Sky gazers and spectators saw a rare celestial treat with this year's last partial lunar eclipse that was visible in several continents.

The lunar event was primarily visible from South America, Europe, Asia, Africa, western Australia, and nearly in every part of the world except North America and the polar caps of Greenland and northern Russia. This rare sky show even coincided with the 50th anniversary of the Apollo 11 liftoff.

Apollo 11 launched and left Earth on July 16, 1969, and landed on the moon's surface four days later on July 20 of the same year.

Bright Side Of The Moon

Depending on the location and weather, observers saw the Moon partially sinking into the Earth's shadow. In Asia and Australia, the eclipse was visible in the early hours of Wednesday morning, and in Europe, it was visible in the summer sky on Tuesday night, coinciding with the sunset.

According to Space.com, a lunar eclipse happens when the full moon passes through Earth's shadow as it orbits on the opposite of the planet from the Sun. When the moon is completely covering the Earth's shadow, a total lunar eclipse occurs. In a partial eclipse, the moon is only partly passing the umbra or the deepest part of the Earth's shadow. For this event, only 65 percent of the moon covered the Earth's umbra.

"It's difficult to predict the color of an eclipsed moon because the condition of Earth's atmosphere affects it — but with recent volcanic activity spewing dust into the atmosphere, we're hoping for a 'half-blood moon,'" said Paul Cox, chief astronomical officer of Slooh website, which hosted a webcast of the partial lunar eclipse. Spectators also dubbed the celestial phenomenon as the "Half-Blood Thunder Moon Eclipse."

During a total lunar eclipse, the moon turns red because the only light that reaches the surface of the moon are from refracted light from sunrise and sunsets around the Earth. Photos of the partial lunar eclipse posted by spectators on social media sites showed the moon in variations of pinkish, light red, and ruddy orange colors.

Eclipses Come In Pairs

The partial lunar eclipse is actually the pair of the total solar eclipse that occurred last July 2, when the new moon crossed the ecliptic path of the Sun in the sky.

At that occurrence, the new moon blocked a hundred percent of the Sun for a few minutes as seen from parts of Argentina and Chile. Astronomers regarded these events as "cosmic coincidences."

Lunar eclipses are safe to view with the naked eye or with the aid of telescopes and binoculars.