Lunar Eclipses
I took this picture of the lunar eclipse of 2025 at 2:30 AM (CDT) on March 14. Here is useful information about lunar eclipses from the NASA website:
What is a lunar eclipse?
A lunar eclipse occurs when the Sun, Earth, and Moon align so that the Moon passes into Earth’s shadow. In a total lunar eclipse, the entire Moon falls within the darkest part of Earth’s shadow, called the umbra. When the Moon is within the umbra, it appears red orange. Lunar eclipses are sometimes called “Blood Moons” because of this phenomenon.
Lunar eclipses occur at the full moon phase. When Earth is positioned precisely between the Moon and Sun, Earth’s shadow falls upon the surface of the Moon, dimming it and sometimes turning the lunar surface a striking red over the course of a few hours. Each lunar eclipse is visible from half of Earth.
Why does the Moon turn red during a lunar eclipse?
The same phenomenon that makes our sky blue and our sunsets red causes the Moon to turn red during a lunar eclipse. It’s called Rayleigh scattering. Light travels in waves, and different colors of light have different physical properties. Blue light has a shorter wavelength and is scattered more easily by particles in Earth’s atmosphere than red light, which has a longer wavelength.
Red light, on the other hand, travels more directly through the atmosphere. When the Sun is overhead, we see blue light throughout the sky. But when the Sun is setting, sunlight must pass through more atmosphere and travel farther before reaching our eyes. The blue light from the Sun scatters away, and longer-wavelength red, orange, and yellow light pass through.
During a lunar eclipse, the Moon turns red because the only sunlight reaching the Moon passes through Earth’s atmosphere. The more dust or clouds in Earth’s atmosphere during the eclipse, the redder the Moon will appear. It’s as if all the world’s sunrises and sunsets are projected onto the Moon.
The Moon’s orbit is tilted about 5 degrees compared to the plane of Earth’s orbit around the Sun. Because of this tilt, the Moon as seen from Earth’s perspective usually passes above or below the Sun when it passes between us and the Sun. The tilt of the Moon’s orbit prevents us from having monthly solar and lunar eclipses.