By CLIVE JACKSON
Clive Jackson is the Director of the Astronomical Observatory of Tavira (Sitio do Malhão, Tavira) and the Camera Obscura (next to the Castle in Tavira), specialising in education and public outreach.
WELCOME TO the June night sky. This is the month that has the longest days and shortest nights of the year. This is simply due to the position of the Sun relative to the tilt of the Earth’s axis.
This month, the axis of the Earth is tilted towards the Sun in the northern hemisphere and this allows the Sun to reach its highest position in the sky – this year it occurs on June 20/21, depending on your geographic longitude.
At this time of year we will have more than 15 hours of daylight and only five hours of true darkness with four hours of twilight. The further north you travel, the more extreme this situation becomes with 24 hours of daylight north of the Arctic Circle.
Soon after the sunset, when we look over to the south eastern horizon, the giant planet Jupiter can be seen rising. This planet is in the constellation of Sagittarius and its four large moons can easily be seen through any telescope. Galileo discovered these moons 400 years ago using a tiny telescope he made himself. On June 19 the Moon is just one day past full and will be close to Jupiter.
High up in the evening sky towards the west, you will see the constellation of Leo. This month there are two planets in this area of the heavens.
The brightest of these two is Saturn and it is a yellow colour and shines with a steady light just to the left of the sparkling white star called Regulus. The planet Mars is also in Leo and is approaching Regulus from the right, and by the end of the month Mars is very close to this star. You can see how quickly Mars is moving and every night it will be in a slightly different position.
The word planet means ‘wandering star’ and Mars is wandering very quickly at the moment. On the night of June 7, the Moon will be very close to Mars and on June 8, the Moon will pass by Saturn.
At the end of the month, on the night of June 30 we have the Draconid Meteor shower, so called because the meteors originate from the northern part of the sky in the constellation of Draco.
With luck we shall see one meteor every five minutes, but there is never any guarantee with meteor showers.
The Moon is New on June 3, First Quarter on June 10, Full on June 18 and Last Quarter on June 26.
For more information, please call Clive Jackson on 281 321 754, fax 281 324 688, email [email protected] or visit http://www.cdepa.pt