As Earth ploughs through the central portions of a dust cloud that was once part of the tail of Halley’s comet, meteors will be visible from both the Northern and Southern Hemispheres.
The Orionids are so named because they appear to be coming from the Orion constellation, which is in the southwestern sky if you are in the Northern Hemisphere or the northwestern sky if you are in the Southern Hemisphere. The meteors will appear to emanate from this point and could fly in any direction.
No special equipment is needed to view the meteors, just a warm coat and some patience. You can expect to see up to 20 blazing streaks of light per hour. Meteor showers tend to reward those who spend an hour or more under the stars, so your eyes become well adjusted to the dark, maximising your ability to see even fainter meteors.
In 1705 English astronomer Edmond Halley published the first catalog of the orbits of 24 comets. His calculations showed that comets observed in 1531, 1607, and 1682 had very similar orbits. Halley suggested that they were really one comet that returned approximately every 76 years, and he predicted that comet’s return in 1758. Halley did not live to see his prediction come true (he died in 1742), but the comet was indeed sighted late in 1758, and was named in Halley’s honour.
Dust particles shed during the comet’s slow disintegration over the millennia are distributed along its orbit. The passage of Earth through this debris stream every year is responsible for the Orionid and Eta Aquarid meteor showers in October and May, respectively.
Halley’s Comet is next expected to return to the inner solar system in 2061.