These images of the Annular
Solar
Eclipse on October 14, 2023 were taken from my roof patio in
Houston, TX. They show the moon eclipsing the sun. Here in
Houston, the sun was nearly 90% covered! What makes the above
crescent of fire rotate? Simply, the moon passed in front of and
to the side of the sun, so that it appears to rotate. Neither
the sun nor the moon actually rotated significantly during these
3 separate images each taken 11 minutes apart. We merely see
different parts of the sun as the moon passes in front of it!
Note in the right image of the sun above, a sunspot is visible
at the top right "horn" of the crescent, and not visible in the
other horns since it was then covered by the moon.
Solar
eclipses are very interesting phenomena in that they happen more
frequently than we think (about 200 times per century). A total
solar eclipse, however, is relatively rare when the moon
completely blocks the sun. The same point on earth will only
experience a total solar eclipse about once every 3-4 centuries.
Furthermore, lunar eclipses, where the moon passes into earth’s
shadow, are more frequent since the earth is larger than the
moon and therefore casts a larger, longer shadow. While solar
eclipses are very narrow and only visible in certain paths of
the moon’s shadow across the earth, lunar eclipses may be viewed
by all inhabitants on earth that happen to be in their night
time when the eclipse occurs. One way to think about it, is that
every night, we all experience the earth eclipsing the sun, but
some nights while we are eclipsed, we see the moon also
eclipsed!
Eclipses also happen 6 months apart when the
moon’s orbit crosses the plane of the ecliptic at full or new
moon! More precisely, after 6 full revolutions of the moon
around the earth, the sun and moon aligned to a point to create
another eclipse. Weather is also a factor in eclipses. Of
course, it should be relatively clear (cloud free) to view or
image the ellipse, yet the eclipse itself can also change the
weather! In Houston, the temperatures dropped by more than 10
degrees during the eclipse. It felt warm at the beginning and
end of the eclipse, but chilly during eclipse maximum. Also 20
minutes or so before the maximum, as the moon’s shadow crossed
Texas, a strong but steady 2-3 minute wind gust formed, likely
due to rapidly falling temperatures a hundred miles away and
moving 20-40 miles per hour away from annular totality.
In the above image, if you look closely or zoom in you might
notice the edge of the sun is relatively smooth as would be
expected, however, the edge of the moon appears a bit ragged due
to mountains and craters visible at that edge. Furthermore, the
below image shows the sun and moon at near maximum eclipse with
around 90% coverage.