Orionid meteors streak via the starry sky over Big Bend National Park in Texas, in this composite of 4 photographs taken by astrophotographer Sergio Garcia Rill in October 2017. (Image credit score: Sergio Garcia Rill)On an evening this previous summer season, quickly after sundown, various folks gathered at a little-league discipline, not removed from my dwelling, eagerly awaiting dusk and the looks of the celebrities. We had additionally gathered there as a result of there wasn’t a lot in the way in which of sunshine air pollution and we had been afforded a transparent and unobstructed view towards the northwest. As the sky darkened, we lastly might see it: Comet NEOWISE, displaying a stunning, curved tail. “Not a bad show, considering we’re looking at a cosmic litterbug,” I stated to the coterie of comet gazers. “Really, what we’re looking at is a piece of garbage out in space; think of that beautiful tail as ‘cosmic litter’; little pieces of dust and grit left behind by NEOWISE, all cluttering up the solar system.” If you step exterior earlier than daybreak through the subsequent week or so, you would possibly strive to catch a view of cosmic litter that has been left behind in area by an much more well-known comet: Halley’s. We name that cosmic litter the Orionid meteor shower. And 2020 will likely be a wonderful 12 months to search for them, because the moon will likely be a slender crescent, 4 days previous new part and can have set earlier than 9:30 p.m. native time on the evening of their peak exercise, and won’t pose any hindrance by any means to potential meteor observers.Related: How to see the perfect meteor showers of 2020 If the December Geminids and August Perseids might be thought of rating because the “first string” among the many annual meteor showers by way of brightness and reliability, then the Orionids are on the junior varsity. This 12 months they’re scheduled to attain their most earlier than dawn on Wednesday morning (Oct. 21). The title “Orionid” comes from the truth that the radiant — that spot on the sky from the place the meteors seem to fan out from — is simply above Orion’s second brightest star, ruddy Betelgeuse. Currently, the Orion constellation seems forward of us in our journey across the solar and has not utterly risen above the japanese horizon till after 11 p.m. native daylight time. At its greatest a number of hours later, at round 5 a.m., Orion will likely be highest within the sky towards the south.Skywatchers can begin on the lookout for Orion low within the japanese sky earlier than daybreak on any morning across the peak, Oct. 20-21. The setup is seen right here from mid-northern latitudes. Even although the radiant, or level of origin of the meteors is in Orion, meteors can seem removed from the constellation. (Image credit score: Starry Night software program)But to see the best variety of meteors, do not look within the course of the radiant, however reasonably about 30 levels from it, within the course of the purpose straight overhead (the zenith). Your clenched fist held at arm’s size is roughly equal to 10 levels vast, so trying “three fists” up from Betelgeuse will likely be the place to focus your view. Best instances to watch
Orionid visibility extends from Oct. 16 to Oct. 26, with peak exercise of maybe 15 to 30 meteors per hour approaching the morning of Oct. 21. Step exterior earlier than dawn on any of those mornings and when you catch sight of a meteor, there’s a few 75% likelihood that it possible is a byproduct of Halley’s Comet. The final Orionid stragglers often seem someday in early to mid-November. The greatest time to watch begins from about 1 or 2 a.m. native daylight time till the primary mild of daybreak (at round 5:45 a.m.), when Orion stands highest above the southern horizon. The greater within the sky Orion is, the extra meteors seem all around the sky. The Orionids are one in every of only a handful of identified meteor showers that may be noticed equally properly from each the Northern and Southern Hemispheres. Orionid meteors are usually dim and never properly seen from city areas, so it is instructed that you simply discover a secure rural location to see the perfect Orionid exercise. An Orionid meteor passes over the Atlantic Ocean close to the New Jersey coast simply earlier than dawn on Oct. 21, 2017. (Image credit score: Jeff Berkes)”They are easily identified … from their speed,” authors David Levy and Stephen Edberg wrote of their guide, “Observe Meteors: The Association of Lunar and Planetary Observers Meteor Observer’s Guide” (Astronomical League, 1986). “At 66 kilometers (41 miles) per second, they appear as fast streaks, faster by a hair than their sisters, the Eta Aquarids of May. And like the Eta Aquarids, the brightest family members tend to leave long-lasting trains. Fireballs are possible three days after maximum.” Undoubtedly this is linked in a roundabout way to the make-up of Halley’s Comet. Halley’s legacyComets are the leftovers of the earliest days of the photo voltaic system, the odd bits and items of easy gases — methane, ammonia, carbon dioxide and water vapor — that went unused when the solar and planets got here into their current kind. Meteoroids which might be launched into area out of this cometary particles are the remnants of a comet’s nucleus. All comets finally disintegrate into meteor swarms and Halley’s is properly into that course of at this time. These tiny particles — largely ranging in measurement from mud to sand grains — stay alongside the unique comet’s orbit, making a “river of rubble” in area. In the case of Halley’s Comet, its soiled path of particles has been distributed roughly uniformly all alongside its complete orbit. When these tiny bits of comet collide with Earth, friction with our environment raises them to white warmth and produces the impact popularly referred to as “shooting stars.” An picture of Halley’s Comet taken in 1986. (Image credit score: NASA)And Halley’s Comet has left a legacy that’s seen to us within the type of not only one, however two annual meteor showers. This is as a result of its orbit carefully approaches the Earth’s orbit at two totally different locations. One intersection level (alluded to by Levy and Edberg) is within the early a part of May, producing a meteor show often called the Eta Aquarids. The different level comes proper now, within the center to latter a part of October, producing the Orionids. At this second in time, Halley itself is nearing the far finish of its lengthy elliptical path across the solar, out past the orbit of Neptune. Its final go to via the internal photo voltaic system was within the winter of 1986. It will arrive at aphelion — its farthest level from the solar, 3.28 billion miles (5.28 billion km) — in early December 2023. Thereafter, it would start its lengthy journey again towards the solar, due to return within the midsummer of 2061. If you had been born any time after 1983, you in all probability have a greater than 50-50 likelihood to catch it on its subsequent return. But for people like myself — who will in all probability not be round when it returns — the Orionids will give us an opportunity to at the least catch a view of a number of the cosmic particles Halley has left behind in its wake.Joe Rao serves as an teacher and visitor lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History journal, the Farmers’ Almanac and different publications. Follow us on Twitter @Spacedotcom and on Facebook.
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