Gas Giants in September 2021

 

Jupiter 08-09-2021, Meade 127mm Apo refractor-QHY5L-11c camera - 3minute avi clip stacked. Credit: Pip Stakkert.

Saturn 08-09-2021, Meade 127mm Apo refractor-QHY5L-11c camera - 9 minute avi clip stacked. Credit: Pip Stakkert.

" The weather forecast for the night of the 8th of September was not good but the weather was predicted to deteriorate in the nights following. We therefore decided to give imaging the gas giant planets, Jupiter and Saturn, a go anyway. 

The planets remain low on our southern horizon and there was also a hint of high level cloud both of which made obtaining sharp images problematic. Saturn being the lower of the two planets was wobbling about all over the place and was difficult to focus. The day had been quite hot in Lowestoft and residual heat radiating from adjoining house roofs exacerbated the atmospheric problems. The difference in image quality between Jupiter and Saturn is clear. Jupiter being much closer, bigger and at a greater declination all go to making for a sharper more detailed image.  Over the next few years the planets will get higher in the sky in the Northern Hemisphere.

If you look closely at the image of Jupiter you can just make out the Great Red Spot towards the bottom of the sphere at about '5 o clock' on the planet's limb. You can also see that Jupiter is not a perfect sphere, having a greater diameter measured at the equator than through the poles. Jupiter is an 'oblate spheroid'. This is because Jupiter is made from primarily gas and is rotating at considerable speed. The Jupiter day is only 10 hours long!  Centrifugal force acts upon the gas to increase the diameter at the equator where the speed is maximised." - Kurt Thrust current Director of the Jodrell Plank Observatory.