As night settles in this evening, our planet silently plunges through the orbit of comet Swift-Tuttle, encountering debris left over by the comet each time it approaches the sun, every 130 years.

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

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

Watching the meteors does not require any equipment only dark 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 we can see a larger number. The Earth’s rotation changes direction after midnight facing the on-coming meteors and thus increasing the velocity with which the meteors enter the atmosphere making them more visible.

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 9.30pm onwards. A computer presentation will also be running continuously from 9.30pm. The planet Jupiter, and the moon, are also visible and well placed in the sky for observation. Telescopes will also be set up by society members for public use.

For all those wishing to get acquainted with the night sky and get to know about the wonders that the sky has to offer, a presentation by Prof. F. Ventura and Mr Leonard Ellul Mercer, followed by an observing session will be held on Sunday 16 August 8.30pm at the Greek Theatre, Gnien L-Gharusa Tal-Mosta near MCAST, Targa Gap Mosta. The Astronomical Society of Malta web site www.maltastro.org.

The Astronomical Society of Malta