As the Moon moves completely into the umbra, it turns a “blood,” or reddish-orange, color (Credit: NASA)

Overnight from Sunday, Jan. 20 into Monday, Jan. 21, stargazers will be treated to what promises to be a spectacular total lunar eclipse. Also being referred to as the “Super Blood Moon” – “super” because the Moon will be at perigee and appear larger than normal, and “blood" because of its reddish-orange color during totality – the eclipse will be seen in its entirety in North and South America, Europe, and western Africa.

January 2019 eclipse visibility (Credit: NASA/Wikipedia Commons/Public Domain)

Lunar eclipses occur when the Earth comes in between the Sun and the Moon. As you may be aware, the Moon shines because its surface reflects light from the Sun. When our planet gets in between the two, its shadow falls on the Moon, resulting in what we refer to as a lunar eclipse. However, instead of going dark, our satellite transforms into what is commonly called a “blood moon.” Though regarded as a bad omen by some, the spooky color is caused by the Sun’s rays bending around the edge of our planet and landing on the lunar surface. However, since the Earth’s atmosphere scatters shorter wavelength light (colors like green or blue), only the longer wavelengths, or the redder end of the spectrum, reach the surface of the moon, making it appear “blood” red.

“The exact color that the moon appears depends on the amount of dust and clouds in the atmosphere,” NASA scientists told Space.com. “If there are extra particles in the atmosphere, from say a recent volcanic eruption, the moon will appear a darker shade of red.”

The Moon does not completely darken as it passes through the umbra because Earth’s atmosphere refracts sunlight into the shadow cone (Credit: Eggishorn/Wikipedia/CC-SA-4.0)

Lunar eclipses do not occur every month because the plane of the moon’s orbit is slightly tilted in relation to that of Earth’s. Hence, the satellite is not always in perfect alignment with the Earth and Sun, which, in addition to a full moon, is necessary for a total eclipse to occur. Unlike a solar eclipse, which can only be seen from specific areas, a lunar eclipse is visible from every place that is on Earth’s night side. They also require no special viewing glasses and typically last about an hour, giving viewers ample time to enjoy the event.

This year’s show will begin at around 10:35 p.m. (EST), when the Earth’s shadow begins to traverse across the front of the Moon and starts blocking the Sun's light. By 11:40 p.m. (EST), the Moon will be “swallowed” up by the Earth’s surface for about an hour. As our planet moves on, it will gradually start to receive the Sun’s rays and return to its full glory by 1:45 a.m. (EST).

The supermoon lunar eclipse as it moved over NASA’s Glenn Research Center on September 27, 2015 (Credit: NASA/Rami Daud)

The January eclipse, the only one in 2019, is particularly favorable for US residents given that it will be visible across the contiguous 48 states. More importantly, totality will begin before midnight, allowing even early sleepers to enjoy the phenomenon. Best of all, it coincides with the Martin Luther King Jr. holiday weekend, which means kids of all ages will be able to stay up and watch the amazing event. If that is not enough incentive to view the eclipse, how about this? The Jan. 20-21, 2019 total lunar eclipse will be the last one until May 26, 2021, and the last one visible from the United States until May 15-16 2022!

Resources: Space.com, NASA.gov