Sky & Telescope - June 2021 - 36

Worlds Align

path of annularity behaves in an apparently strange manner.
For someone examining the eclipse path from the perspective
of Europe or Asia, the lunar shadow sweeps across Earth in a
typical fashion, from west to east. But for observers in North
America, the shadow appears to move north-northeast, then
north, before ﬁnally curving northwest through central and
northern Canada, northwest Greenland, and on past the
North Pole.
This seemingly odd behavior occurs because the Moon's
shadow is directed toward the north polar region at the
same time Earth is only 10 days removed from the June 20th
solstice, when the North Pole leans most sunward. Consequently, the Northern Hemisphere's sunward tilt causes
the Moon's shadow to trace a path across an area located
well beyond the North Pole. If this eclipse had occurred at
another time of year - around the equinoxes or the winter
solstice - the eclipse path would track sunward of the North
Pole in a normal fashion.
Additionally, because the Moon's shadow strikes Earth at
such an oblique angle, the antumbral shadow path is abnormally wide: averaging about 600 km across. In fact, when it's
ﬁrst projected onto Earth's surface at the start of the eclipse,
its outline will resemble a cigar, with its dimensions measuring 250 km by 1,375 km!

Ground Truth
As shown in the map on the next page, the path of annularity begins in the province of Ontario. Visitors to Wabakimi
Provincial Park (known for its walleye and northern pike
ﬁshing) will be able to see the rising Sun transform into a
ring of light. After passing over James Bay and southern and
eastern portions of Hudson Bay, the path of annularity moves
across northern Quebec and, after crossing the Hudson Strait,
arrives in the northern territory of Nunavut. The Inuit hamlet
of Pangnirtung, on Bafﬁn Island, played host to a total eclipse
in 1979 and is in line for another solar spectacle. This time,
the location's 1,500 inhabitants have an opportunity to see 2
minutes 38 seconds of annularity, beginning at 6:10 a.m. EDT.
The point of greatest eclipse occurs not far from Hans
Island, a tiny, uninhabited barren knoll located off the northwest coast of Greenland in Kennedy Channel of Nares Strait
- the body of water that separates Ellesmere Island from
Greenland and connects Bafﬁn Bay with the Lincoln Sea.
It's here that the ring phase will last longest: 3 minutes 51
seconds. About 20 minutes later, the shadow sideswipes the
North Pole, then turns northwest and leaves Earth's surface a
little more than half an hour later over the Kolyma region of
Russian East Asia.
For observers in New York State, New England, and most
of southeastern Canada (including the Maritime Provinces),
W VERY LARGE ANNULAR Sky & Telescope Senior Contributing Editor
Dennis di Cicco photographed the May 2012 annular eclipse in the late
afternoon from the Karl G. Jansky Very Large Array near Socorro, New
Mexico. The June 10th annular eclipse is the first one visible from North
America since 2012.

JUNE 2 021 * SK Y & TELESCOPE

Sky & Telescope - June 2021

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