Professor Don Pollacco, Physics, University of Warwick, said:

“As comets orbit the Sun, the action of the energy evaporates material from the cometary nucleus, which we see as a comet’s tail. The gas and dust created stay in the comet orbit, even long after the comet has moved along its orbit. If the Earth passes through the comet’s orbit any material deposited by the comet could become meteors or shooting stars in the sky. These bodies are usually the size of dust particles but when they fall into the Earth’s atmosphere, they are traveling so fast that they are vapourised. Along the path that the dust particle travels, the gas molecules are superheated and give out light – this is a meteor. We don’t actually see the dust, instead its vapourised effects on the molecules. As the Earth is crossing the comet orbit, the meteors seem to be coming from the same direction – called the radiant.

“The Earth passes through a number of comet orbits every year and at these times we see an increase in meteor activity, depending on the density of dust previously ejected from the comet. The Eta Aquarid meteor shower, so called because the radiant is in the constellation of Aquarius, occurs when the Earth crosses through the orbit of a comet called Halley. These meteors are best seen from the southern hemisphere where the radiant in Aquarius is better seen. From the UK you might expect to see, maybe, 10 meteors an hour in clear, dark conditions.”