Kenya is set to witness a rare natural spectacle on Friday night

The world will on Friday experience  the longest lunar eclipse in the 21st century.

The eclipse will last for about four hours and will be visible across Europe, Asia, Africa, South America, Middle East and Australia.

The total eclipse, where the earth will be plunged in total darkness when the earth’s shadow completely covers the moon, will last for about one hour and 43 minutes.

The totality in Nairobi will begin at 10:30 pm while viewers in cities like Cairo in Egypt will see it at 9:30 pm.

Partial eclipse, where the moon will be partly covered, will last for 3 hours and 54 minutes.

This will be the first central lunar eclipse since June 15, 2011 though A partial solar eclipse occurred on July 13, 2018.

Part of the Moon’s shadow fell near the South Pole, so partial coverage of the Sun was visible in parts of southern Australia.

The eclipse was also visible in Stewart Island in the far south of New Zealand.

Unlike a solar eclipse, a lunar eclipse is safe to watch with the naked eye; you’re only looking at the Moon, at night, which is quite safe.

A solar eclipse is potentially dangerous because viewing a solar eclipse involves looking at the Sun, which can damage your eyesight.

The next total lunar eclipse after the one on Friday will take place on January 21 next year.

Other incidences of central lunar eclipses will occur in January 2084, May 2087, September 2090, June 2094, and April 2099.

Obviously, none of the those who will witness Friday’s and next year’s spectacle will be alive to see it happen.

A lunar eclipse occurs when the Moon passes directly behind Earth and into its shadow. This can occur only when the Sun, Earth, and the Moon are aligned (in syzygy) exactly or very closely so, with the planet in between. Hence, a lunar eclipse can occur only on the night of a full moon. The type and length of an eclipse depend on the Moon’s proximity to either node of its orbit.

During a total lunar eclipse, Earth completely blocks direct sunlight from reaching the Moon. The only light reflected from the lunar surface has been refracted by Earth’s atmosphere. This light appears reddish for the same reason that a sunset or sunrise does: the Rayleigh scattering of bluer light. Due to this reddish color, a totally eclipsed Moon is sometimes called a blood moon.

Unlike a solar eclipse, which can be viewed only from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. A total lunar eclipse lasts a few hours, whereas a total solar eclipse lasts only a few minutes as viewed from any given place, due to the smaller size of the Moon’s shadow. Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions, as they are dimmer than the full Moon.