Kolkata: Astronomy enthusiasts across Kolkata are in for a treat as the occultation of Saturn by the Moon will be visible from various Indian cities, including Kolkata, after midnight on Wednesday, July 24 into the early hours of Thursday, July 25. The celestial event, during which Saturn will disappear behind the lunar disc and reappear after some time, will be visible for over 30 minutes in several locations, unless monsoon clouds play the spoilsport.
Occultation is a celestial phenomenon where one astronomical body hides another from view.
As the Moon revolves around the Earth, it sometimes obscures a planet or star, making it appear as if the celestial body is hiding behind the Moon. This is known as occultation.
While total solar eclipses are a type of occultation, where the Moon completely covers the Sun due to their similar apparent sizes, occultations of planets and stars occur as the larger Moon disc obscures the view of these smaller objects, said M P Birla Institute of Fundamental Research scientific officer Bipash Das Gupta.
On the night of July 24, the Moon, which will be about 80% illuminated, will obscure Saturn in the Aquarius constellation (Kumbha Rasi), which has a magnitude of 0.9. The Moon itself will also be in the Aquarius constellation.
Occultation occurs when the Moon, orbiting Earth in an elliptical path, crosses its closest position, ‘perigee’, on July 24, at 11.11 am.
Observers should start tracking the event at least 30 minutes before the predicted disappearance time and continue for 15 minutes after the reappearance to capture the full phenomenon. The occultation of Saturn by the Moon is part of a series that happens roughly every 18 months with a 4-year interval, explained Das Gupta.
The next occultation will be on Aug 21, but it will not be visible from India. This event offers a unique opportunity for sky watchers and astronomers to observe the dance of celestial bodies and understand the dynamics of our solar system, he added.