The spectacular Orionids meteor shower will come to its peak on October 21 in the northern hemishpere. The best time to observe the phenomenon is after midnight and before dawn, provided however that the sky is clear from clouds. Luckily this year, the thin lunar crescent will allow observers to fully enjoy it. The Orionids are debris left behind by comet Halley and the phenomenon occurs every year from early October until early November. About 20 to 25 meteors per hour enter the earth's atmosphere and vaporize at some 100 kilometres above the Earth’s surface. The meteors were named Orionids because they seem to emerge from the Orion constellation.