MARQUETTE — Monday, millions will be treated to a very rare astronomical event: a total eclipse of the sun. This only occurs on a given spot of the planet once every 375 years.

Monday’s swath of darkness will exclusively cross the United States from Oregon to South Carolina and “the path of totality” along the way will be up to 70 miles wide.

Michigan is outside this path but will still see a partial solar eclipse where the moon covers part of the sun’s disk. Parts of southern Michigan will have about 80 percent blockage of the sun midday. Motorists are reminded to use extra caution during the eclipse and to not pull over on the side of the roadway to view the event.

“Public safety is our priority,” said Col. Kriste Kibbey Etue, director of the Michigan State Police, in a press release. “We ask that motorists keep moving and avoid stopping in traffic or alongside of the road, which could be very dangerous. If you are going to stop, please find a safe location to park.”

Safety first, added another state official.

“This truly is a once-in-a-lifetime event and many Michiganders will make their way south to the best viewing locations,” said State Transportation Director Kirk T. Steudle.

“Allow yourself extra time to reach your destination and make sure you have a safe viewing spot.”

The longest duration of totality will be 2 minutes, 41.6 seconds in Giant City State Park, just south of Carbondale, Illinois, and the greatest extent (width) will be near the village of Cerulean, Kentucky, located in between Hopkinsville and Princeton.