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Comet Halley is three billion miles from Earth right now — farther than Neptune, the most distant of the Sun’s major planets. Yet it’s sending us a reminder of its presence the next few nights: the Orionid meteor shower.
Halley passes close to the Sun every 75 years or so. The Sun’s heat vaporizes some of the comet’s ice, releasing small bits of rock and dirt into space. Over time, these particles spread out along the comet’s orbit. Earth intersects this path twice a year — in May and October. When it does so, some of the particles ram into the atmosphere at speeds of up to 150,000 miles per hour. They quickly vaporize, forming the glowing streaks known as meteors.
Just to confuse the issue, though, a meteor shower isn’t named for its parent comet. Instead, it’s named for the point in the sky from which the meteors appear to fall. In this case, it’s around the “club” held by Orion, the hunter, so the shower is known as the Orionids.
You don’t have to look at that point to see the meteors, though. They can flash anywhere in the sky. But the shower is best viewed after Orion climbs into good view in the east, in the wee hours of the morning.
The shower is expected to peak before dawn on Thursday, with rates of around a dozen meteors per hour. But the Orionids tend to be spread out a bit, so you can generally see almost as many meteors for a day or two before and after the shower’s peak — brief reminders of a distant comet.
Script by Damond Benningfield, Copyright 2015