Mercury passing in front of sun on Monday

In a rare celestial event, Mercury passes in front of the sun on Monday.

The stellar show, which only happens about 13 times a century, starts at 7:35 a.m. when the tiny planet begins the transit across the sun, according to NASA.

Mercury will be close to the centre of the giant star at approximately 11:20 a.m.

The entire 5.5-hour event will be visible, weather permitting, in the eastern United States and Canada, and all Central and South America.

It’s not safe to look directly at the sun, as it can damage your eyes. Only view the transit with proper safety equipment such as binoculars and telescopes fitted with special filters.

But you will be able to safely view the innermost planet’s heavenly trek thanks to NASA. The space agency will livestream the event starting at 10:30 a.m. Monday on the NASA Facebook page at Facebook.com/NASA.

There also will be an informal roundtable during which scientists will answer questions via Facebook and Twitter using hashtag #AskNASA. The event also will be broadcast on NASA TV at NASA.gov/multimedia/ nasatv.

Monday will be prime time for scientific study. When one of the planets passes in front of the sun, it causes a slight dip in the sun’s brightness as it blocks a tiny portion of the sun’s light, according to NASA. That allows scientists to search for exoplanets, which are planets orbiting distant stars.

Only Mercury and Venus transit the sun. While transits of Mercury happen more often, transits of Venus are rare. That last happened in 2012. The next one will be in 2117, NASA said.