We're About to Experience The Longest Lunar Eclipse in This Century

July is shaping up to be an excellent month for astronomy fans.

Overnight on July 27 and 28, skywatchers in the Eastern Hemisphere will be treated to the longest lunar eclipse set to occur in the 21st century, EarthSky reports.

Astronomers expect the total eclipse to last for a full 1 hour and 43 minutes, with the partial eclipse – which occurs before and after the total eclipse phase – lasting for 3 hours and 55 minutes.

A lunar eclipse occurs when the Sun, Earth, and Moon are directly aligned, and the Moon's orbit brings it directly into Earth's shadow.

This particular eclipse will last so long because the Moon will pass directly into the darkest region of Earth's shadow, known as the umbra, which will also give the Moon a reddish "blood moon" sheen.

July's full moon will happen at the same time as the Moon's apogee – which is when the Moon hits its furthest point from Earth in its monthly orbit, according to EarthSky.

It will be the smallest and furthest full moon of the year, which means the Moon will take more time to pass through Earth's dark shadow, making the eclipse last longer.

The longest possible lunar eclipse is 1 hour and 47 minutes, according to EarthSky. Here's when to catch it (times in UTC):

• 6:24 pm: The penumbral eclipse begins when the Earth's penumbra starts to touch the moon
• 7:30 pm: The total eclipse can be seen when the moon is fully red
• 8:22 pm: Maximum eclipse
• 9:13 pm: Total eclipse ends

Just a few days after the lunar eclipse, Mars will pass by Earth at its closest point to us since 2003.

On July 31, the Red Planet will be only 35.8 million miles (57.6 million km) away from Earth, making it clearly visible to the naked eye.

Stargazers in the Eastern Hemisphere will easily be able to see both Mars and the blood moon on July 28 and 29.

This article was originally published by Business Insider.