2023 Solar and Lunar Eclipse Guide

A solar eclipse occurs at New Moon, when the Moon passes directly in front of the Sun. Although the Moon is about 400 times smaller than the Sun, it’s also 400 times closer to the Earth, and, as a result, both the Sun and the Moon appear the same size in the sky.

If the Moon completely covers the Sun, then observers on Earth experience a total solar eclipse. For a few minutes, the sky turns dark, the stars and planets appear and the ghostly white solar corona - the outermost layer of the Sun’s atmosphere - can be seen.

However, the Moon’s orbit is not a perfect circle, and on some occasions it’s a little further away than average. When that happens, the Moon doesn’t appear large enough to obscure the Sun and we have an annular eclipse. Instead of the solar corona, observers on Earth will see a ring of white light - the visible part of the Sun’s disc.

If the Earth, Moon, and Sun aren’t perfectly aligned, we won’t have a total or annular eclipse at all. The Moon’s orbit is inclined slightly, and as a result, eclipses don’t happen every month, but on some occasions we might see a partial eclipse.

This happens when part of the Sun’s disc is obscured. The view will vary, depending upon your location on Earth, but when a significant portion of the Sun is covered, observers can detect a drop in light and the Sun appears to have a chunk cut out of it.

A partial solar eclipse can also be seen during a total solar eclipse, both before and after totality, and by anyone not lucky enough to be within the path of the Moon’s shadow across the Earth.

The Earth, like all objects, casts a shadow, and a lunar eclipse occurs when the Moon passes through that shadow. Since the shadow is caused by the Sun, a lunar eclipse can only happen at full Moon, when the Moon is on the opposite side of the Earth from the Sun.

As the Earth’s shadow is quite large, totality can sometimes last up to several hours, as the Moon slowly moves through it. Since the Earth’s atmosphere refracts sunlight, its shadow is not completely dark, and the Moon will typically take on a coppery hue. On rare occasions, when the atmosphere is polluted (for example, from a volcanic eruption), less light is refracted and the shadow is so dark the Moon can almost disappear completely.

The Earth’s shadow is made up of two parts - the central, darkest area is called the umbra, while the outermost, much lighter area is called the penumbra. The Moon will pass through both areas during a total eclipse.

A partial eclipse occurs when the Sun, Earth, and Moon are not quite in alignment and the Moon isn’t completely engulfed in the umbra.

If the Moon doesn’t touch the umbra at all, it might only pass through the penumbra. Given that the penumbra is not nearly as dark, the Moon’s light is only slightly dimmed during a penumbral eclipse, and it can often be difficult to notice any change at all.

Lastly, one of the big differences between a solar and a lunar eclipse is that you can view a lunar eclipse from anywhere the Moon is visible at that time - you would just need to adjust for the observer’s time zone.

For example, imagine there are two observers; one on the eastern coast of North America and one on the west. If mid-eclipse were to occur at midnight, eastern time, then the east coast observer would see it high in the sky, while the observer on the west coast would see the same eclipsed Moon rising in the southeast at 9 pm.

Eclipses almost always come in pairs. Since it takes nearly four weeks for the Moon to orbit the Earth, the Moon turns full (when lunar eclipses can occur) about two weeks after New Moon (when solar eclipses can occur).

As such, you’ll find that eclipses will typically alternate between lunar and solar, with about six months between each pair (although you’ll occasionally find a penumbral lunar eclipse popping up between the two pairs to break up the pattern).

For example, in 2023 there are four eclipses, starting with a hybrid solar eclipse on April 8th, followed by a penumbral lunar eclipse on May 5th. Six months later, there’s an annular solar eclipse on October 14th, and then we have a partial lunar eclipse on October 28th.

Incidentally, if you live in North America, it’s worth noting that October’s annular eclipse is the first of two major solar eclipses to be visible from the continent within the space of six months.

The first solar eclipse of next year, on April 8th, 2024, is a total solar eclipse that will surpass the total solar eclipse of August 2017. (If you haven’t already made arrangements to see it, it’s certainly advisable to start now!)

As we take a closer look at each eclipse, we’ll review where you can observe it and give you an idea of what you might expect. For solar eclipses, the top five locations are provided, while for lunar eclipses there’s a table showing the timings for major cities where the eclipse will be visible.

If you’d like to know the details for your specific location, you can find out more by visiting the Time and Date site. There’s also a very useful interactive map of solar eclipses from Xavier M. Jubier.

May’s penumbral lunar eclipse is visible throughout most of the world - with the exception of both North and South America, Greenland, Iceland, and the UK. Just as the hybrid solar eclipse a few weeks previously cut a path from the Indian Ocean to the Pacific, this particular eclipse will be best seen from Asia and Australia.

East of those locations (for example, northeastern Russia) will see the eclipse begin as the Moon sets, while those to the west (including Africa and Europe) will see the eclipse ending as the Moon rises.

Things are a little different if you’re in New Zealand; most observers on the northern island will miss the end of the eclipse, as the Moon will set before the eclipse comes to an end. However, those on the southern island can see the eclipse in its entirety.

Unfortunately, penumbral lunar eclipses can often be a non-starter, as the Moon is only passing through the outermost portion of the Earth’s shadow, and the shadow is not nearly as dark as it is near the center. Consequently, the Moon may only be slightly dimmed, and the chances are you may not notice a difference at all!

Unfortunately, like the penumbral eclipse six months previously, most observers in the Americas will be out of luck for this eclipse. However, it’s visible from start to finish in Africa, Asia, and Europe with western Australia, Greenland, and Iceland also being lucky enough to see it.

Observers in eastern Australia may see the penumbral stage, with much of mid-Australia seeing the start of the partial phase, but the Moon will then set before the eclipse comes to an end.

As for the Americas, if you live in the northeastern corner of Canada, you’ll miss the start of the eclipse, but you may see a partially eclipsed Moon rising instead. Similarly, if you’re in the northeastern corner of the US or eastern Canada, you’ll miss the partial eclipse entirely but may catch the end of the penumbral phase as the Moon rises.

Central America is out of luck, whereas observers in the northeast of South America will also see the Moon rising as the penumbral eclipse ends. Those in the northeastern area of Brazil will see the partially eclipsed Moon rising, at around the time of mid-eclipse.

The partial phase of the eclipse lasts for 1 hour and 17 minutes but only has a magnitude of 0.12. This means that only a small part of the Moon’s surface (roughly 6%) will appear reddened by the Earth’s shadow.

Lastly, for this eclipse, the Moon will appear to the south of the three brightest stars of Aries, the Ram. Brilliant Jupiter shines to its east, making this a potential photo op for astrophotographers.