This weekend, from Saturday night into Sunday morning (10/21-10/22), you may observe the annual Orionid meteor showers streaking across the sky. Dozens of meteors will scorch the sky every hour.(Of course, the sky must be clear and dark, which, unfortunately, is not for me.) Fortunately, the moon is only in its crescent phase, so its light does not interfere with observing the meteor shower. The Orionid meteor shower happens every year in late October when Earth cross through debris left by Halley’s comet. Halley’s comet last passed through our solar system in 1986, and will not come back until 2061. When Halley’s comet neared the Sun, the heat melted the comet to form gas and dust. Though the comet leaves the solar system, that gas and debris continues to orbit the Sun. Most of the particles that form meteors are only the size of a few grains of sand, but comets have high kinetic energy as they hit Earth’s atmosphere— over 50,000 miles per hour! As the grains, or debris meteoroids, contact Earth’s atmosphere, they ionize molecules in the atmosphere, forming a bright trail across the sky known as a meteor or shooting star. Small meteoroids burn up in Earth’s atmosphere. A meteoroid must be bigger than the size of your fist to survive and hit Earth’s surface. Meteorites are usually found in deserts or Antarctica, where their black coloration stick out easily against the ground. Most meteorites land in the ocean, so no harm done there! In fact, 800 meteorites heavier than 100 grams strike the Earth every day; during meteor showers the frequency is higher.
- Why “Orionid”? The meteors seem to intersect at Betelgeuse in the Orion constellation (but it’s just an optical illusion).
- The Orionids historically have only produced 20 meteors at its peak, but in the last decade, scientists have observed more than 60 meteors per hour!
- Meteors travel in space; meteoroids fall though the atmosphere; meteorites strike the surface
- Did you know Halley never saw Halley’s comet? Halley suggested that the comet spotted in 1682 was the same one in 1531 and 1607. Halley’s observations led to the conclusion that comets orbit the sun. In 1705, he predicted the comet would appear in 1758, but died before he actually saw the comet.
- Aside from Orionids, the other annual meteor shower is the Eta Aquarids that peaks early May.
Pereira, Pablo. “Meteor Shower Created by Halley’s Comet Peaks Tonight.” FOX News. FOX News, 20 Oct 2012. Web. 21 Oct 2012.