Ross Cunniff

Mars was at opposition (directly opposite the Sun from the Earth) on May 22, and Saturn was at opposition on June 2.  I've been itching to get some photos of them, and the combination of clear skies, reasonably good seeing (low upper-atmosphere turbulence) and time available made last night a good choice.  Without further ado, the photos: Although the photos say "June 5" I took them the night of June 4, local time, at about 10:12 PM and about 11:22 PM Mountain Daylight Time, from our back yard in Fort Collins, Colorado. My equipment was a Meade LX90 ACF 8" f/10 Schmidt-Cassegrain telescope mounted on an iOptron CEM-60.  The camera was a ZWO ASI174MM monochrome camera, with an RGB filter wheel and a 2.4x Barlow, which made the combo a 4800mm focal length f/24 system. Mars was taken with a 1.9ms shutter and a gain of 280 in FireCapture.  It was a 640x480 ROI, running at 182 FPS.  Saturn was taken with a 6.89ms shutter and a gain of 351, also a 640x480 RO...

Today (well, technically, yesterday now) was the 2016 Transit of Mercury.  These happen much more frequently than transits of Venus.  Mercury transits happen about every 7 years (13 or 14 times per century).  I was watching  the weather anxiously - I wanted this to be a dry run for the 2017 eclipse, but I was not able to travel on Monday so I was hoping that the weather would suffice here in Fort Collins.  I watched the Fort Collins cleardarksky page continuously over the weekend, which helped me stay calm and collect my equipment to prepare for the expedition. Monday morning started with low clouds which cleared by about 6:30 or so - just in time for me to have all my equipment set up: From left-to-right, these are: A Meade 2045 4-inch Schmidt-Cassegrain telescope on a tripod, with a glass front-surface solar filter.  This was for visual use - which turned out handy, since I had about 8 or 10 visitors. A Lunt Solar LS60PT pressure-tuned H-alpha...

I got up really early again this morning to catch the Moon, Venus, and Mercury dancing in the pre-dawn sky.  Here are a couple of my best shots.  The first one was taken from Larimer County Road 38E, where it curves into the foothills .  It was taken at 5:55 AM with a Canon 7DmkII and an EF 100-400 f/4.5-5.6L II lens, at 100mm f/4.5.  It is a 1.6 second exposure at ISO 800: For the curious, here is a map of the foreground showing what is visible in the 12.8 degree field-of-view of the lens: I drove home, and snapped one more picture above the neighbors' rooftops.  Same camera/lens/exposure settings: OK, *now* I can stop waking up early in the morning.

I got up this morning very early to make an animation of Jupiter, Mars, Saturn, the Moon, Venus, and Mercury as they rose in the early morning sky.  Here is the finished product: It was very cold - 7 degrees Fahrenheight - and very early.  This is a 30-minute sequence starting at 5:39 AM and finishing at 6:09 AM.  All of the images have the same parameters: Canon 7DmkII camera Canon 8-15mm f/4L lens, locked at 10mm (widest useful zoom with this lens on a 1.6x crop camera) 8 second exposures at ISO 3200 Image sequencing performed by Canon's EOS Utility.  A capture was started every 15 seconds. That camera/lens combo yields a 180-degree diagonal field-of-view.  Jupiter and Mercury are about 120 degrees apart in these images, so this gives some extra room for animation and cropping. Capturing all five planets in the pre-dawn skyglow is surprisingly tricky, especially when city light pollution is contributing to a murky lower atmosphere. ...