For astronomy enthusiasts, the intervening night of July 27and 28 promises to be an exciting one as a total lunar eclipse with a duration of 1 hour 43 minutes — the longest in the century — can be observed. But what can be a dampener for the city is a cloudy sky that could make viewing difficult, say experts.
The Ministry of Earth Sciences announced that partial eclipse of the moon will start at 11.54 pm on July 27 following which the moon will be gradually covered by the Earth’s shadow. The totality phase will begin at 1 am on July 28 and the total lunar eclipse will last till 2.43 am. After that, the moon will start to come out of the Earth’s shadow and the partial eclipse will finally end at 3.49 am on July 28.
Explaining a total lunar eclipse, Dr Arvind Paranjpye, the director of Nehru Planetarium said during such an event, the sun, moon and the Earth are on a nearly straight line with the moon being in total shadow of the Earth or in its umbra region.
“The moon will be in the penumbral shadow of the Earth at 10.53 pm on July 27 and nothing will be visible to untrained eyes for the next 30-40minutes. After that, one might notice a gradual change in the brightness of the lunar disk. By 11.54 pm, the moon will be in the umbra of the Earth’s shadow and the dark shadow will progress on the lunar disk, covering crater by crater of the moon. This will be noticeable to the naked eyes. In the next one hour, the moon will be completely inside the shadow of the Earth. At this time, the colour of the lunar disk will be red with its many hues,” Paranjpye said.
He added that another celestial event will take place on the same night. The sun and Mars, the Red Planet, will lie opposite to each other with the Earth in the middle, resulting in Mars coming closer to the Earth and appearing brighter than ever. Although the events are exciting, experts have a word of caution.
“Do not get too excited. Since we are in the middle of monsoon here in India, the sky is likely to be cloudy. So, those expecting to see the surface features of Mars could be disappointed, even after using a telescope. In case of the eclipse, too, viewing would be difficult but since the window is longer, people could hope to see something,” Paranjpye said.
Authorities at the Inter University Centre for Astronomy and Astrophysics (IUCAA) and private astronomy clubs said they were not sure about organising viewing events owing to the monsoon. Sameer Dhurde, science educator and astronomer at IUCAA, confirmed that owing to cloudy skies, a viewing event has not been planned yet.
Sagar Gokhale, the secretary of Jyotirvidya Parisanstha, which is the oldest group of amateur astronomers in the city said: “It will be exciting to watch it and usually, it can be seen with naked eyes, although we get a few telescopes for viewing as well. However, owing to the monsoon, the skies are cloudy and hence, viewing is unpredictable. It is only closer to the date that we will know, although usually, not many viewing events are organised at this time.”
However, Paranjpye said those who want to see the phenomenon should not lose hope as the Nehru Planetarium in Mumbai will organise a live web-cast. “Details will be announced on the website closer to the date,” he said.