Moon and Copernicus Crater

Moon and Copernicus Crater

April 10th, 2022, 9:00 p.m. local time
Conditions: 57 degrees Fahrenheit / 13.9 degrees Celsius; pleasant temperature, brisk wind, rapidly encroaching cloud cover, Waxing Gibbous Moon

Of all of my telescope sessions in memory, this was the most precarious for almost not happening.  I was literally within seconds of not having any material to publish.  And by “material” I mean literally one image that was suitable.  And by “suitable” I mean, in focus.

I knew tonight’s session was risky, as the weather forecast was shown as already “mostly cloudy” an hour prior.  But I had been observing the sky for the past two hours, and the sky was quite clear straight through Sunset.   I also knew the forecast for the coming week is volatile, and this may have been the only brief window for telescopic observation for at least another five days.

I moved my Dobsonian to the back deck around 8:15 p.m.  The sky was still in good shape.  A few wisps of cloud were present, but nothing alarming.  Even to the West, I saw no signs of impending overcast.

I let the primary mirror settle and acclimate to the outside temperature for over 30 minutes, as I normally do.  I then aligned the mirror, as normal, and set up my Q70 eyepiece, and finally started to look for my target…the M37 star cluster in the Constellation Auriga.  Yes, my target was not the Moon, or at least, not my primary target.  Just before the top of the hour, the sky still seemed fine.

But conditions changed horribly rapidly.  Thick clouds approached from behind my roof, encompassing the sky from Southwest to Northwest.  I immediately knew my time was short, and I had to re-prioritize.  Finding star clusters takes time, and attempting to photographing them with a smartphone is even more delicate.  So I did what any quick-thinking amateur astronomy would do: I turned my attention immediately to the Moon.

The Moon, of course, is a far simpler target.  I was able to lock-on and focus within seconds.  I hurriedly attached my phone to the eyepiece while another minute past.  Clouds were already near the Moon.  At this point, I really only had seconds, a half minute tops, before even the Moon would be impossible to photograph.

I managed to take eight image, four with the iPhone’s stock camera app and the other four with NightCap.  For perspective, in a non-pressure session, I easily take at least 30 photos of the Moon, and sometimes more than 60.  For among those dozens, a few should have very good focus with minimal telescope vibration.

The first seven images were in bad or poor focus, I think due to the clouds confusing the camera.  Thankfully, I was able to get in-focus for the final image, which accompanies this article above.  It is nowhere near my best in terms of detail, but is suffices given tonight’s harrowing conditions.

Noteworthy in tonight’s image is the prominence of the Copernicus Crater.  The shadows highlight it well:

This crater is nearly 58 miles (93 km) in diameter.  The name Copernicus is, obviously, one of astronomical history’s most famous.  Why was this crater named after the Polish astronomer?  As explained at Wikipedia:

Like many of the craters on the Moon’s near side, it was given its name by Giovanni Riccioli, whose 1651 nomenclature system has become standardized. Riccioli awarded Copernicus a prominent crater despite the fact that, as an Italian Jesuit, he conformed with church doctrine in publicly opposing Copernicus’s heliocentric system.  Riccioli justified the name by noting that he had symbolically thrown all the heliocentrist astronomers into the Ocean of Storms. However, astronomical historian Ewan Whitaker suspects that the prominence of Copernicus crater is a sign that Riccioli secretly supported the heliocentric system and was ensuring that Nicolaus Copernicus would receive a worthy legacy for future generations.

At this brief narrative’s face value, I tend to believe the latter explanation.  If Riccioli truly wanted to cast Copernicus and his heliocentric heresy into the abyss of History, would he really have named one of the Moon’s most prominent craters after such an egregious offender of Church doctrine?  Immortalizing a heretic’s name upon the night’s brightest object hardly seems like a good idea!

Telescope and photography settings:

  • 254mm Dobsonian (homemade)
  • 1/500 sec exposure
  • ISO 24
  • F-stop: f/1.8
  • Focal length: 4mm
  • Q70 32mm eyepiece (2.00″)
  • iPhone XS with NightCap app on eyepiece mount
  • Touchups in PaintShop Pro and AfterShot Pro


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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