Planetary Alignment

I have had a frustrating couple of days because one of the great celestial displays has been denied me, despite my best intentions. For the first time in over a century, four planets in the solar system - Jupiter, Venus, Mercury and Mars - have collected in Y-shaped fashion in one small corner of the sky. The southern display over the east coast of Australia has been especially good because it's late Autumn and the nights are long. Since the display occurs just before dawn, the extra period of dark is a great help. So, too, is the generally crystal clear atmosphere.

Well, that's the theory, but Armidale's weather has deteriorated markedly over the last couple of days. We've had the first blast of winter and, although the days are still quite good at 13C, there is a lot of misty cloud hanging around, especially at around dawn. I'm typing this at nearly 7.30 am and the cloud is slowly clearing to a blue sky - but much too late for planet-gazing and I'm in danger of missing my chance. This is a pity, because the next such display is apparently scheduled for 2056 and my chances of seeing it are slim. I'd be about 111 at he time.

So, I attach a couple of images of what I would have seen with a clear sky. The images were posted on the web by Sydney residents. The first shows Jupiter, Venus and Mercury (the small blob) in V formation. The second adds Mars a fair way below. You can see the glow of dawn in the second and can appreciate the limited opportunity to see the display just as it rotates above the horizon. Both yesterday and today I arose shortly after 5am. Yesterday, I jumped in the car and drove around trying unsuccessfully to find a suitable hole on the clouds Today, I went outdoors and surveyed the cloudy skies before giving the game away.

Postscript: 15 May 2011: The sky cleared tonight and I leapt out of bed at 5am to scan the horizon for this celestial display. It was a beautiful sight and crystal clear - very much like the second of the pictures.
AS