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I was using SkyMap Pro recently to get an idea of how high in the sky Comet C/2012 S1 ISON will be in the fall.
I noted that Mars and Comet C/2012 S1 ISON will be with two degrees of each other in the morning sky in September 2013 and within one degree of each other in October 2013. So using SkyMap Pro I generated the following sky maps as shown below as they may be helpful to observers attempting to locate the comet.
In addition I have included tables listing the phases of the Moon for September and October.
The first map shows the track of Mars and Comet C/2012 S1 ISON from September 15th through October 15th. Both Mars and Comet C/2012 S1 ISON are in the constellation of Cancer in September and are in Leo in October.
On the maps there are track marks for every five days. The track marks on the left are Comet C/2012 S1 ISON while the tracks on the right are Mars. You will note that over time they are getting closer to each other:
The second map below shows the approximate 4 degree field of view through my TMB 105mm with a TMB 40mm 2" Paragon of Mars and Comet C/2012 S1 ISON on September 15th. It indicates that both Mars and the comet should fit into the same field of view. The blue-green color of the comet could make for an interesting contrast with the orange and brown colors of Mars.
However at this point it appears that the comet will develop more slowly in the autumn sky than originally thought, and may not reach naked eye visibility until November.
On the other hand if you have access to dark skies and a large aperture telescope or do astrophotography you may be able to use Mars as a guide to locating the comet.
September Phases of the Moon:
New Moon: 11:36 05-Sep-2013
First quarter: 17:08 12-Sep-2013
Full Moon: 11:13 19-Sep-2013
Last quarter: 03:55 27-Sep-2013
October Phases of the Moon:
New Moon: 00:34 05-Oct-2013
First quarter: 23:02 11-Oct-2013
Full Moon: 23:37 18-Oct-2013
Last quarter: 23:40 26-Oct-2013
On October 12th, 2013 at 4:32 UT there will be a rare triple shadow event across Jupiter lasting 65 minutes. As shown below in the SkyMap Pro map the moons casting the shadows on Jupiter are Io, Europa, and Callisto. Callisto will be casting its shadow on the South Polar Region of Jupiter.
This event will be visible mostly for observers in Europe and the Northeastern Eastern United States. While Jupiter will be low in the sky for observers in the Eastern United States it may still be worth while to observe it. This is because sometimes the seeing conditions can be better than expected. There have been times I have set up my telescope to observe a celestial event and the seeing did not seem like it would be very good. Still I ended up seeing some detail that I would not have otherwise seen if I did not set up the telescope.
For example during the Venus transit across the Sun on June 8th, 2004, Venus and the Sun were only around ten degrees in elevation when I began obsering them. Still, I saw far more detail than I expected.
While I was researching and writing the article on The Bondís: Pioneers of American Astronomy I came across a sketch made by George Bond showing three shadow transits on Jupiter on January 28th, 1848 using the 15" Great Refractor as shown below. In his sketch he recorded the shadow of Io and Ganymede, and Ganymede itself:
I got up early to observe Jupiter and Mars in the morning sky. It was clear and cool. The Harvest Moon was bright in the western sky, while bright Jupiter in Gemini changed the outline of the constellation. Ursa Major was low in the northern sky, and Cassiopeia was high overhead. In the southern sky Orion and Sirius were bright. It was nice to see some olds friends again.
One of the things that I enjoy about observing sessions is listening to the sounds of nature. For example down near a river I could hear some geese as they honked a few times before settling down in the cool night air, and later heard a small animal who was foraging for a snack near some trees. I listened also to overripe fruit falling to the ground from some other trees.
I set up the TMB 105mm (4.1") f/6.2 on its alt-az mount and took a quick look at M42 using a low power eyepiece. Even with the bright moonlight I could see some of the nebulosity in the Orion Nebula.
I then inserted the Baader binocular viewer with the 1.7x corrector, with a Baader Planetarium Moon & Skyglow filter, and TMB Monocentric eyepieces. and began observing Jupiter. The seeing was variable, sometimes fair, and other times good. Magnifications varied from 123x - 185x.
Some of the detail that I noted included the South Polar Region, which appeared brown in color, and the South Tropical Zone appeared white in color. The South Equatorial Belt (SEB) was reddish brown in color. The Equatorial Zone was white in color.
The North Equatorial Belt (NEB) was reddish brown in color, although it appeared to be more reddish brown in color than the SEB did. However, the SEB appeared wider than the NEB. Also there appeared to be rifts in the NEB.
The North Tropical Zone appeared white in color, while the South Polar Region which appeared gray in color.
After I finished observing Jupiter I noted that Mars was above the trees. Its orange color reminded me of Betelgeuse in Orion. Through the telescope the seeing was not as good as it was for Jupiter. Still I was able to make out it's gibbous shape and it was nice to observe it again.
Also as Mars is near Comet C/2012 S1 ISON in the sky I will be able to Mars it to locate the comet once the Moon is near its new phase.