A rare astronomical event took place on Monday as Mercury passed directly between the Earth and the sun.
This event, called a transit, was visible around much of the globe as the solar system's smallest planet appeared to slowly glide across the surface of the sun.
However, Mercury is too small and too far away from Earth for people to be able to see its transit without the help of binoculars or telescopes, as well as the right protective equipment.
Additionally, clouds blocked the view of the astronomical event for many.
The transit of Mercury is a rare event that happens roughly 13 times every 100 years.
Due to the way in which Mercury and the Earth orbit the sun, these transits occur either in May or November with the most recent occurring on Nov. 8, 2006.
Those who missed Monday's transit will not have to wait too long for the next one with Mercury passing between the Earth and sun again on Nov. 11, 2019. However, after that astronomers will have to wait until 2032.
Transits of Venus also occur periodically but are much rarer than the transit of Mercury. These only occur every 105 to 121 years with the next one not happening until 2117.
Unlike Mercury transits, Venus transits are visible without the use of binoculars or telescopes, but the proper protection is needed to prevent optic damage from the sun.
Mercury leaves the sun's disk in about 20 mins during today's #MercuryTransit. Here's the transit so far:https://t.co/JPHdKtqE3A— NASA (@NASA) May 9, 2016
#ICYMI: Here's the full #MercuryTransit. For 7.5 hrs today, Mercury was visible as a tiny black dot crossing the sunhttps://t.co/sYXWe5NufG— NASA (@NASA) May 9, 2016