Another day at the office

The MKWC weather forecast wasn't good, the evening should be fine but come the second half of the night the inversion layer was expected to break down and we stood a good chance of fog at the summit. This meant we had to get going early because I had a few engineering tasks I really wanted to get done which required decent conditions and a dome that was in equilibrium with the outside air temperature. Having a warm dome compared to the atmosphere means you get local turbulence which has quite an impact on image quality, and that would hurt our planned tests.

Still, there was time to wander outside and take the odd snapshot but it was hurried. The shadow of Mauna Kea was visible as usual (above) although at this time of year its relative position has moved so far from the actual summit that the pictures aren't so interesting from this location. The Earth's shadow was also just visible but still low on the horizon. By the time I'd taken that quick panorama I had to go back inside to get some of the calibrations started, but just before walking through the door I heard a commotion from some distance behind me.

Turning around I saw a sight I don't see often - the smaller than usual group of sightseers were making an awful lot of fuss and switching from one side of the summit road where they had watched the sun set into the Pacific and were now all quite excited and pointing over to the east. Flashlights were going off continually and one or two observatory vehicles, heading up to work for the night, were stuck behind the excited crowd.

I'm not absolutely certain what they saw, I couldn't see from my location, but I think someone probably saw the moon rise just above the clouds in the east and had said so. The message must have been passed along quickly because it was utter chaos for a couple of minutes! Unfortunately, I had to get back inside for a few minutes so couldn't go down to see what all the excitement was about, but I'm sure it was the moonrise.

About ten minutes later I was able to pop outside again, this time with tripod in hand. The weather system the MKWC had mentioned was clearly visible off to the west-north-west, seen as the reddish clouds in the distance behind the Subaru Observatory. These were supposed to move in overnight or at least the associated weather system was going to destabilize our atmosphere. It never happened and we left the summit at 6am very tired, cold and hungry but pleased after a really good night's work!

As ever, please click on the pictures if you want to see larger versions.