Chart (9pm on the 15th May) produced using the Stellarium software package
Three planets feature this month
May provides us with progressively longer nights and cooling weather, and the bright stars of summer start to disappear towards the west after sunset. The more sparse skies of autumn replace them in the east, and this year the lack of bright stars is offset by the sight of three planets.
Bright stars this month include white Sirius, the brightest star in the whole sky, low in the west, blue-white Canopus higher up, yellow Alpha Cenaturi and the Southern Cross high overhead, and orange Arcturus low in the north east.
The bright winter Milky Way is starting to reappear low in the east after the sky turns fully dark, and will become a major feature during the winter months to come.
Jupiter shines, Mars and Saturn return
There are three bright planets visible in our evening skies during May, and are the highlight for the month. The brightest of these is the giant planet Jupiter, which shines towards the north after sunset.
Jupiter is unmistakable, being the brightest object in that part of the sky and was described in detail last month. Jupiter will continue to be visible in our evening skies for a number of months to come.
Attached to this article is a picture of Jupiter taken by the author from his back garden in Bungendore on the 14th April. The picture shows the detail that can be seen under our dark rural skies with a backyard telescope.
The large red oval near the middle is the Great Red Spot, a hurricane-like storm, three times the size of Earth which has been raging on Jupiter for at least the last three hundred years. The way in which the spot disturbs the clouds around it can be seen, and there is a large amount of turbulence following behind it.
The small dark spot towards the top of Jupiter is actually one of its moons, Ganymede, which was passing in front of Jupiter at the time. Ganymede is a lot darker than the cloud tops of Jupiter, so comes out as a dark grey spot. Another of its moons, Europa, is visible as the bright star to the left of the planet itself.
The details on Jupiter are dynamic and change all the time, pictures taken the next day would show how some of these features have moved and changed shape. Jupiter suprises us sometimes and Astronomers keep a close eye on the cloud patterns to understand the weather on that giant world.
Also visible this month is the red planet Mars, returning to our evening skies after being absent for the last year or so. Mars is also unmistakable rising in the east as a bright reddish coloured ‘star’.
Mars is seen at its best on the 22nd May, and is only seen at its best once every 2 years and 2 months. This is because of the way in which the orbits of Mars and the Earth line up, and it was back in April 2014 that we last had a close-up look at it.
Take this opportunity to go out and have a look for yourself. Binoculars will show Mars’ characteristic red colour and small telescopes will reveal a polar cap and dark surface features. Larger telescopes will show clouds, fog and frost. Although completely inhostpitable to us, Mars is the most Earth-like of the other Solar System planets.
The third planet this month is the ringed planet Saturn, found close to Mars in the eastern sky after sunset, but is identified by its more yellow colour and is much fainter than Mars.
Saturn is a spectacular sight through a small telescope and is something that once seen, is never forgotten. Saturn is at its best on June 2nd, and will be described in detail next month.
The Moon is new on the 7th May, at first quarter (half) phase on the 14th, full on the 22nd and at third quarter phase on the 30th.
Finally, go check Dr David Weldrake’s website.