Mercury 2026-06-14 03:12 UTC. Eureka, surface detail.

I've been trying to capture surface detail on mercury for years.

finally succeeded. It's subtle, but you can see more than just a white/gray disk. the white blotches are likely bright spots around surface craters:

Mercury 2026-06-14 03:12.8 UTC
The bright spot that lies just below the mid-point of the second limb ringing is the crater Fonteyn and it's bright ejecta
IR-850

Here are 3 consecutive 9 minute captures showing consistent structure arguing against noise.  

Mercury 2026-06-14 03:12.8 UTC
3 separate 9 minute captures
IR-850

Here's a second version processed differently:

Mercury
6/14/2026 03:03.6 UTC
IR-850

image details:
East Bluff, CA

6/14/26 03:03-03:22 UTC 
camera ZWO ASI 290MM 
filters: ZWO IR-850
celestron 11" Edge HD, no barlow
firecapture
autstakkert (best 3%)
biggsky
photoshop upsampled 2x

the top image is the average of 3 with the outer section blended with the unsharpened version to cut down on the dark ringing artifact.

the bottom image is a single 9 minute capture upsampled 2x during stacking in autostakkert

sharpened in registax then photoshop, blended with unsharpened to cut down on dark ringing artifact.  

Thanks to Mercury Maven John Boudreau for confirmation and crater identification.  

the key seems to be a deep IR filter which minimizes the distortion from poor seeing at low altitude and maybe imaging in June with mercury's orbit more perpendicular to the horizon than other times.  biggsky's sharpening algorithm also helped.  

will have to try again some other time with more disk illuminated.  

3 separate captures:

Mid(UT)=030337.900

Duration=541.287s

FPS (avg.)=417

Shutter=2.347ms

Gain=351 (58%)

Histogramm=73%

20:03 local

alt 19 deg

Mid=201249.229

Duration=540.001s

FPS (avg.)=419

Shutter=2.347ms

Gain=351 (58%)

Histogramm=69%

20:12 local

alt 18 deg

Mid=202200.484

Duration=540.006s

FPS (avg.)=394

Shutter=2.347ms

Gain=351 (58%)

Histogramm=58%

20:22 local

alt 16 deg

Venus conjunction with jupiter and a new Thorlabs filter for venus

hope you've all enjoyed the conjunction of jupiter and venus after sunset.  here's a cellphone shot from my front yard:  

venus above jupiter
6/9/2026 8:48 pm

i've been taking the opportunity to point the bigger scope at venus with some success, catching cloud structure in ultraviolet light:  

Venus UV-IR
6/13/26
used the Baader UV for this

Venus UV
6/13/2026 03:33 UTC
cloud structure visible

Venus IR
6/13/26 04:07 UTC
partially illuminated disk without cloud  structure

Thorlabs ultraviolet filter:

i was informed that the Thorlabs UV filter (bandwidth 380-420 nm) is better than typical filters such as the baader U-filter for my system as the coatings on SCT scopes block much of the UV light in the range of the  U-filter.  i've been trying to capture images with this filter for the past year with no success.  i've dispensed with the barlow, tried earlier and later in the day...nothing but a white disk.  Having tried 2 days in a row with no contrast, i decided to run a comparison between the two...and voila i detect cloud structure with both filters!

i guess the take home is that you need to keep firing away for good atmospheric conditions on both earth and venus.  

Comparison below:

Baader U filter
320-380 nm
average of 2 nine minute captures
details below

Thorlabs UV filter 
380-420 nm
average of 2 nine minute captures
details below

My impression is that the contrast is better with the Baader filter, but the image is more blurry.  The Baader filter required 10 times the exposure as the Thorlabs (10 ms vs 1 ms) likely making the latter more effective at "freezing" seeing, giving a sharper image.  Now it's time to get out the Barlow where the transmission difference will be a more significant factor.  

Note, the Thorlabs filter came in an unconventional size, requiring a separate order of an adapter, so be sure and speak with someone about the appropriate adapter if ordering.  

image details:

East Bluff, CA

wide field Samsung galaxy S22 ultra

6/9/2026 8:48 pm

venus

6/13/26 03:15-04:07 UTC

camera ZWO ASI 290MM 

filters: Baader IR pass "685", Baader U-filter bw 320-380 nm, Thorlabs UV filter 380-420 nm

celestron 11" Edge HD, no barlow

firecapture

autstakkert (best 10%)

biggsky

photoshop

UV 350 nm 

03:33.5 UTC

20:33.5 local

alt 24 deg

Duration=540.004s

FPS (avg.)=91

Shutter=10.80ms

Gain=351 (58%)

Histogramm=71%

UV 350 nm 

03:43 UTC

20:43 local

alt 22 deg

Duration=540.000s

FPS (avg.)=67

Shutter=14.80ms

Gain=351 (58%)

Histogramm=91%

UV 400 nm

03:15 UTC

20:15 local

alt 28 deg

Duration=540.004s

FPS (avg.)=451

Shutter=1.022ms

Gain=351 (58%)

Histogramm=78%

UV 400 nm

03:58.3 UTC

20:58.3 local

Alt 18 deg

Duration=539.989s

FPS (avg.)=451

Shutter=1.818ms

Gain=351 (58%)

Histogramm=85%

IR 685 nm

(IR image above)

04:07.4 UTC

20:07.4 local

alt 17 deg

Duration=180.005s

FPS (avg.)=451

Shutter=0.119ms

Gain=306 (51%)