2025, March 13-14: Worm Blood Moon

March 13-14, 2025: A lunar eclipse occurs overnight – a Worm Blood Moon.

Lunar Eclipse, March 14, 2025
Photo Caption – Lunar Eclipse, March 14, 2025

by Jeffrey L. Hunt

Worm Blood Moon

On the night of March 13-14, sky watchers across the western hemisphere are treated to a lunar eclipse, when the lunar orb passes through Earth’s shadow.  The popular press has amplified the poetic and sometimes apocalyptic term “blood moon.” The month’s seasonal Full moon, known as the Worm moon, occurs at 1:55 a.m. on the 14th. The term Worm Bull Moon fills the media’s vernacular.

2022, November 8: Lunar eclipse.
Photo Caption – 2022, November 8: Lunar eclipse.

Round bodies, like planets and moons, cast a shadow into space that is made of two concentric circles.  The outer circle is known as the penumbra, where considerable sunlight reaches.  The center, darker shadow is named the umbra.  Here Earth completely blocks sunlight.

The umbra is the shape of a cone, largest at Earth’s surface, causing nighttime.  The cone’s apex is about 870 million miles into space.  The umbra can be seen in the eastern sky shortly after sunset.

For completeness, the shadow is not fully dark from the atmosphere.  Earth’s veil filters and bends red-orange light into the shadow that softly lights the eclipsed moon. 

Danjon Scale

Astronomy
Photo Caption – 2019, January 20: A lunar eclipse.

The moon does not turn blood red as the descriptive term implies.  Rather its more red-orange, like a new penny.

The intensity of the color depends on the quantity of dust and other pollutants in the atmosphere.

Each eclipse is ranked on a five-level descriptive scale, known as the Danjon Scale.  For example, L=0 reads, “Very dark eclipse.  (Moon, almost invisible, especially at mid-totality.)”  In contrast level L=4 states, “Very bright copper-red or orange eclipse. (Umbral shadow has a bluish, very bright rim.)  The eclipse’s Danjon rating is applied after the event and it cannot be predicted beforehand.

Normally, at a Full moon, the lunar orb passes above or below Earth’s shadow.  When the Full moon crosses the plane of the solar system, the lunar eclipse can occur.

Eclipse Events

Lunar Eclipse, March 13-14, 2025
Chart Caption – 2025, March 13-14: The moon moves through Earth’s shadow, causing a lunar eclipse. Times are Central Daylight Time. (NASA)

Here are the events of the eclipse.

  • 10:55 p.m. CDT (March 13): The moon enters the outer penumbra.  Not much darkening is visible until about 11:45 p.m.
  • 12:09 a.m. (March 14): The eastern limb or edge of the moon enters the darker umbra shadow and a partial eclipse begins.
  • 1:25 a.m.: The total eclipse begins. For the next 66 minutes the moon is fully immersed in the umbral shadow – a Worm Blood Moon.  This is the best part of the eclipse.  Set an alarm.
  • 1:58 a.m.: This is the middle of the eclipse, sometimes known as the maximum eclipse.
  • 2:31 a.m.: The total eclipse ends and during the next 67 minutes a partial eclipse unveils bright sunlight on the moon.
  • 3:48 a.m.: The moon is in the penumbra and it brightens noticeably until it fully exits the shadow.
  • 5:01 a.m.: The eclipse ends.

Eclipse Gear

Lunar Eclipse, May 15, 2022.
Photo Caption – Lunar Eclipse, May 15, 2022.

No special equipment required to see the lunar eclipse.  A binocular or spotting scope is helpful to watch the progress of the eclipse. It an be photographed but with exposures up to several seconds.  To capture it, a camera-mounted tripod is recommended.

Another lunar eclipse occurs on September 7th for sky watchers in central Asia and western Australia.

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