*The annual Perseid meteor shower peaks this year from late Tuesday night into early Wednesday...the moon will be somewhat of a hindrance, but there will be a special bonus in the eastern sky*
Paul Dorian
Perseid meteors appear to radiate from the constellation Perseus in the northeast sky. Credit: WSFA 12 News (Montgomery, Alabama) /NASA
Overview
The annual Perseid meteor shower began on July 17th and will continue through August 23rd, but the peak viewing times will be during the late-night hours on Tuesday, August 12th to the pre-dawn hours of Wednesday, August 13th. The Perseid meteor shower comes every July/August as the Earth passes through a cloud of dust that comes from Comet Swift-Tuttle as it approaches the sun. The moon will be somewhat of a hindrance this year as it will be just beyond its full moon phase which took place on August 9th. One special bonus for sky watchers, however, will be the conjunction of Venus and Jupiter visible in the eastern sky during the pre-dawn hours so look for that feature as well early Wednesday.
Details
The Perseid meteor shower has already begun, and it will reach a peak for viewing centered between the late-night hours of Tuesday, August 12th and the pre-dawn hours on Wednesday, August 13th. This year, the almost-full moon will be a hindrance for viewing likely resulting in only the brightest stars breaking through.
The Perseids happen every year in the July/August time period as the Earth crosses the orbital path of Comet Swift-Tuttle. This comet takes about 133 years to orbit the sun and it last rounded the sun in the early 1990s. Credit Earthsky.org/Guy Ottewell.
Every year, from around July 17 to August 24, our planet Earth crosses the orbital path of Comet Swift-Tuttle, the parent of the Perseid meteor shower. Debris from this comet litters the comet’s orbit, but we don’t really get into the thick of the comet rubble until after the first week of August. Earth's gravity pulls in chunks of small rocks from Comet Swift-Tuttle comprised of iron-nickel, stone, and other minerals. These small rocks turn into bright balls of hot gas when they enter the Earth's atmosphere. As darkness falls, the meteors appear to come from the constellation Perseus, hence the name; although late in the evening, the meteors actually originate higher in the sky than the constellation.
A photo of Perseid meteors seen in 2019 from Macedonia. Courtesy spaceweather.com/Stojan Stojanovski
It is estimated that Perseid meteoroids hit our atmosphere at about 132,000 miles per hour to produce the annual light show and this meteor shower is usually rich in “fireballs” because of the size of the parent comet. Comet Swift-Tuttle has a huge nucleus - about 26 kilometers in diameter - whereas most other comets are much smaller with nuclei only a few kilometers across. Comet Swift-Tuttle has a very eccentric – oblong – orbit that takes this comet outside the orbit of Pluto when farthest from the sun, and inside the Earth’s orbit when closest to the sun. It orbits the sun in a period of about 133 years. Every time this comet passes through the inner solar system, the sun warms and softens up the ices in the comet, causing it to release fresh comet material into its orbital stream. Typically, meteors are only the size of pebbles, some as small as a grain of sand, but Comet Swift-Tuttle produces a large number of meteoroids that are large enough to produce “fireballs”. In fact, the Perseid meteor shower is considered the “fireball champion” of all of the annual meteor showers. Hopefully, skies will cooperate on the peak nights/early mornings of Tuesday, August 12th – Wednesday, August 13th (50/50 chance), but if not, there will be other opportunities this year for viewing meteor showers. The next one of note will be the Orionids which peak on October 20-22, that one brings about 10-20 shooting stars per hour.
"On Monday morning, the conjunction of Venus and Jupiter was spectacular--truly a magnificent sight," says Marek Nikodem, who sends this picture from Szubin, Poland: See the red streak next to Jupiter? "That's a Perseid meteor," says Nikodem. "This was a good start to the week. I'm hoping for more." (Courtesy spaceweather.com)
Venus and Jupiter conjunction
One final note, a special bonus this particular year…Venus and Jupiter are converging in the eastern dawn sky for a spectacular conjunction. The closest approach (from our viewpoint on Earth) will take place during the next few nights when the two planets will shine like a bright double star in the pre-dawn sky. So take a look to the eastern sky early Wednesday morning to see the convergence of the two planets and you might catch a shooting star at the same time.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com