Starwatch: high-speed Leonids can be extremely bright and colourful

One of the year’s major meteor showers takes place this week. The Leonids may not typically produce the most meteors but they can be very bright.

The chart shows the view looking east-north-east from London at midnight as 17 November becomes 18 November. This is the night on which the shower is expected to peak but individual Leonids can be seen any time between 3 November and 2 December.

Although rates can be as low as 15 meteors an hour, the dust grains that form these meteors are extremely fast. They hit our atmosphere at speeds of about 45 miles (70km) a second, and can be extremely bright and colourful.

The dust that becomes these meteors is deposited in space by the comet Tempel-Tuttle. Discovered in 1865, this small comet, whose nucleus is just 3.6km across, circles the sun once every 33 years, constantly replenishing the Leonids dust cloud as it goes. Every 33 years, the Leonids storm, producing thousands of meteors an hour. The next storm is expected around 2035.

The Leonids are much easier to see from the northern hemisphere. From Sydney, Australia, the radiant only rise in the early hours of the morning, leaving not much time before dawn.