The annual Orionid meteor shower, originating from Halley's Comet, has commenced alongside the comet's return to the inner Solar System. As per the American Meteor Society, the meteor shower spans from September 26 to November 22, with its peak occurring on October 21 in the pre-dawn hours, featuring a maximum of 20 shooting stars per hour.
Meteor showers occur due to comets leaving dust and debris in the inner solar system, intersecting Earth's orbital path, and producing meteors-small rock or dust fragments that burn up upon atmospheric entry.
Meteors of the Orionid meteor shower streak as they cross through the milkyway in the mountainous area of Tannourine in northern Lebanon, on October 3, 2021.
Orionid Meteor Shower a Product of Halley's Comet
The Orionid meteor shower is closely linked to Halley's Comet, which orbits the sun every 76 years. It was last visible in 1986 and is set to return in 2061. This year marks the halfway point for Halley's Comet as it reaches aphelion, its farthest distance from the Sun, which begins on December 9, 2023.
Halley's Comet is famous for being the first comet associated with repeat visits to our skies, with records dating back over 2,000 years. The comet is named after Edmond Halley, who predicted its return and is classified as a short-period comet with an orbit of less than 200 years.
In 1705, Halley used Newton's theories to predict its return, making it history's first known periodic comet. This comet was even depicted in the Bayeux tapestry, which chronicled the Battle of Hastings in 1066.
When Halley returns to the inner Solar System, it releases debris, resulting in two annual meteor showers: the Eta Aquarids in May and the Orionids in October. Halley's Comet is about 9.3 by 5 miles (15 kilometers by 8 kilometers) in size and is one of the least reflective objects in the solar system, with an albedo of 0.03, reflecting only 3% of incoming light.
Its orbit is inclined at 18 degrees to Earth's orbit, moving in a retrograde motion opposite to Earth's direction. The average orbit period is 76 years, but it varies due to gravitational effects from planets.
Halley has made its closest approach to Earth in 837; and during its 1986 appearance, it was slightly brighter than Polaris, the North Star. Each orbit causes Halley to lose material, and it's estimated to complete about 1,000 orbits before aging and possibly dissipating into dust.
Tips To See the Orionid Meteor Shower
To view the Orionid meteor shower effectively, one should consider the presence of a near-First Quarter Moon, which will illuminate the pre-midnight sky. The best viewing opportunity for the Orionids is in the pre-dawn hours, away from light pollution, as the moon will set during the early hours.
If planning to observe the Orionids, prepare with snacks, drinks, a reclining chair, and warm clothing. Avoid using binoculars or a telescope, as they limit your field of vision. Smartphone use should also be avoided due to its disruptive white light. Keep your gaze on the night sky, as shooting stars can appear anywhere, and take regular breaks.
Additionally, another recommended method for observing the Orionids is to set up a DSLR or mirrorless camera in your backyard, capturing multiple 30-second exposures. Use a wide-angle lens, a tripod, an aperture setting of around f/2.8, and ISO 800.
Adjust the camera to infinity focus and experiment with manual settings to capture stunning night sky images. Leave the camera in continuous mode to take hundreds of photos, checking them the following day for any images of shooting stars.
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