By Michele S. Byers
You’re looking up at the night sky when – whoosh! – a brilliant streak of light whizzes past so quickly you almost miss it. Some shooting stars contain ancient stardust, far older than our young solar system; tiny diamonds manufactured deep within an exploding star somewhere in our Milky Way galaxy over 10 billion years ago.
Everything on Earth except hydrogen atoms, essentially all of you and everything you have ever seen, breathed, or touched, came from nuclear fusion deep within a collapsing star that exploded long ago.
As Carl Sagan said, “we are made of star-stuff.” Shooting stars are meteors. Most are tiny and disintegrate into dust in the atmosphere. A meteor fragment large enough to reach the ground is a meteorite, like the 1969 Allende Meteorite that fell into the Chihuahuan desert in Mexico, or the 2008 Almahata Sitta meteorite that fell into the Nubian Desert in Sudan.
Comet Swift-Tuttle was first recorded by the Chinese in 69 BC. Its orbital path brings it near Earth only about every 133 years. We will need to worry on about Sept. 15, 4479, when it passes extremely close to our Earth-moon system.
But every August we pass right through a dust and meteor cloud strewn through Swift-Tuttle’s orbital path. As the dust and tiny fragments fall through our atmosphere, friction with air incinerates the ancient comet fragments, lighting the night sky with shooting stars. When conditions are perfect, especially after 2 a.m., you might see one every minute.
This year, the Perseids meteor shower started on July 17 and will conclude about Aug. 26, when our planet moves out of the Swift-Tuttle debris field. According to NASA, this August’s lunar cycle is optimal for viewing the Perseids. The new moon was on Aug. 11 and from now through Aug. 17, the waxing crescent moon will set before midnight, making for good viewing conditions in the early morning hours.
Here are some tips for watching the Perseids:
• Get away from light pollution. If possible, leave the city and suburbs, or at least find an unlit large open park or ballfield. Beaches, scenic overlooks, and the Pine Barrens can be excellent. If you live in a dark sky area and have an open back yard, stay home to watch. If you’re feeling ambitious, throw a shooting star party.
• The best time to look is between midnight and sunrise, as the Earth’s rotation turns the upper atmosphere into the fresh, un-bulldozed path of comet debris. Use a reclining chair or blanket, and gaze up at the sky. Your eyes need about 20 minutes to adjust to the dark, so turn off flashlights and be patient.
Spend most of your time looking toward the constellation Perseus. Print out a star map for New York or Philadelphia for the correct time and date to find Mirfak, the brightest star in Perseus, generally to the northeast. You can also locate Mirfak by downloading an astronomy smartphone app. If you’re lucky, you’ll be treated to a steady shower of meteors streaking across the sky.
According to the American Meteor Society, 10 to 50 meteorites drop to Earth each day.
“It should be remembered, however, that two-thirds of these events will occur over ocean, while another one-quarter or so will occur over very uninhabited land areas, leaving only about 2 to 12 events each day with the potential for discovery by people,” the society said.
If you miss the Perseids, you can see other meteor showers this year. The Orionid meteor shower, associated with the famous Halley’s Comet, will peak on the night of Oct. 21-22; the Taurids on Nov. 10-11; the Leonids on Nov. 17-18; the Gemenids on Dec. 13-14; and the Ursids on Dec. 21-22.
Michele S. Byers is the executive director of the New Jersey Conservation Foundation, Far Hills. She may be reached at email@example.com