Merging the Telescope World with the Real World


From left to right: Moon, Callisto, Io, Europa, Jupiter, Ganymede. Click to see the full-sized image.

As mentioned previously, I took several different types of photographs the night of Sunday, May 7th, when the Moon and Jupiter were close.  One of these perspectives was by mounting my digital camera on a tripod to get a wide-field view of the Moon and Jupiter together.  I took many images with different exposures and ISO settings.  Here is one such raw image:

Here, you see an overexposed Moon along with Jupiter.  This shows the distance between the two at 05/07/2017 21:20 Central Time, approximately.

The important aspect of this picture is that it captures all of Jupiter’s Galilean moons.  If you click on the image, you will easily see three of them – Io, Europa, and Ganymede.  Callisto is there, or at least, is there in the raw TIFF image.  You will have to take my word for it that Callisto is there, just very faint.

How do I know which moons are which?  The easy way I follow is to use this Jupiter moon tracker, plugging in times and dates when I take my pictures.  If you enter the time stamp I wrote above, you will get this:

Now while my original source image is nice, I knew I could improve upon it with other images taken that same night at my telescope.  After accentuating Callisto’s brightness a little so we can see it, I used Photoshop Elements to carefully cut out Jupiter and its four moons.  I then overlayed these into a properly-exposed wide-field Moon image.

Next, I wanted to get a good Jupiter into the picture, since the planet itself is overexposed in all my tripod images.  I created the following image from stacked video at my 10″ Dobsonian:

I will shrink this good Jupiter to overlay into the main picture were the bright overexposed Jupiter resides.  But I also wanted to get the planet’s angle right relative to the moons.  So I imported as a temporary layer this other picture I took on Sunday that I previously wrote about:

This “moon” image is the perfect gauge, first to align with the native orientation of Io and Europa in the main image, and then to align the good Jupiter with the moon image Jupiter.  With the proper angle, I then overlayed this good Jupiter on top of the overexposed Jupiter, shrinking it a bit to compensate for the over-brightness of the original.

The final result is the image at the top of this post.

As a final perspective, I used the telescope Moon image I posted earlier and overlayed it in, and then moved the Jupiter system next to the Moon.  This gives you an idea of how wide an area Jupiter and the Galilean moons take up in reference to our Moon:

Composite image of Moon, Jupiter, and the Galilean Moons.

That’s all for now. I am hoping with the Moon waning over the next week that I will be able to take more constellation pictures, and possibly a few deep sky objects.

Paul

Paul

I write frequently about astrophotography, technology advice, and my other interests like science fiction. I have over 30 years of experience in computer programming, information technology, and project management.

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