After nearly a decade, Mercury will once again travel between the Earth and sun, marking a relatively rare celestial event that will be visible to sky watchers around the world.
NASA has announced that the agency will broadcast coverage of the May 9 event, showcasing an occurrence that only happens roughly 13 times each century.
As the smallest planet in our solar system makes its passage, it will appear as a silhouetted dot against the sun.
However, it will be too small without the use of a telescope or high-powered binoculars. For those using a telescope or high-powered binoculars who want to observe the event first hand, a specialized solar filter will be needed for safe viewing.
While most of the people living in eastern North America, western Europe, and western Africa will be able to catch the entirety of the event, those in the western U.S., and much of Europe, Asia and Africa will still be able to observe a portion of the transit after sunrise. The transit will begin at 7:12 a.m. EDT on Monday.
Weather conditions may change just in time for onlookers in the eastern U.S. to catch a glimpse of the rare celestial event.
"After what seems like days and days of showers, Monday should finally be a dry day over most of the Northeast and New England," AccuWeather Meteorologist John Feerick said. "Dry and very warm weather is expected in the Southeast, including Florida."
For those living in much of the central U.S., cloudy skies and storms might impede the view of Mercury's passage.
A storm system moving through the nation's heartland is likely to produce showers and thunderstorms from the Midwest to Gulf Coast with the potential for severe storms, Feerick added.
Showers are also expected in the northern Rockies, while dry weather and sunshine will provide a better view to those along the West Coast.
"The planet will make a leisurely journey across the face of the sun, reaching mid-point at approximately 10:47 a.m., and exiting the golden disk at 2:42 p.m.," NASA reports. "The entire 7.5-hour path across the sun will be visible across the eastern United States - with magnification and proper solar filters - while those in the West can observe the transit in progress after sunrise."
Transits of Mercury have long helped astronomers since viewing the event for the first time in 1631. In addition to providing a better understanding of the planet's disk size and the distance between the Earth and sun, transits now allow NASA to test their spacecraft and calibrate their instruments.
A transit of Mercury only occurs when it is passing between the Earth and sun, and passing the Earth's orbital plane, which occurs in early May and November each year. The next occurrence will not be until November of 2019, and then not again until 2032.