However, people in the United Kingdom will have the chance of viewing this unique event as amateur astronomical societies and public observatories will run events that will allow members of the public to safely enjoy the transit. This composite image shows the Mercury transit in May 2016.
From our perspective on Earth, Mercury will look like a tiny black dot gliding across the Sun's face. If you've always wanted to see the phenomenon, now's the time, as it won't happen again until 2032 - and won't be seen again in North and South America until 2049.
Those planning to watch today's event from the ground need binoculars or a telescope with a certified Sun filter; solar glasses are not enough.
Forget blue moons. Even more rare is when the planet Mercury passes right across the middle of the sun, and it's happening Monday. Since each planet orbits the sun during different times of the year, it makes it hard for people on earth to see these transits.
Mercury's transit of the Sun is the flawless opportunity for astronomers to catch a glimpse of the planet.
'That's really close to the limit of what you can see, ' he said earlier this week.
This year's transit will be widely visible from most of Earth, including the Americas, the Atlantic and Pacific Oceans, New Zealand, Europe, Africa, and western Asia. At about 9:20 a.m. CST, Mercury's center will be as close as it is going to get to the Sun's. Periodic, fleeting dips of starlight indicate an orbiting planet.
"Transits are a visible demonstration of how the planets move around the sun, and everyone with access to the right equipment should take a look", Mike Cruise, president of the Royal Astronomical Society, said in a statement from England.
A transit can only take place when the Earth, Mercury and the Sun are exactly in line in three dimensions.