April 29th’s “No Show” Annular Solar Eclipse

The first and only annular solar eclipse of 2014 has a path that just clips Antarctica, at a location so remote that no one on Earth will get to see the event.

Update: Partial phases of April 29th's solar eclipse were widely seen across the southern part of Australia. See the bottom of this post for a photograph of the event.

The word "rare" gets tossed around a lot when it comes to astronomical events. You've probably heard lots of newscasters breathlessly describe "rare planet alignments" (not usually), "rare black holes" (hmm), and, most recently, a "rare blood Moon eclipse" (hardly).

Well, Tuesday will offer a celestial event that really is rare: an annular eclipse of the Sun that no one on Earth will see!

Path of April 29th's annular solar eclipse

The path of the annular solar eclipse on April 29th only barely touches Earth's surface — in one of the most remote spots on the planet.
Fred Espenak / NASA

It's not that no one wants to see this event — after all, there are thousands of adventurous skygazers worldwide who'd go anywhere, within reason, to see a total or annular solar eclipse. (An annular eclipse occurs when the Moon doesn't completely cover the Sun, briefly creating a "ring of fire" in the sky.)

But not this time. As the map at right shows, the track of Tuesday's annular eclipse just barely clips Antarctica.The longest view you could possibly get, standing on the ice at 131°15.6′ E, 79°38.7′ S, would be 49 seconds of annularity with the Sun pinned to the horizon.

In fact, the centerline of this eclipse's path doesn't touch Earth at all, and that's rare in itself. According to calculations by celestial gurus Fred Espenak and Jean Meeus, 3,956 annular eclipses occur in the five millennia from 2000 BC to 3000 AD. But only 68 of them (1.7%) yield this kind of non-central event.

The Ultimate Eclipse Getaway

I put this simple question to the rabid devotees of the online Solar Eclipse Mailing List: "Is the upcoming annular eclipse unlikely to be observed by anyone at all?"

It drew a lot of responses, many with a similar refrain: it's "only" an annular eclipse. Notes David Dunham, who's done his share of globe-trotting for celestial events, "If it were a total eclipse, certainly, someone would organize at least a plane to fly there to observe above any clouds."

Aussie observer Dave Herald, who lives in Murrumbateman, New South Wales, closer to Antarctica than most and thus arguably well positioned to give it a go, also demurred. The zone of annularity is "far more remote than anywhere in the Northern Hemisphere," he says. "Throw in the overall poor circumstances (low altitude at the best), the fact that it is annular (not total), and the complete lack of civilization (in the form of bases), and it is anything but surprising that no one will be observing it."

On rare occasions, diehard "umbraphiles" have indeed trekked to Antarctica for a solar eclipse of the total variety. That was certainly the case in 2003, when the eclipsed Sun appeared surreally juxtaposed with the frozen landscape.

Simulations by "saros seeker and satellite whisperer" David Dickinson suggest that two orbiting spacecraft, ESA's Proba 2 and NASA/JAXA's Hinode might glimpse annularity for a few seconds. Watch Dickinson's eclipse simulation and judge for yourself.

Australia Lucks Out — Again

April's partial solar eclipse from Albany, Australia

In the coastal town of Albany, Western Australia, overnight rain gave way to clear skies on April 29th. Observers there saw the Moon cover 56% of the Sun's disk.
Jay M. Pasachoff / Williams College

You've got to be envious of Dave Herald and his countrymen Down Under. Sure, Australia's a big place, but by my count it's been crisscrossed by the paths of two total and two annular solar eclipses in the past 15 years. And come Tuesday afternoon, anyone with a clear sky near its southern coast will see the Moon cover roughly half of the Sun. (Here's a table of eclipse predictions for various Australian cities.)

And if you don't feel like cashing in a gazillion frequent-flyer miles to dash off to Sydney, the team at Slooh plan to offer a live webcast of the partial eclipse. So does Italian astronomer Gianluca Masi via his Virtual Telescope Project.

COMMENT