A total lunar eclipse took place on May 26, 2021. The photograph above was taken at 04:18:23 AM, in Mountain View, CA, when the moon was in maximum total eclipse. The total eclipse began at 4:11 AM Pacific Time, and ended at 4:25 AM.
A total lunar eclipse occurs when the sun, earth, and moon are in alignment. Normally, light from the sun illuminates the moon directly. During the eclipse, the earth is positioned between the sun and moon, blocking sunlight from directly reaching the moon.
When the moon is in the shadow of the earth, how is it still visible? And why does it have the color that it does?
The earth has an atmosphere, which affects light passing through it. Light on a path to the center of the earth (wherever the sun is high, during mid-day), travels on a path mostly perpendicular to the surface, reaching it directly, which blocks it from the moon. The atmosphere scatters light with shorter wavelengths (towards the blue end of the spectrum–producing a blue sky), while allowing any remaining light to pass through.
Light skimming the edge of the earth (wherever sunrise or sunset is occurring) travels on a path more parallel to the surface. Some of it may not reach the earth’s surface, and eventually exits back into space. It has a longer distance to travel through the atmosphere, so long that all blue light is scattered away, resulting in the distinctive red and orange colors of the sunrise or sunset. Also, the atmosphere refracts, or bends, the light, to roughly follow the curvature of the earth. When the light exits the atmosphere, some of it is now on a path to the moon, after “wrapping around” the earth. Refraction favors colors towards the reds and browns, so the light illuminates the moon in a “blood” red color.
The amount of light reaching the moon during a total lunar eclipse is only a small fraction of the amount when lit directly by the sun. The blood moon is visible, but it is much less bright.
The May 26 eclipse was unusual, termed a “Super Flower Blood Moon.” What is the meaning of the term?
- “Super” describes a full moon that occurs when the moon is in its closest approach to earth. The moon’s orbit around the earth is elliptical, so the distance between the two varies. A super moon appears larger than at other times, though it may not be noticeable to the eye.
- “Flower” describes a full moon in May.
- “Blood” describes the red color seen during a lunar eclipse.
It is rare to have a Super moon and a Blood moon occurring together—rare enough to drag myself out of bed at 3 AM.
How long does the total lunar eclipse last?
It is different for each eclipse. Stages and times of the total lunar eclipse, on May 26, 2021 in Mountain View, CA, appear below:
1:47 am: Penumbral Eclipse begins
2:44 am: Partial Eclipse begins
4:11 am: Total Eclipse begins
4:18 am: Maximum Eclipse
4:25 am: Total Eclipse ends
5:52 am: Partial Eclipse ends
6:00 am: Moonset
6:49 am: Penumbral Eclipse ends
How often does a lunar eclipse occur?
Following is a list of lunar eclipses in 2018 through 2024:
| January 31, 2018 July 27-28, 2018 | Total Lunar Eclipse Total Lunar Eclipse |
| January 20-21, 2019 July 16-17, 2019 | Total Lunar Eclipse Partial Lunar Eclipse |
| January 10-11, 2020 June 5-6, 2020 July 4-5, 2020 November 29-30, 2020 | Penumbral Lunar Eclipse Penumbral Lunar Eclipse Penumbral Lunar Eclipse Penumbral Lunar Eclipse |
| May 26, 2021 November 18-19, 2021 | Total Lunar Eclipse Partial Lunar Eclipse |
| May 15-16, 2022 November 8, 2022 | Total Lunar Eclipse Total Lunar Eclipse |
| May 5-6, 2023 October 28-29, 2023 | Penumbral Lunar Eclipse Partial Lunar Eclipse |
| March 24-25, 2024 September 17-18, 2024 | Penumbral Lunar Eclipse Partial Lunar Eclipse |
Each eclipse is visible in only some parts of the world.
Source article: May 26, 2021 — Total Lunar Eclipse — Mountain View, CA, USA https://www.timeanddate.com/eclipse/in/usa/mountain-view?iso=20210526
Moon Dipping Below a Ridge
Following is a sequence of three photographs showing the moon dipping below a ridge.
Sunrise and Moonset
On the day of the total lunar eclipse, May 26, 2021 in Mountain View, sunrise and moonset occurred at nearly the same time (within nine minutes of each other), in nearly opposite directions (181 degrees apart):
sunrise: 5:51 am, 62 degrees
moonset: 6:00 am, 243 degrees
Double Exposures
Photographs featuring both landscape and moon can be difficult to take, because the moon is usually very bright relative to the landscape. Exposing for a dark landscape can overexpose the moon; exposing for a bright moon can underexpose the landscape.
Rather than trying to capture both landscape and moon in the same exposure, each can be photographed individually, with the best exposure for each. The images can then be combined, opening up all sorts of possibilities—including artistic, creative, devious, or fraudulent—for inserting a moon into another photo of a landscape or anything else.
Two such combined images appear below. The first was combined in-camera using a double exposure feature, and the second was done in Photoshop.
