Last month’s transit of Venus across the surface of the sun was certainly an event which was not to be missed. Millions of people watched it from around the world, including Malta.

The Astronomical Society set up its telescopes in two locations, Marsascala and St Julian’s, on this special occasion. The accompanying picture was shot by Karl Borg, who managed to capture Venus as the black dot on the sun’s face exactly as the sun was rising over the sea.

Many people around the world turned their attention to the sky to make sure they saw the planet Venus passing directly between the Sun and Earth – an event that will not occur again for another 105 years.

British astronomer Sir Edmond Halley realised that by observing such events from widely spaced locations on Earth, it should be possible to accurately triangulate the distance from Earth to Venus.

Halley is best known for having predicted the return of the comet that bears his name. Halley’s Comet is visible every 75-76 years – the last time was February 1986; the next time will be July 2061.

Maltese artist Giuseppe Calì had beautifully depicted the 1910 appearance of Halley’s Comet over the Grand Harbour in one ofhis paintings.

Venus transits happen in pairs eight years apart, but with more than a century between cycles. During the event, Venus appears as a small, dark round spot moving across the face of the sun.

Since then, Venus has reappeared as the Morning Star, low in the east before sunrise. Do not confuse it with Jupiter to its upper right.

An interesting event this month involving Jupiter will be its occultation on July 15. At 3.10 a.m. the moon, on its route circling the Earth, will pass in front of Jupiter and it will disappear, then reappearing on the other edge of the moon an hour later. One will be able to easily see this event with the naked eye or better still a simple pair of binoculars.

Astronomical events this month

Tomorrow: Jupiter close to the planet Venus (morning sky).
Tuesday: Full moon
July 9: Venus to the upper right of the star Aldebaran in Taurus (morning sky).
July 11: Last quarter moon
July 15: Occultation of Jupiter and its moons by the moon with the Pleiades, the Hyades and Venus nearby at 3.10 a.m.
July 16: The moon close to Venus.
July 19: New moon
July 24: The moon close to the planet Mars.
July 25: The moon to the lower left of Saturn and to the star Spica in Virgo.
July 26: First quarter moon

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Architect Alexei Pace is president of the Astronomical Society of Malta.