Mercury's rare 'transit' across the sun today: Here's how you can see it

The celestial event will be visible from all parts of India for varying durations depending on the location, starting around 4:40 pm.

Stargazers will have a rare opportunity on Monday to witness Mercury fly directly across the face of the sun, a sight that unfolds once every 10 years or so, as Earth and its smaller neighboring planet come into perfect alignment.

In Delhi, Mumbai, Kolkata and Chennai, the event will begin at 4:41 pm.

In Delhi, the event can be seen for a duration of about 2 hours 20 minutes, in Kolkata about 1 hour 26 minutes, in Mumbai about 2 hours 24 minutes, and in Chennai about 1 hour 45 minutes.

Dwarka in Gujarat will experience the longest transit (2 hour 43 minutes).

Port Blair in the east will see it for only 54 minutes.

In Shimla and Chandigarh the event can be seen for over 2 hours.

It will be difficult to see the Mercury at transit over the face of the Sun without some form of aid such as binoculars or telescopes.

The Earth Sciences ministry suggested that a proper solar filter will be required to avoid viewing the sun with the naked eye such as aluminized mylar, black polymer or welding glass of shade number 14

Mercury is too small to see without high-powered binoculars or a telescope, and looking directly at the sun, even with sunglasses, could cause permanent eye damage.

Fortunately NASA and astronomy organizations are providing virtual ringside seats for the show by live-streaming images of the transit in its entirety and providing expert commentary.

The tiny planet, slightly larger than Earth's moon, will start off as a small black dot on the edge of the sun at 7:12 a.m. Eastern (1112 GMT). Traveling 30 miles (48 km) a second, Mercury will take 7.5 hours to cross the face of the sun, which is about 864,300 miles (1.39 million km) in diameter, or about 109 times larger than Earth.

"Unlike sunspots, which have irregular shapes and grayish borders, Mercury's silhouette will be black and precisely round," Sky and Telescope said in a press release.

The event will come into view in the western United States after dawn, with the transit already in progress. The show will end at sunset in parts of Europe, Africa and most of Asia.