Synchronous Fireflies: Tennessee’s Mysterious and Magical Light Show

There are few childhood memories that are more enchanting than chasing fireflies in your grandmother’s backyard. Every June, the firefly lovers of the world converge on the Great Smoky Mountains in Tennessee in order to witness a rare species of firefly that puts on one of nature’s rarest and most beautiful light shows.

During a short period of time in the late spring, a species of firefly known as photinus carlolinus flash in unison. Scientists are not entirely sure why these specific fireflies light up and go dark all together. Some experts speculate that the synchronous flashing is part of a mating ritual. Both scientists and casual observers agree that the uncanny glow of thousands of fireflies lighting up and darkening in perfect time is one of the most magical sights on Earth.

One of the best ways to view the synchronous fireflies during their peak luminescence is to enter a National Park Service lottery which offers parking passes to visitors. Guests who obtain parking passes take a relatively simple hike into a forest in the Great Smoky Mountains which offers prime firefly viewing. Most years, over 20,000 people from virtually every continent enter the lottery. Because the firefly habitat is so delicate and sensitive to light pollution, only 800 lucky souls are selected by the National Park Service to view the synchronous fireflies each season.

There are a handful of private companies which offer exclusive firefly excursions, including a posh camping trip which includes a meal served around a campfire. In the interest of protecting the fireflies, access to them during their prime mating period—which is when they shine the brightest—is limited. If you have your heart set on seeing the synchronous fireflies of the Great Smoky Mountains—it is best to start planning very far in advance.

Gatlinburg, Tennessee is one of the most heavily trafficked tourist hubs in the United States. There is something truly mystical about walking the streets of bustling Gatlinburg, only to retreat into a nearby forest pulsing with soft, synchronized bursts of light. The synchronous fireflies only flash for a few hours a night during a two week window each year. Bioluminescence is truly a breathtaking natural phenomenon. It is certainly worth the effort to keep applying for a National Park Service parking pass year after year in the hope that you will one day be able to view one of nature’s loveliest light shows.