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32 ASTRONOMY • JANUARY 2020The annular eclipse June 21 tracks a narrow path across our planet.
Choose the right spot to see it. BY MICHAEL E. BAKICH
Stand under the
RING of FIRE
n annular
eclipse occurs
when the
Moon is too far
from Earth — or Earth is too
close to the Sun — for the Moon
to completely cover the Sun’s disk. The
upcoming eclipse on June 21 is nearly total,
and, as such, it ranks as the third-shortest
annular eclipse in the remainder of the
21st century. With annularity at the eclipse’s
midpoint lasting 38 seconds, only the events
of May 9, 2032, and December 16, 2085, are
shorter. (The annular phases of those events
last 22 and 19 seconds, respectively.)
As with all near-total eclipses, an
observer on the center line away from the
midpoint experiences a longer annular phase
because the Moon lies slightly farther away
and thus appears a bit smaller. The path of
this eclipse also crosses a few countries that
the State Department considers less-than-
totally safe. Visit http://www.travel.state.gov for the
latest information.
Still, such considerations won’t dissuade
dedicated eclipse chasers. They look forward
to each chance to stand in the Moon’s shadow
— or, as in this case, its anti-shadow — and
to experience faraway lands in the process.Eclipse details
The Moon’s antumbra first touches Earth
at 4h47m46s UT at longitude 17°47'50" East
and latitude 1°16'06" North. It remains incontact with
Earth’s surface
for 3 hours
44 minutes
34 seconds, until
8h32m20s UT,
when it vanishes at lon-
gitude 147°35'14" East and
latitude 11°28'20" North.
This eclipse has a magni-
tude of 0.9940 — meaning
that, at maximum, the
Moon will cover 99.4 per-
cent of the Sun’s diameter.
During the eclipse,
brilliant Venus will lie 25°
west of the Sun. Shining
at magnitude –4.5, this
planet may become visible
up to 10 minutes before
annularity, if your location
places it high enough in
the sky.
The only other nearby planet
will be Mercury, which lies a bit
more than 14° east of the Sun.
Unfortunately, at magnitude 3.0, our
solar system’s innermost world is too
faint to be visible.Crossing Africa’s heart
In 2020, 13 countries will experience the
annular eclipse. It starts at sunrise in the
Republic of Congo, just east of the city of