Gazing at the southern hemisphere’s beautiful night sky is always worthwhile. But when your view is "interrupted" every few minutes by bright, fast-moving streaks of light, the level of enjoyment and excitement is taken to a whole new level. That’s why, if it is clear after dark later this week, I plan to head to Otago Peninsula to observe the peak of one of the best meteor showers this year.
A meteor is the astronomical name for a piece of cosmic debris which flashes brightly for a few seconds as it burns up high in the Earth’s atmosphere. Because the material (mostly tiny grains of ice or dust) is moving very fast relative to the Earth, it heats up and eventually vapourises as it enters our atmosphere. On any clear moonless night you see several meteor streaks every hour. At certain times of year, usually when our planet crosses the orbit of a comet, the increased density of debris means we see many more meteors than usual. We call this a meteor shower.
Later this week, Earth is crossing the path of Halley’s comet which will give rise to a meteor shower where up to 30 meteors will be visible every hour. The comet itself is still more than 5 billion kilometres away from us in the outer solar system. However, as comets orbit the sun they leave behind a trail of dust and gas in their wake. Because of the geometry of Earth’s own orbit in relation to that of the comet, the meteor shower will appear to come from the direction of the constellation Orion, which is why this shower is called the Orionids.
The best time to look out for Orionid meteors is after midnight from October 20 to October 23. Moonlight won’t be a problem as it will be a waning crescent, rising quite late in the night. While the meteors seem to come from the general direction of Orion, they will be visible across the whole sky. You don’t need a telescope or binoculars to enjoy this event. Happy meteor hunting!
