Thursday, December 29, 2016

Venus' clouds in motion!

I love astronomy that's no secret and one of the reasons why is that there is constantly something new to discover or a first to be had.  On December 28th, 2016 I had two firsts.  I was out to shoot Venus one last time for my yearly mash up (2016 pending!) and was in for a surprise or two.  First surprise is seeing a daytime Venus with the unaided eye.  I had a hard time getting my scope, +Akule  centered on my target.  So I whipped out my binoculars only to find it quite easily.  Realizing it was just above the trees I got excited as it should be easy to find.  Sure enough there it was, no telescope no binoculars but it was MID AFTERNOON in broad daylight!  I was astounded how clear the atmosphere was, 5/5 for transparency!  Second first for came after getting the the telescope and camera setup I was able to get a nice animation of the cloud tops.  I found the seeing above average and I had a long period of time to shoot before Venus slipped into the trees.  I shot from 20:49:24 UTC to 21:44:31 and was able to use the best seeing conditions to make this animation from time 4:19 to 4:38 EST or 19 minutes.  This animation of UltraViolet light shows how fast the cloud tops of Venus move in NINETEEN minutes!







So how fast do the clouds move? According to my good friends at Universe today, the winds "At the very top of the cloud layers on Venus, wind speeds reach 355 km/hour (or 100 meters/second). This is the same the jet stream here on Earth." 

But Mike are you sure it's not rotating? Yes, Very!! Why? Because the rotation period, aka a day on Venus is 116d 18h 0m. So you are certainly seeing the cloud tops blowing across the top of the atmosphere.

I also shot Venus in Infra Red and when you use Infra Red as Red, and UltraViolet as Blue, you can make a 50/50% mixture of those to make a fake green. Then using IR as R, UV as B and a synthetic Green you can make a false color or IR-sG-UV image of Venus. It looks like this...
After 

The UV is actually a derotated version of 8 x 90s or 12minutes of 'sub' time.  Here's the UV and IR alone.  Since it was daytime and the background levels were not dark, I left it bright enough to show the daytime UV levels.


Thank so much to my friends and family for sharing these firsts with me it was quite a fine way to end my 2016 observing season.  Stay tuned for the 2016 best of's!!

Mike

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