This debris rams into the upper atmosphere at speeds of 60 kilometres per second causing the air to ionise and shed bright streaks of light as the grain sized particles vapourise. This is what we see as meteors or shooting stars.

This meteor shower has been observed for a long time and is known as the Perseid Meteor Shower or Dmugh ta’ San Lawrenz in Maltese tradition. The point in the sky – the Radiant – where these meteors, if traced back seem to originate in the constellation of Perseus and hence the name of the meteor shower, the Perseids.

This year is a favourable year for this meteor shower. The light from a waning crescent moon rising at 0.43am will not interfere much with the meteor shower. Every12 years this shower becomes stronger than average and 2004 is one of the favoured years.

This is due to the effect the planet Jupiter, which orbits the sun every 12 years, has on the meteor stream. The passage of the massive planet pulls the meteoroids closer to the sun and the core of the stream may be shifted closer to Earth resulting in more meteors being observed. Predictions cannot be accurate but the normal rate of the meteors from midnight to dawn is 60 per hour and hopefully this year would be more.

Watching the meteors does not require any equipment, only dark clear skies. Before midnight when the radiant is still low in the northeast the meteors enter the upper atmosphere at a low angle and few are visible. As night advances the radiant rises higher in the sky and meteors arrive nearly straight down, so one can see a larger number.

The Astronomical Society of Malta invites all to join its members and observe this meteor shower from L- Ahrax tal-Mellieha, next to the chapel, from 11pm onwards tonight. A lecture will given to those present at 11pm to introduce the night sky and explain what is expected to be seen. Telescopes will also be set up for public use by society members.

The Astronomical Society of Malta website address is www.maltastro.org