October and November 2015
Well, I can’t pretend that it hasn’t been a disappointing period as far as planetary observation has been concerned. While there has been perhaps a couple of short patches of good weather there has been no bright evening planets to tempt people outside and, while there has been a decent line-up of planets in the morning sky, continually getting up at 4 am to peek out the window and decide if it is worth going outside has been something of a trial. Add into the mix a series of bad storms over the UK and the very-nearly permanent presence of the Jetstream distorting the upper air through which we try and observe and it came as no surprise that there were very few observations reported this time around.
In fact, my first reported observation for the period did not come until the 26th of October when Paul Crossland was able to see and photograph the close conjunctions of Venus, Jupiter and Mars near by the star sigma Leonis in the pre-dawn sky. He used a 300mm lens on his DSLR camera to capture his image and framed the planets around the TV aerial on a nearby rooftop in order to bring out just how close together this little cluster of planets seemed to be. On that same morning John and Ann Tipping took advantage of the same window of good weather to take a wider view of the planetary grouping but managed to include Mercury as a tiny spark, very low and only just visible in the south-east in an area of dispersed aircraft contrails which were bottom-lit by the Sun, itself just below the horizon.
On the 29th
, during one of my own early morning checks of the weather, there was a small gap in which I could see the clustering of Jupiter above Venus, the pair a little to the west of Mars. This was at 0437 UT when then the trio were suddenly joined by another bright spot of light, easily brighter than Venus and moving slowly past and above Denbola in Leo. Within a few seconds this new ‘star’ faded down to being barely visible and I thought I had probably seen an ‘Iridium Flare’; the point on the ground when reflected sunlight from the solar-panels of an Iridium communications satellite sweeps over you. A little research on the Heavens Above website revealed that in fact I had seen sunlight from below the horizon glinting on the remains of a satellite called Adios-II. This was apparently an Earth-imaging satellite launched from Japan 2002. It lost a solar-panel in 2003, possibly due to an impact with unknown space debris, and was a multi-million yen loss; odd to see a ghost of it on an early morning in October. Needless to say the clouds closed in and I saw no more.
By coincidence my checking of the Heavens Above website told me that there would be an actual Iridium Flare event on the evening of the same day. I managed to persuade my wife that this would be worth watching as the satellite would briefly shine at a search-light like magnitude of -8.0. We stood outside at the appointed time to see a thin veil of cloud covering the whole sky. Nonetheless at exactly the correct time, as predicted, a star of light managed to pierce the cloud in exactly the right place. My wife’s comment on this event? “Was that it?”
Moving swiftly on. The night of the 31st of October into the 1st of November was forecast to be clear and, just as importantly, the upper winds where light giving steady seeing conditions throughout the depth of the atmosphere. If you are interested you can check these weather conditions for your own local area in the UK by visiting this website:-
The website will give you an estimate for total cloud cover and for ‘seeing’ conditions for periods throughout the night and is very useful. Martin Lewis capitalised on the steady seeing by imaging Uranus and surrounding moons around 2313ut on the 31st. His outstanding image was taken with a large Dobsonian telescope on an equatorial platform and with an ASI224 colour camera and a filter than allows deep-red and infra-red light to reach the sensor. Despite being a colour camera this ASI is very sensitive to IR light and captured faint banding and obvious brightening of the north-polar regions on Uranus; something that is only really possible in good seeing conditions.
I had tried several times to get a decent set of images of the ice-giants, Uranus and Neptune, but had always been defeated by poor seeing. The general advice given for this work is that if the seeing isn’t good then don’t waste your sleep! I tried again on the evening of the 1st of November with my 10 inch (250mm) aperture Newtonian telescope and managed, at last, to capture some detail on Uranus and a decent disc for Neptune with little Triton making an appearance in that image. While not as clear or as expertly-done as Martin’s work, polar brightening and, perhaps, very faint banding can be seen so I consider that some part of a success. I also used an ASI224 colour camera and an IR filter; this latter seems to be necessary for capturing detail on either of the ice giants as nothing is recorded in visible-light images other than colour information.
The following morning I hoped to capture Jupiter, Mars and Venus; following Venus into daylight, if necessary, to make the most of available observing time. While I was able to capture Jupiter and Mars sadly a bank of thick fog rolled in as I moved the telescope onto Venus so was unable to get any results. Steve Norrie had exactly the same idea and he captured first Jupiter and then Venus, but since he lives around 12 miles from me he suffers under the same weather patterns and was unable to get Mars before also being covered by the fog blanket. Between us we did just manage to capture ‘the set’ of what was on view on the morning of the 2nd of November.
The Jupiter images, taken a matter of a few minutes apart, do not show any startling changes in Jupiter since the last time the section imaged it back in July but some points are evident. A ring of white-oval storms still rotates around the South Polar Region while the South Tropical Zone seems placid with only slight evidence of any South Temperate Belt within it; there are large festoons in the equatorial zone and faint evidence of a darker equatorial band around the equator. The northern belt system above the north equatorial belt (NEB) does seem more complete than before with two distinct belts visible, possibly three as the most northern edges into the North Polar Region. The northern edge of the NEB is still very disturbed with major ‘White Spot’ storm activity biting into it; a yellow or pinkish tinge in the largest storm may be increased activity in White Spot Zulu. It will be interesting to see how both the Great Red Spot and Oval BA have fared when higher resolution images are available later in the apparition.
Mars was a challenging target. At just over 4 arc-seconds in apparent size it was barely larger than Uranus to the eye, however being much brighter it could take more magnification when imaging. While darker albedo features are discernible in the image I can’t really tie them in with any features on view at the time the picture was taken. Mars too, will improve in size as it moves towards opposition in May 2016. Steve caught Venus in both IRGB and RGB filtered imaging runs and the phase, at very nearly 50%, is clear. We both hope to get more Venus images in November when the phase has increased making capture of cloud features (hopefully) a little easier.