When the Moon’s shadow swept across Earth on April 20th, tens of thousands traveled to Australia, Timor-Leste, and Indonesia to witness the celestial spectacle.

More often than not, eclipse-chasers have a challenging time getting to the path of a total solar eclipse, and that was certainly true for anyone who wanted to see April 20th’s event. The path of totality crossed very little land — it started in the southern Indian Ocean, barely clipped the westernmost corner of Australia, and crossed Timor-Leste and eastern Indonesia before sliding off into the Pacific Ocean.

Eclipse track for hybid solar eclipse in April 2023
Here’s the path of the solar eclipse on April 20, 2023. Hybrid (or “annular/total”) solar eclipses occur only about once per decade; the previous one was in November 2013, and the next will take place in November 2031.
Sky & Telescope / Fred Espenak

However, such remoteness didn’t deter thousands of “umbraphiles” who crammed onto Australia’s remote Exmouth Peninsula or aboard cruise ships off the Australian coast. Eclipse day dawned nearly cloud free all along the track, even though a powerful cyclone had battered the region just a week beforehand.

The event was a geometric oddity: a hybrid solar eclipse, one that is total in the middle but annular at its beginning and end. This occurs because the Moon appears slightly larger at the mid-eclipse point than it does at the beginning and end of the eclipse track, which are one Earth radius farther from the Moon. So the Sun’s disk is completely covered from that midpoint but appears as a thin or broken ring at either end of it.

Chromosphere during April 2023 eclipse
Mid-eclipse as seen from the island of Kosrae, just a few miles north of the path of totality (which was only 6 miles wide at that point). The chromosphere forms a broken ring all around the Sun’s circumference in this image taken with a Lunt 35 hydrogen-alpha telescope and DMK41 CCD camera.
Patrick Potevin

Above is an example of what that looks like, as seen by an observer on the tiny island of Kusrae, a tiny island in Micronesia some 3,800 miles to the northeast of Exmouth and very near the limit of totality’s visibility. This unusual geometry, which occurs roughly once per decade, meant that totality on April 20th would be brief — a meager 1m 16s at the point of greatest eclipse (near Timor-Leste).

Still, the event was a big draw: Some 15,500 visitors surged into the area in and around Exmouth, ordinarily a quiet town of roughly 3,000, and thousands more packed cruise ships off the coast. Sky & Telescope’s group of 140 enjoyed totality while anchored in Exmouth Gulf aboard P&O Cruises’ 2,000-passenger Pacific Explorer, and I traveled literally halfway around the world (Boston to Perth) to join them.

Pacific Explorer panorama during totality
Even with 2,100 passengers aboard (including 140 in the Sky & Telescope tour group), there was plenty of deck space aboard P&O Cruises' Pacific Explorer during April 20th’s total solar eclipse. Go here to see the interactive 360° panorama.
Pat Espenak

Timor-Leste was another popular destination for eclipse-chasers. Bob Kieckhefer observed from near Com, on the island nation’s eastern tip. “We had a few small clouds in the area, but they were well away from the Sun during totality,” he reports. “We saw great shadow bands both before and after totality.”

Special Effects

Given the near-perfect match of the solar and lunar disks in the sky, this eclipse offered some interesting phenomena that are not commonly seen during total solar eclipses. For example, Baily’s beads (the bits of Sun still in view along the Moon’s crenulated limb just before and after totality) were especially dramatic. Long swaths of the brilliant, crimson chromosphere rimmed the merged disks, punctuated by large prominences on the leading edge. The largest of these jutted 50,000 miles (six Earth diameters) high.

Two views of April 2023 total solar eclipse
Left: The lunar disk just barely covered the Sun on April 20, 2023, yielding beautiful views of the crimson-colored chromosphere. This is a combination of two images taken at the beginning and the end of totality, so the chromosphere is visible on both sides of the limb. Pavel Mironov

Right: Taken from a tiny strip of beach on uninhabited Ah Chong island in the Timor Sea, this view through a Nikkor 400-mm lens and 1.4× teleconverter captures the dramatic prominences on display during the total solar eclipse on April 20, 2023. Eliot Herman

Of course, the feathery solar corona was the big draw, and it did not disappoint. Several bright streamers fanned out all around the disk — the kind of well-spaced arrangement that’s characteristic of the corona’s appearance near solar maximum. (During solar minimum, the streamers are usually concentrated at the Sun’s equatorial latitudes.)

Coronal streamers (April 2023)
Pronounced streamers radiate from all parts of the eclipsed Sun in this composite of five images (14000 to 12 second) with a Canon 6D MkII camera at ISO 200 and William Optics 72-mm f/6 refractor.
Joo Beng Koh

Anyone who’s seen totality will tell you that photos just can’t fully capture what the human eye sees. I asked Fred Espenak, one of the great masters of solar-eclipse imaging, to render this eclipse as it might have been seen by someone watching through binoculars — and then create a second version to maximize all of the tortured magnetically-driven detail present in the corona. Here’s the result:

April 2023 totality visual-HDR comparison
Compare these images of April 2023’s corona, processed to appear as the eye would see it using binoculars (left) and to maximize the coronal detail (right). Both views utilized 10 images with exposures from 12000 to 12 second, using a Nikon D7500 camera at ISO 400 and a Tamron 170-500 mm lens (at 500 mm) and f/8.
Fred Espenak

“No photo has the dynamic range to reproduce the range of brightness see with the naked eye,” Espenak says. “The prominences are particularly hard to to capture in such a ‘naked-eye’ composite. They really should be much brighter than shown, but this would completely wash out their color.”

Meanwhile, because totality’s path was less than 30 miles (50 km) wide, the sky never got very dark at mid-eclipse — though Jupiter (just 6° away) and Venus were easily seen.

All Eyes on the Americas

This was the first total solar eclipse since December 21, 2021, an equally challenging event observable only from Antarctica or the Southern Ocean. But now diehard eclipse-chasers will get a reprieve. Next up is an annular (ring) solar eclipse on October 14th that crosses the western U.S., the Yucatán, Central America, and northern South America.

Six months later, on April 8, 2024, the Moon’s shadow races over central Mexico before heading across much of the U.S. and the Canadian Maritimes. It’ll be the second such event for Americans in a span of seven years, and this time totality will last up to a generous 4½ minutes. Check out Sky & Telescope’s extensive resources for maximizing your view of next April’s highly anticipated event.

Got eclipse fever? Be sure to check out the exciting Sky & Telescope eclipse expeditions planned for the Yucatán Peninsula (October 2023), a “Mexican Riviera” cruise (April 2024), Easter Island (October 2024), and beyond.


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