Over the last days of July, stargazers are set for a spectacular event: the combination of three meteor showers – the Delta Aquariids, the Alpha Capricornids, and the Perseids – that will illuminate the night sky this weekend. Since the moon is currently in its incipient phase, the shooting stars will be clearly visible, particularly from the Southern Hemisphere and the southern latitudes of the Northern Hemisphere.
According to NASA, when the Earth orbits the sun and encounters the lopsided orbit of a comet, whose icy surface leaves behind rocks and dust as they boil off from the sun’s heat, this debris falling toward our atmosphere ignites, causing the phenomena we know as meteor showers. “A meteor is a space rock – or meteoroid – that enters Earth’s atmosphere. As the space rock falls toward Earth, the resistance – or drag – of the air on the rock makes it extremely hot,” experts from NASA explained.
“What we see is a “shooting star.” That bright streak is not actually the rock, but rather the glowing hot air as the hot rock zips through the atmosphere. When the Earth encounters many meteoroids at once, we call it a meteor shower.”
The Southern Delta Aquariids meteor shower – occurring each year between July 12 and August 23 – is suspected to originate from Comet 96P Machholtz. The meteors number ten to 20 per hour and fly at 25 miles per second. About five to ten percent of these meteors leave behind glowing, ionized gas trails that are visible on the sky for one or two seconds after the meteors pass. This shower will peak on Saturday night and will be best visible for people from the Northern Hemisphere by looking to the southern part of the sky.
Following the Delta Aquariids’ peak will be the peak of the Alpha Capricornids, which are caused by debris from the comet 169P/NEAT. Although this shower isn’t very strong – emitting usually less than five meteors per hour – it tends to produce bright fireballs during its peak and can be observed equally well by people from both hemispheres.
Although the Perseids (caused by the comet Swift-Tuttle) will only peak towards the middle of August, astronomers warn that, since the moon will be full during their peak, these meteors will not be very visible. However, this shower already started on July 7, and is currently emitting about ten meteors per hour. Since on Saturday night, this will be combined with the peaks of the Delta Aquariids and the Alpha Capricornids, stargazers are set for an amazing spectacle.
By Andrei Ionescu, Earth.com Staff Writer