue map pin lies directly on the central line, shown as a thicker solid pink line. The northern and southern limit lines bound the central path and are shown as thinner, solid pink lines.

Why pink? It’s similar to the color of the sun’s chromosphere as seen by the human eye, suggestive of “ totality ”. It’s also very easy to spot against almost any basemap!

An observer located on the central line will enjoy the longest duration of totality, or annularity, in the case of an annular eclipse. This image from TSE2024 was taken during totality at a location on the central line, north of Torreón, Mexico:

The length of totality varies from eclipse to eclipse, and from place to place on the central path. As you move away from the central line toward the central path limits, the duration decreases – but it does not decrease linearly with distance. The reason why becomes much more intuitive when you look at the shape of the moon’s shadow on the earth. Here’s a screenshot from TPE Web showing the outline of the shadow at second contact on the central line near Luxor for TSE2027:

The shadow moves rapidly from northwest to southeast following the central path: the central path is just that – the path of the moon’s umbra on the face of the earth. If you stand at the red pin, you stay longer in the shadow than an observer near either the northern or southern limit. But it’s also clear that being even one third of the way off the central line doesn’t drastically reduce your time in totality. As you approach the path limits, duration shortens quickly.

Partial Limits and Equal Magnitude Lines

As you move north (or south) out of the central path, totality is no longer observed. You’re in the zone of “ nope ”.

The northernmost, solid gray line shown above is the limit of the partial eclipse. If you’re north of here, there’s no eclipse to see at all. The dotted lines – lines of equal magnitude – demarcate how the maximum magnitude decreases as you move away from the central path. Here, the map shows lines of 0.8 (closest to the central path), 0.6, 0.4, and 0.2 (closest to the northern partial limit line).

An important caveat: you’ll see a partial eclipse even when you’re in the central path! Totality lasts only a few minutes. The remainder of the eclipse is observed as a partial eclipse.

You can think of the partial limit lines as marking the path of the moon’s penumbra as it moves in time over the face of the earth.

Lines of Maximum Eclipse at Sunrise and Sunset

This is where the eclipse maps may become less intuitive to read. Eclipses begin and end at sunrise and sunset (some odd cases in polar regions also begin at sunset, just to complicate matters). These lines indicate where local maximum eclipse coincides with sunrise or sunset – with a few subtleties to be aware of.

In the screenshot below, the blue map pin is set at the end of the central path, just beyond the line of max eclipse at sunset:

Take a look at the Local Circumstances panel at the bottom left. This shows the specific timings of the eclipse for an observer at the the blue pin location – the “ local circumstances ”.

I have MAX eclipse selected, occurring at 5:48:19 pm in time zone GMT+6. The mini-eclipse simulator shows the eclipsed sun just beginning to set below the horizon, at an altitude of +0.3°. Third Contact (C3) is shown as not visible. Sunset occurs at 5:51 pm.

So far so good: the idea is that if you’re east of the sunset line, you won’t see max eclipse, as the sun will be set. But you might be wondering “ isn’t the blue pin already just beyond the sunset line? ”, and you’d be correct. It is.

The reason for the disconnect is an important one. Virtually all eclipse maps are calculated using the un-refracted position of the sun. Atmospheric refraction acts to push the sun and moon higher in the sky: there’s a slight increase in the apparent altitude. But the map does not account for that: the sunset line is calculated for “ geometric ” sunset, when the center of the un-refracted sun lies at the ideal horizon, 0°.

Because actual sunset is defined as when the upper limb (12 o’clock) of the sun disappears below the horizon, it occurs later than the “ geometric ” sunset. Hence, you’ll find you can creep a little way beyond the sunset limit and still see max eclipse as the sun is setting. Similarly with the sunrise limit line: you can be a little beyond the line, as sunrise happens earlier due to refraction.

Maximum Partial Eclipse at Sunrise and Sunset

Often, the most interesting places to observe a partial eclipse are at the sunrise/sunset limit lines. This is where the “ devil’s horn ” phenomenon can be observed, as a partially eclipsed sun crosses the horizon. For example, an observer on the coast of Italy north of Ravenna on August 12, 2026, should be able to see the setting, eclipsed sun like this:

To identify attractive observing opportunities for partial eclipses, the best approach is to look along and around the lines of max eclipse at sunrise and sunset.

Start/End of Partial Eclipse at Sunrise/Sunset

Perhaps the most confusing lines of all on an eclipse map, these lines emerge as loops from the underlying mathematics.

As such, you need to look at the context of the line to understand whether it refers to the start or the end of the eclipse at a particular point on the map. An example:

Here, an observer at (1) would see Fourth Contact, C4 (end of partial eclipse) at sunset. However, an observer at (2) sees First Contact, C1 (start of partial eclipse) at sunset. It’s a bit of a brain-twister, but that’s how the geometry of the eclipse plays out.

The clue to knowing whether the dashed line refers to the start or end of the eclipse lies in the topology: at position (1), we’re “ inside ” the closed form of the path, bounded by the max eclipse at sunrise/sunset and partial limit lines. That means the eclipse ends at sunset for these observers.

For those on the “ outside ”, the eclipse starts at sunset.

How do you determine which line marks sunset and which refers to the start/end at sunrise? In most cases, the western loop denotes sunrise, and the eastern, sunset. But there are exceptions: TSE2026 (August 12, 2026) is a notable example, which we’ll review below.

Beyond that, the maps on photoephemeris.com use the same sunrise/sunset colors as TPE uses – lighter orange for sunrise, darker orange for sunset, making the lines straightforward to distinguish. Other maps almost certainly use other conventions.

High-Latitude Eclipses

Some eclipses cross at high latitudes. As a consequence, maps of these events can appear rather odd at first sight. TSE2026 is a good example. The eclipse begins over northern Siberia, tracking almost directly north toward the North Pole, before swinging back south and turning across the Mediterranean. It looks like it starts in the east, tracks westward, then turns back on itself. The path has a strange, exaggerated looping shape. Notice how the sunrise lines (lighter orange) are to the east and the sunset lines to the west – the opposite of TSE2027, shown above:

It all makes much more sense when viewed using an orthographic projection:

Notice how it now resembles the typical form much more closely. You see that the sunrise lines are to the left of the globe and the sunset lines are to the west. The central path tracks around the globe, crossing the North Pole (where digital map libraries struggle to render clean geometry, as you can see), and then ending near Spain.

Next time you look at an eclipse map and wonder what on earth is going on, try switching to the “ globe ” view. Eclipse cartographers have known this projection works well for centuries – for example, see the map by Joseph Jerome le Francai showing the April 1764 eclipse.

Hybrid Eclipses

The term “ hybrid eclipse ” denotes an eclipse which is total in some parts of its path and annular in others. There are three varieties:

• ATA: annular-total-annular
• TTA: total-annular (total at greatest eclipse)
• ATT: annular-total (total at greatest eclipse)

Depending on where you are observing on the central path, you will see either an annular or total eclipse. Most eclipse maps won’t visually distinguish the two or three regions, though. But, if the map has a built-in local circumstances panel, you can spot-check and see clearly which eclipse regime is in effect at different points.

For example, for HSE2031 (the next hybrid solar eclipse), we see a total eclipse at the point of greatest eclipse:

An annular eclipse is observed in Panama, at the eastern end of the path (see the local circumstances panel):

Hybrid eclipse central paths are by nature narrow: the maps above do show the central path and limit lines, but at the zoom level displayed they being to merge into one.

Partial Eclipse Maps

When an eclipse is partial only, that is because the moon’s umbra misses earth, but the penumbra does not. Due to orbital geometry, these misses are either “ too high ” or “ too low ” with respect to earth’s poles, meaning that partial eclipses tend to be biased toward the poles: that’s where the greatest magnitude of the eclipse can be found.

As with all polar eclipses, they produce strange-looking Mercator-projected maps. Here’s PSE2029Dec, December 6, 2029:

Here we see just a northern partial limit line, crossing the Southern Ocean, but no southern partial limit line: that’s because the southern partial limit line does not exist for this eclipse. But is that really what’s going on? Again, an orthographic projection helps to clarify:

The blue pin is at the point of greatest eclipse (magnitude = 0.8910). Things get messy at the poles – when you’re all the way due south, the only way back is northward. In this view, you start to wonder whether what we took to be the so-called “ northern ” partial limit line from the Mercator view is in fact the southern partial limit, and that the northern partial limit does not exist because the sun is set as you move north from the sunrise/sunset limit lines toward Australia.

Eclipses are weird!

Non-Central Solar Eclipse Maps

There’s more. At some point, as a dedicated eclipse-chaser, you will likely encounter a “ non-central ” eclipse. In fact, you may encounter two of them in the year 2043, one total and one annular.

As with partial eclipses, non-central eclipses inherently exhibit high-latitude paths. The “ non-central ” part means that the central line of the eclipse misses earth. As you can see here for TSE2043, the “ southern ” central limit line is defined, but there’s no central line, no northern central limit, and therefore no central path in the normal sense:

The blue pin shows the point of greatest eclipse, and it’s right at the max-eclipse-at-sunrise line. You can think of the max-eclipse-at-sunrise/sunset lines as marking where the umbra starts missing earth altogether. If you were to rotate the globe, you’d see the sunrise/sunset lines coincide with the shape of earth itself at the limb.

Trust Local Circumstances over Eclipse Maps

Eclipse maps are a distillation of eclipse geometry over time. Local circumstances are the precise predicted conditions for a given time and place.

In general, you should trust local circumstances over maps. Maps are excellent for overviews and reasonably precise observer planning. But there are a number of things they typically don’t account for:

• Elevation: the vast majority of maps are calculated for an observer at sea level. If you’re standing on a mountaintop on the map’s central line, then things are different – typically the actual central line will be displaced to the south or north (depending on your location) due to your elevation above sea level. The local circumstances calculation will account for this, however, and give you the ground truth
• Refraction: as we saw above, maps don’t account for atmospheric refraction, meaning that near-sunrise or -sunset circumstances can diverge slightly from the depicted map limit lines
• Lunar Limb Effects: most eclipse maps are calculated assuming a smooth-surfaced, spherical moon. Reality is different. Mountains and valleys on the moon’s surface can increase or decrease the duration of totality at any given place. Our local circumstances calculator assesses the lunar limb topography at the map pin position and calculates the changes to the “ classical ”, smooth-limb contact times, and shows you the delta:

• Due to the effects of the lunar limb, in Orange, NSW, for TSE2028 totality is 11.3s shorter than the smooth-limb model predicts.
• The local circumstances will also detect situations where even though you’re in the central path per the map, in fact you don’t experience totality due to a deep lunar valley; it will also detect the opposite case, where you’re outside the central path, but you do see totality, due to a lunar ridge or mountain that happens to line up just right – here, we have 6.1s of limb-effect totality even though the pin is outside the central path:

Eclipse Maps for Photographers

How should you use eclipse maps as a photographer? In general, the process would go something like this:

1. Understand which eclipses are coming up: consult our eclipse catalog to identify opportunities.
2. Become familiar with the general circumstances of an eclipse: view the eclipse map, such as TSE2028, to see where the central path lies
3. For partial eclipses, explore locations with the highest magnitude, and near the sunrise or sunset limit lines
4. Check the local circumstances to get an overview of eclipse duration and timing
5. Jump into TPE to explore shot opportunities: the azimuth and altitude of the sun during the eclipse will govern what shots are viable. High altitude during an eclipse points you toward telephoto imaging; moderate or low altitudes open the possibility of unique landscape views incorporating the eclipsed sun
6. Carefully check for lunar limb effects, using TPE’s solar eclipse simulator, which will show you the lunar limb profile and the resulting Baily’s Beads

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Congratulations! You’ve gained a thorough grounding in how to read solar eclipse maps. The next step is to start planning to see a solar eclipse – it’s a life-changing experience!