Set your alarms: a fiery eclipse is coming Thursday, but this one’s for the early birds.

At 5:31 a.m., minutes before sunrise, the moon will steal the show by stepping in front of the sun to create what astronomers call a partial annular eclipse. The moon is currently a few thousand miles too far from the Earth to fully block out the sun, but it will obscure about 70% of the sun despite being 400 times smaller.

“This is somewhat unusual,” says Derrick Pitts, Chief Astronomer at the Franklin Institute. “Annular eclipses are a little more rare.”

It’s also known as a “ring of fire,” which is what it will look like to viewers further north watching it pass over Canada, Greenland, and across the Arctic to Siberia. Americans on the east coast will be able to see a crescent-shaped slice of sun, but it will still be blindingly bright, so don’t forget to wear approved eclipse eye protection. Sunglasses, even very dark ones, don’t filter out enough radiation to be safe.

Philadelphia will have one of the best vantage points along the east coast, but it will take some work to get a good view, Pitts said. You’ll need to find an unobstructed view of the east-northeast horizon, so those on the Jersey Shore will be in luck, he said.

For those further inland, fear not: Pitts shared some viewing tips. Find a place with high elevation and an unobstructed view, like a high rise building or the Ben Franklin Bridge. To get oriented, face the Delaware River and make a quarter-turn to the left. Of course, Pitts noted, humid morning haze could foil even the most careful plans.

The maximal eclipse will happen right before sunrise in Philadelphia, but viewers in the city will still be able to see the moon’s shadow covering the sun for over an hour. Scientists will also have an eye to the sky as they use the pattern of the eclipse to improve their measurements of the moon’s size and speed. Studying eclipses has helped scientists figure out that the moon is spiraling away from us, meaning that in “millions of years” we won’t have total eclipses anymore, Pitts said.

If Philadelphians decide to sleep in, they’ll have to wait a few years for the next good look at an eclipse — in 2024.