It is a rare celestial event today: A Mercury transit
Mercury transit is a rare occurrence when Mercury will pass across the sun and it will be visible from the earth. Mercury is the closest planet to our star, and the probability of witnessing such an event is probably more than witnessing venus coming across the sun which is even rare than Mercury. The last time this cosmic event occurred was back in 2016.
This kind of event only happens about 13 times in a century and it is recorded to happen again in 2032 roughly. It is a rare transit where the planet will pass across the sun and it will be seen as a little dot in front of the surface of the sun from the earth.
Obviously, only one-half of the people living on this planet are going to witness it. So people living in South America, North America, Europe, and Africa will be able to witness the action. This is a bit disappointing for people living in India, Australia and most parts of Asia and Alaska. Mercury's transit will last for around five and a half hours, starting at 4:35 am PST (6:05 pm IST on Monday).
Mercury and Venus are the only two planets that can cause this transit for us to watch. And, as mentioned above, since, Mercury is the closest planet to the sun, the probability for Venus to be in such kind of transit event becomes even rarer. It is said, that for Venus, this transit will happen in around 2117. As Mercury moves across the Sun, it causes a slight drop in the Sun's brightness, letting scientists search for more planets that orbit distant stars.
Mercury is tiny and will appear as an extremely small, dark dot passing through the desk of the sun. NASA recommends people to not look at the sun directly as it can seriously damage the eyes, but to wear sun-protected glasses and probably watch it with a telescope because of the planet's small diameter. People in the Us should not miss it for the world because this event will not occur for them till 2049. But, NASA will share the real-time images of Mercury passing across the sun from its Solar Dynamic Observatory.