The night of the Blood Moon and the Red Planet

Night of 27th July is very special for the sky watchers. On this night two special events are going to happen. These two events are very rare to happen together. One is the longest total lunar eclipse of the 21st century and other is the opposition of planet mars. 

27th July Lunar eclipse is the longest eclipse of the twenty first century. Usually, total Lunar eclipses are longer because earth's shadow is very big at the point of lunar orbit. Earth's shadow size is approximately 2.6 times bigger than moons diameter. Even at the speed of  3,682 kilometer per hour moon takes much time to cross earth's shadow. Time of totality depends on the from which part of the shadow moon moves. Last lunar eclipse on 31 January 2018 moon passes from the southern part earth's umbral shadow. It's totality lasted for the 1 hour and 6 minutes. On 31 January moon was at perigee means nearest point to earth in its orbit. Moon was big and near to the earth so it could crosses earth's shadow comparatively fast. 

31 January 2018 Super moon Eclipse, photo taken by me 

On 27th July moon will be at apogee, means it will be at farthest point from earth in orbit so its size will be comparatively small. At this time moon will be passing through the center part of the earth's shadow so it will take time for moon to cross earth's shadow. Moon will be eclipsed for the 1 hour and 43 minutes. This is the duration of totality only. Entire Lunar eclipse is much longer. There are some stages are involved in lunar eclipse which help us to understand path of the moon through earth's shadow. 

Lunar eclipse happens when moon passes through earth's shadow but earth forms two kind of shadows one is Umbra this is center part of shadow which is dark and there is another shadow around umbra which is called Penumbra. Penumbra is the lighter than umbra. When Lunar eclipse happens moon first touches the outer portion of the penumbra this is the beginning of the penumbral eclipse. Next stage moon touches earth's dark shadow umbra this the beginning of partial eclipse. From here onward one can see earth's shadow traveling on the moon's surface. Naked eyes feels that its moving slowly but though telescope one can see the speed of earth's shadow when it gradually gulps moons surface features. After that moon totally goes into earth's umbra and it starts showing red color because some light from sun passes through the earth's atmosphere and fall on moons surface. Redness of eclipsed moon depend upon the activity of the earth's atmosphere. 

Different stages of Total Lunar Eclipse

Then there is a stage called as maximum eclipse this is the middle of the eclipse. After maximum eclipse moon starts traveling to the other end of shadow and touches inner edge of umbra shadow this is the end of total eclipse and again partial eclipse start. Moon start moving out of the umbra and enters in penumbra here, partial eclipse ends. In the last stage moon travels through penumbra and then come out entirely from earth's shadow.

27 July 2018, Eclipse timings for Indian Sky watchers are as follows 

Penumbral Eclipse will start at 10:44 pm IST (Indian standard time)
Umbral Eclipse will be start at 11:54 pm IST
Totality will start at 1:00 am IST on 28 July
Maximum eclipse at 1:52 am IST
Totality ends at 2:43 am IST
Partial eclipse ends at 3:49 am IST
Penumbral eclipse ends at 4:58 am IST

Total Duration of eclipse is 6 hours and 13 minutes 
Total duration of totality is 1 hour and 43 minutes

Animation of total lunar eclipse stages of 27th July 2018, Timings are given in Universal standard we can add Indian zone time of 5:30 hrs to get Indian timings, Sours: earthsky.org

Many people do not find Lunar eclipse exciting as solar eclipse. Might be because of their long duration but lunar eclipses have significance in many ways. Lunar eclipse at ancient times gave opportunity to figure out earth's shape and its size. Nowadays also one can measure size of earth by measuring earth's shadow size on lunar surface. If you don't want to do any measuring just see earth's curve shadow and imagine how people find out its spherical shape.

With the Total Lunar Eclipse, the red planet Mars is aligning opposition with Earth on the same day and coming close to earth. On this day we will get opportunity to see eclipsed blood moon with red planet Mars. They will be near to each other during eclipse. So, do not miss the opportunity to see these two red celestial objects on 27 July night.

Eclipse moon and red planet mars can be observe near to each other, Source: Stellarium