Blood Moon 2025: From Aryabhata’s Genius to Tonight’s Spectacle

 

Tonight (7–8 September, 2025), the skies over India and much of the world will stage a grand celestial spectacle — a total lunar eclipse, popularly called the Blood Moon, which is already being hyped across media. Though nit as spectacular as the Total Solar Eclipse, the Lunar Eclipse is special because of its longevity in its occurrence and also the fact that it comes with no risk of seeing with naked eye. Tonight, moon, the lone satellite of our planet earth, which has been so romanticised by the Bollywood movies in the past with soulful melodies sung in honour of the full moon, will be bathed in its coppery red hue for more than an hour – 82 minutes to be precise. The lunar eclipse, and the so called blood moon, will be visible to the naked eye across India and can be seen without any special eye protective wearables.

Courtesy wide publicity by the media and special arrangements made in most cities by science centres, and planetariums, this astronomical moment of awe and wonder is sure to attract many to look at the night sky to witness this celestial theatrical play between our planet earth its satellite, the moon and our Sun, whose movements unfold tonight’s celestial spectacle. Unfortunately, there will still be many, pressured by the astrologers, who may believe in age-old myths and rituals; but for science communicators, like yours truly, it is an opportunity to celebrate both nature’s precision and India’s scientific heritage.

Cosmic Clockwork: Geometry of Lunar and Solar Eclipses

What makes eclipses so enchanting is the delicate geometry of the Earth–Moon–Sun system. The Earth, nearly 12,742 km in diameter, is about four times larger than the Moon, which measures 3,474 km across. Yet because the Moon is so much closer — only about 3.84 lakh km from Earth — while the Sun, though 400 times wider than the Moon (about 1.39 million km across), is also about 400 times farther away (roughly 15 crore km), they appear almost the same size in our sky. This cosmic coincidence allows the Moon to neatly cover the Sun during solar eclipses, and lets the Earth’s much larger shadow engulf the Moon during lunar eclipses. All this is orchestrated by the steady motions of rotation and revolution: the Earth spinning on its axis once every 24 hours, the Moon circling Earth every 27 days, and the Earth orbiting the Sun once a year. Tomorrow’s total lunar eclipse is a direct outcome of this elegant celestial clockwork.

Blood Moon

·    Tonight’s, lunar eclipse will commence around 8.58 PM and end at 2.25 AM on 8 September.  The totality of the eclipse, called the blood moon phase will occur between 11PM to 12.22 AM. During the Totality of the lunar eclipse, the moon will not vanish into blackness but glows red. This blood red appearance is a result of the Rayleigh scattering — the same effect that makes our sunsets crimson. As sunlight passes through Earth’s atmosphere, the shorter blue wavelengths are filtered out, while the longer red wavelengths are refracted into the umbra, softly painting the lunar surface in shades of red and orange. Depending on atmospheric conditions — dust, pollution — the Moon will appear bright copper or an eerie dark maroon.

Tomorrow’s eclipse will be one of the longest of the decade. It provides a great opportunity for Mumbaikars and others from across the subcontinent, to gaze at the night sky and look up and marvel at natures wonders.

Supermoons, Blue Moons, and Media Hype

The media often headlines celestial occurrences under captivating headlines Supermoon, Blood Moon, Super Blue Blood Moon. These terms are media inventions — catchy labels designed to capture attention in an age of short attention spans. They are briefly described below.

• A Supermoon occurs when a full Moon coincides with the Moon’s closest approach to Earth, making it appear up to 14% brighter and 7% larger.
• A Blue Moon is simply the second full Moon in a calendar month.
• A Blood Moon is the reddish Moon during totality, which is happening tonight

When all three occur together, as in January 2018, it is hyped as a “Super Blue Blood Moon.” As Director of the Nehru Science Centre at the time, I remember how we hosted public viewing sessions for that rare trifecta — the first in 35 years. Crowds gathered, telescopes were trained, and for a moment, science and wonder blended seamlessly under the Mumbai night sky.

Similarly, on Buddha Purnima, May 26, 2021, amid the gloom of COVID-19 lockdowns, we live-streamed the Supermoon and lunar eclipse for thousands of viewers. Despite Mumbai’s cloudy skies, the brief glimpses we managed felt like precious gifts in dark times.

These past experiences remind me that while hype sells, it also brings people closer to science. Even exaggerated labels have their use — they make the public look up at the heavens.

Myths, Legends, and the Indian Tradition

For millennia, eclipses have evoked a mixture of fear and reverence. In Indian mythology, the demon Rahu is said to swallow the Sun or Moon, causing an eclipse. According to the Puranas, Rahu, having deceitfully consumed a drop of Amrit during the churning of the ocean, was beheaded by Vishnu. The immortal head became Rahu, and the body became Ketu, forever chasing the Sun and Moon across the sky. Such stories infused eclipses with ritual significance. Even today, many households in India observe Sutak, a period of fasting and ritual purity before and during eclipses. People avoid cooking, eating, or making important decisions. While these practices persist, it is also true that India has always nurtured a parallel, scientific tradition and the mythical beliefs and practices are gradually fading out from society, courtesy the public awareness programmes conducted by science communicators, science centres and planetariums.

Aryabhata: The First Indian to Demystify Eclipses

Nearly 1,500 years ago, ancient Indian mathematician and astronomer Aryabhata (476 CE) revolutionized our understanding of celestial mechanics. In his magnum opus, the Aryabhatiya, he:

• Asserted that the Earth is spherical and rotates on its axis once a day.
• Dismissed Rahu and Ketu as mythological constructs, explaining eclipses as shadows of the Earth and Moon.
• Provided mathematical algorithms to predict the timing and size of eclipses with remarkable accuracy.

Aryabhata’s ideas were bold, often ridiculed by contemporaries including Varahamihira and Brahmagupta, who clung to geocentric orthodoxy. Yet his insights endured. Later Indian astronomers like Lalla and Bhaskara I expanded his methods, and through translations, Aryabhata’s models influenced Islamic and European astronomy.

When we watch midnight Blood Moon, we are witnessing precisely the phenomenon Aryabhata described — shadows cast in celestial alignment. To think that such predictive knowledge was developed in India a millennium before Copernicus is a source of pride and inspiration for all Indians.

Long Journey of Eclipses in Science

Eclipses have long been scientific laboratories. The Total solar eclipse of 1868, observed in Guntur, India, led to the discovery of helium — the only element first identified outside Earth. The 1919 total solar eclipse famously confirmed Einstein’s theory of general relativity, as starlight was shown to bend around the Sun’s gravity.

Even today, astronomers study eclipses to better understand atmospheric conditions, both terrestrial and lunar. Each event is not just a spectacle but also an opportunity to test, measure, and learn.

From Fear to Celebration Change in Public Perception

What strikes me most is how India’s relationship with eclipses has transformed over time from fear to celebration. In earlier times, eclipses were feared as bad omens and roads were seen empty and people closed indoors during eclipses. But today, with rising awareness, they are celebrated as community events. Science centres, planetariums astronomy clubs, schools, and citizen groups organise watch parties, often with telescopes and live commentary. One of my school alumni, Dinesh Badagandi operates a fleet of mobile planetariums under the banner of Tare Zameen Par across Karnataka and adjoining states to create awareness on astronomy and space and an impact assessment study commissioned by the state Government of Karnataka has emphasises its positive impact across the schools in the state of Karnataka.

I am reminded of Prof. Yash Pal, whose live TV commentary during the 1995 Total Solar Eclipse helped millions shed superstition and embrace the eclipse as a natural wonder. His work, and that of countless science communicators, has turned eclipses from portents of doom into festivals of learning. I fondly recall that during an annular solar eclipse in Delhi, the National Science Centre, of which I was the Director had made special arrangement for viewing the solar eclipse and one of the arrangements included a free breakfast for all the visitors, main aim was to dispel the myth of food getting poisoned during eclipse. Almost every visitor, some of them after initial hesitation, joined us in taking food during the eclipse helping bust the myths associated with eclipses.

Tomorrow’s event gives us another chance to continue this tradition — to inspire young minds, to foster curiosity, and to remind ourselves of our place in the cosmos.

 A Midnight Invitation

As midnight approaches on September 7, 2025, step outside. Look up at the Moon as it turns red in Earth’s shadow. Think of the myths of Rahu, the genius of Aryabhata, the experiments of modern scientists, and be happy to be blessed to find our own unique place in this vast universe with billions of galaxies each having billions of their own solar systems with their own planets and their moons, yet as we know today we are perhaps alone in this universe and let us all be proud of our position and let us all join hands in protecting our planet.

The Lunar eclipse which we will witness is not just a spectacle for our eyes, but also for the mind and spirit. A reminder that the same Moon that inspired poets, puzzled ancient sky-watchers, and challenged mathematicians still shines (reflected light) upon us, timeless and unchanging.

So tonight, let us celebrate not fear. Let us observe not merely with our eyes, but with wonder and gratitude. For in the story of an eclipse, we glimpse both the poetry of myth and the precision of science — and the eternal human quest to understand the heavens.

Happy viewing