Treasure Coast skywatchers are getting ideal conditions this week to catch one of the year's most reliable meteor showers, as the Perseids reach their peak with no moonlight to wash out the show.
The Perseid meteor shower runs from late July into late August but peaks around August 10-12, according to Jon U. Bell, associate professor of astronomy and director of the Hallstrom Planetarium at Indian River State College.
Bell said the shower is named for the constellation Perseus, which rises in the northeast around midnight and marks the "radiant" — the point in the sky the meteors appear to stream from.
"It's the point in space that we're kind of headed toward when we run into this big stream of debris in our path as the Earth travels in its orbit of the sun," Bell said.
That debris comes from Comet Swift-Tuttle, which left a trail of dust and small particles in its wake as it passed through the inner solar system. Earth crosses that trail every August, and the tiny particles — most no bigger than a grain of sand — burn up in the atmosphere roughly 60 to 70 miles overhead.
"What it does is it burns up and it heats up the air that it passes through, and that lights up a column of air, and that's that streak of light that you see," Bell said. Some meteors travel at more than 100,000 miles per hour, he said. This year's peak coincides with a new moon, meaning there's no moonlight to interfere with viewing.
"Without the moonlight up there to interfere, it's a good time to see the Perseids," Bell said.
Bell said Wednesday and Thursday nights — Aug. 12 and 13 — are the best remaining chances to catch the peak. Viewing should improve after midnight, when Earth's rotation carries observers into the leading edge of its orbital path, directly into the debris stream.
"When the Earth is revolving about the sun, it's also rotating on its axis," Bell said. "As we get on toward midnight, the Earth rotates around, face into the path that we're traveling, and the shower picks up."
Earlier in the evening, meteors tend to be fewer but slower-moving, which can sometimes produce bright fireballs, he said.
Bell recommends getting away from streetlights and finding a park that's open overnight. Beachside parks along the Treasure Coast work well because they offer a dark, unobstructed view to the east.
Bell and members of the Treasure Coast Astronomical Society plan to view the shower from the Fort Pierce jetty on Hutchinson Island.
Pepper Park, a county park on Hutchinson Island, is open overnight and is another option for local viewers.
No telescope or binoculars are needed — Bell said a wide, naked-eye view of the sky works best.
His tips for viewing:
- Face east, then look up toward the top of the sky
- Keep any light sources behind you
- Bring a lounge chair or blanket to lie back comfortably
- Dress for cooler ocean breezes and bring bug protection
- Be patient — meteors can come in unpredictable bursts
"You could go for like 15 minutes and see nothing” Bell said. "And then suddenly, boom, boom, boom."
Clear skies are essential, and Bell noted that recent afternoon cloud buildup could affect visibility on any given night. If it's cloudy, he said, there's nothing to do but wait for the next clear night — or a shower next year.
The Perseids have been observed for centuries and were known in medieval times as the "Tears of St. Lawrence," tied to the saint's Aug. 10 feast day. Bell called the shower "the old faithful of meteor showers" for its consistency year after year.
For Florida viewers, Bell said the Geminid meteor shower in December is often an even better show, since Florida's mild winter weather makes for comfortable late-night viewing compared with colder northern climates.