This weekend – August 11-12 and August 12-13, 2018 – present the likely peak nights of the 2018 Perseid meteor shower. Watch from late evening until dawn on both nights. The greatest number of meteors typically fall in the wee hours before dawn, and on a moonless night, you can often spot 50 or more meteors per hour. Fortunately, we have moon-free nights for this year’s Perseids, the likes of which we won’t see again until 2021.
It’s possible to see and photograph bright meteors in moonlight, and, according to NASA’s Meteoroid Office, the Perseids have more fireballs than any other major shower. EarthSky friend Eliot Herman caught the image at the top of this post – a bright meteor, not associated with the Perseid shower – in early July. He wrote on his Flickr page:
Even next to the moon, this is a bright meteor. Brightest meteor captured this location so far in 2017.
From the Northern Hemisphere, you can see a smattering of Perseid meteors in the evening hours. The meteors tend to be few and far between at mid-evening, though this is the best time of night to try to catch an earthgrazer – an elongated, loooong-lasting meteor that travels horizontally across the sky. Earthgrazers are rare but most memorable if you’re lucky enough to spot one.
What if you’re in the Southern Hemisphere? From the Southern Hemisphere, the first meteors – and possible earthgrazers – won’t be flying until midnight or the wee hours of the morning.
In either the Northern or the Southern Hemisphere, the greatest number of meteors streak the sky in the few hours before dawn.
The paths of the Perseid meteors, when traced backward, appear to originate from the constellation Perseus. Hence, this meteor shower’s name.
But you don’t need to know the constellation Perseus to watch the Perseid meteor shower, for the Perseids fly every which way across the starry heavens.
Here’s all you do need to know about the radiant point. As viewed from the Northern Hemisphere, the radiant sits low in the northeast sky at evening and climbs upward throughout the night. The higher that the radiant is in your sky, the more Perseid meteors you’re likely to see. For the Perseids, the radiant is highest before dawn.
That last is true for the Southern Hemisphere, although, from there, the radiant of the Perseid meteor shower never gets very high in the sky. That’s why more meteors are seen at northerly latitudes. But if you’re game, look northward in the wee hours before dawn and you may still see some Perseids.
The earliest historical account of Perseid activity comes from a Chinese record in 36 AD, where it was said that “more than 100 meteors flew in the morning.” Numerous references to the August Perseids appear in Chinese, Japanese and Korean records throughout the 8th, 9th, 10th and 11th centuries. Meanwhile, according to ancient western skylore, the Perseid shower commemorates the time when the god Zeus visited the mortal maiden Danae in the form of a shower of gold. Zeus and Danae became the parents of Perseus the Hero – from whose constellation the Perseid meteors radiate.
The Perseid meteors happen around this time every year, as Earth in its orbit crosses the orbital path of Comet Swift-Tuttle. Dusty debris left behind by this comet smashes into Earth’s upper atmosphere, lighting up the nighttime as fiery Perseid meteors. The meteors start out slowly in the evening hours, begin to pick up steam after midnight and put out the greatest numbers in the dark hours before dawn.
The nice video below is from 2014’s shower, from the Sociedad de Astronomía del Caribe (Astronomical Society of the Caribbean).
Bottom line: Expect these next two nights – the nights of August 11-12 and August 12-13 – to present the peak nights of the 2018 Perseid meteor shower.