On April 4, 2015, the Moon will turn a shade of red in many parts of the World as the Earth moves between the Sun and the Moon, casting its shadow on the Moon's surface.
The Earth's atmosphere is to blame for turning the Moon red during a Lunar Eclipse. ©bigstockphoto.com/ prajit48
Animation: Next Eclipse in your city
This will mark the first Total Lunar Eclipse of the year and the third eclipse in a series of four total eclipses of the Moon in the 2014-2015 lunar tetrad.
10 facts about the April 4, 2015 Total Lunar Eclipse
Earth Casts its Shadow
The Moon does not have any light of it's own – it shines because its surface reflects sunlight. During a Total Lunar Eclipse, the Earth moves between the Sun and the Moon and cuts off the Moon's light supply. When this happens, the surface of the Moon takes on a reddish glow instead of going completely dark.
The red color of a totally eclipsed Moon has prompted many people in recent years to refer to Total Lunar Eclipses as Blood Moons.
The science of Total Lunar Eclipses
Why Red?
The reason why the Moon takes on a reddish color during totality is a process called Rayleigh scattering. It is the same mechanism responsible for causing colorful sunrises and sunsets and the sky to look blue.
Colorful Sunlight
We all know from our school science textbooks that even though sunlight may look white to human eyes, it is actually composed of different colors. These colors are visible through a prism or in a rainbow. Colors towards the red spectrum have longer wavelengths and lower frequencies compared to colors towards the violet spectrum which have shorter wavelengths and higher frequencies.
Earth's Atmosphere
The next piece in the puzzle of why the sky looks blue and a totally eclipsed Moon turns red is the Earth's atmosphere. The atmosphere is about 300 miles (480 kilometers) thick and is made up of different gases, water droplets and dust particles.
When sunlight entering the Earth's atmosphere strikes the particles that are smaller than the light's wavelength, it gets scattered. Not all colors in the light spectrum, however, get equally scattered. Colors with shorter wavelengths, for example those towards the violet spectrum, are scattered more strongly than those with longer wavelengths like red and orange, which pass through the atmosphere. This light then gets bent or refracted back to the surface of the Moon and gives it the reddish-orange glow that Total Lunar Eclipses are famous for.
Light blue band visible on the Moon's surface. ©bigstockphoto.com/Medardus
Look for a Blue Band
Veteran eclipse watchers will tell you that if you look really hard right at the beginning and just before the end of totality, you may detect a light blue or turquoise band on the Moon's face. This happens because the Earth's Ozone Layer scatters red light and lets through some of the blue light that gets refracted to the Moon.
How to view a Lunar Eclipse
Many Shades of Red
The Moon can take on different shades of red, orange or gold during a Total Lunar Eclipse, depending on the conditions of the Earth's atmosphere at the time of the Eclipse. The amount of dust particles, water droplets, clouds and mist can all have an effect on the shade of red. Volcanic ash and dust in the atmosphere can also lead to the Moon turning dark during an eclipse.
Fun fact: If you were lucky enough to see a Total Lunar Eclipse from the Moon, you'd see a red ring around the Earth. In effect, you'll be seeing all the sunrises and sunsets taking place at that specific moment on Earth!
Sunrise and sunset times in your city
The Danjon Scale was created by French astronomer, André-Louis Danjon.
Measuring the Eclipsed Moon's Brightness
Scientists measure the appearance and brightness of a Total Lunar Eclipse using a five point scale – ranging from 0 to 4 – called the Danjon Scale. A Lunar Eclipse is ranked and assigned a value on the Scale at the time of mid totality.
Observation from Chelsea, Victoria, Australia at 06:07am AEST (UTC+10). 

On Friday–Saturday —depending on observer's timezone— a total lunar eclipse occurred as the Moon was in the shadow of the Earth. As normal during such an eclipse, the Moon became faint and turned completely red as bluer light was  by the Earth's atmosphere.  Totality of 1 hour and 43 minutes was the longest in the 21st century.

People were able to observe the eclipse from Australia, Africa, Asia, Europe, and South America.  A volunteer named José Jiménez uploaded a photo of the incident today from  in , Catalonia, Spain, featuring the Moon, Mars, and the  on the same photo.

German astronaut  took photos of the Moon from the International Space Station and uploaded them to  on the same day.

According to timeanddate.com, the timeline of the eclipse was as follows.




Event

Time (UTC)July 27



Start penumbral eclipse

17:14:47



Start partial eclipse

18:24:27



Start full eclipse

19:30:15



Maximum eclipse

20:21:44



End full eclipse

21:13:11



End partial eclipse

22:19:00



End penumbral eclipse

23:28:38



Mars was also visible near the Moon; coming this week, reported , closer to Earth than at any time since 2003.


Panoramica Luna de Sangre, Marte y la Via Lactea (42842944115).jpg|An observation from Alt Empordà in Girona, Catalonia, Spain, featuring the Moon, Mars and Milky Way, uploaded on July 31, 2018. Imzage taken at 23:31, on July 27, 2018. 
Visibility Lunar Eclipse 2018-07-27.png|Visibility map of the eclipse.
Watch Today full moon eclipse full video live 28th - full moon eclipse video from India - red moon.webm|India. 
ImageNA.svg|
Alexander Gerst - Lunar Eclipse 2018 - photo 2.jpeg|International Space Station. 
Alexander Gerst - Lunar Eclipse 2018 - 43637755162 0aa8cd69c9 o.jpg|International Space Station. 
SAM 0613 (28791930147).jpg|Location unknown. Includes Mars. 04:44, July 28, 2018 
File:SAM 0649 (42777978065).jpg|Location unknown. Includes Mars. 05:13, July 28, 2018 
End of blood moon over Brastad old cemetery.jpg|Sweden. 22:36, July 27, 2018. 
Lunar Eclipse 3310.jpg|Observation from Austria, 22:15, July 27, 2018. 
Eclipse de Luna de sangre desde Planetario de Madrid 03.jpg|Madrid, Spain. 23:29, July 27, 2018. 
2017 Total Lunar Eclipse (43663340212).jpg|Switzerland. 20:25, July 27, 2018. 
Eclipse de lune 2018 (29816524528).jpg|A series of images from  Télescope Celestron NexStar 8 SE, 

File:The Moon Before Eclipse in 20180727, Fuzhou 01.jpg