Definition | Lyrides | Futura Sciences

The Lyrids is the name given to a meteor swarm active every year between April 16 and 25. This is the first rain ofshooting Stars significant of spring. It is also one of the oldest known (the Lyrids are mentioned in the Chinese chronicles in 687 BCE).

On April 22, at its maximum, the hourly rate can reach 20 meteors when the constellation de la Lyre – near which is the radiant (between the brilliant Vegeta and Hercules' knee, nicknamed the Kneeling) – is highest in the sky. In the past, bursts of activity surprised observers several times: more than 100 meteors per hour were visible in 1803, 1862, 1922, 1945 and 1982. For specialists, they occur on average every 60 years. The next one is announced for 2042.

How to properly observe the rain of shooting stars of the Lyrids?

The micrometeorites that make up the Lyrids enter theatmosphere earthly to one speed average of 50 km / s. About a quarter of them leave in their wake beautiful persistent streaks visible for several seconds.

Like the other meteoritic swarms of the year, the Lyrids are fed by debris left by a comet. In their cases, it is C / 1861 G1 Thatcher, discovered in 1861 shortly before its last perihelion. It was then 50 million kilometers from the Earth. Thestar come back to visit the Solar system internal every 415 years.

The peak of Lyrid activity is generally April 22 but it is possible that the previous and following nights, we can see between 10 and 20 meteors per hour. The exact moment of the maximum remains difficult to predict. To make the most of this celestial spectacle, it is important to favor observation sites spared (as much as possible) by the light pollution. Of course, the presence of the Moon – variable depending on the year – reduces the visibility of the meteor salvo.