A Blue Jet

Having an array of cameras on the summit of Mauna kea that capture images all night long has advantages. While the cameras are intended to allow the telescope operators to monitor the weather, they do catch other atmospheric phenomena.

In this case is it a powerful blue jet, a form of upper atmospheric lightning. While these sort of events had been reported for decades, mostly by aircraft pilots, they were only acknowledged by meteorologists after they were first photographed in 1989.

My friend Steve Cullen first noticed the jet in an image from one of the Gemini North CloudCams. It jets upwards from a strong thunderstorm cell passing north of the island, part of the remains of Hurricane Fernanda.

Unfortunately our Keck CloudCam is pointed just a little too west to have captured this event. The next night our camera captures several red sprites, but they are rather distant.

The various cameras capture sprites and jets with a fair regularity anytime there are strong thunderstorms around the islands. If a hurricane is anywhere in the vicinity it pays to check the archives. This jet is bar far the most impressive yet.

Enjoy the image…

A blue jet as seen from Mauna Kea on the night of 23July, 2017
A blue jet from a thunderstorm passing north of the island. Original image is a CloudCam image courtesy Gemini Observatory/AURA

Update: On Facebook we were having a discussion about how tall the jet was. I calculated the image scale of the camera, a Canon XTi with a 20mm lens, arriving at about 59 arcseconds per pixel. I also measured the jet as 840 pixels high (there is some extension of the upper part in a hard stretch of the image). Thus the jet is 13.74 degrees high, now all you need is distance to the cell.

Tom Polakis found a good satellite image from the night in question showing the storm about 210 miles away from the summit of Mauna Kea. This and a little trigonometry shows the jet rose about 51 miles above the top of the storm clouds!


Some parts of the job are simply fun. Installing the various upgrades to the weather system has been just that. The latest piece of kit being more fun than usual.

Weather Mast
The Keck weather mast with a sonic anemometer at top, MastCam, and the housings for the temperature, humidity and barometric pressure sensors.
We are installing a number of new cameras throughout the facility. Replacing an ancient CCTV system that still uses composite video and black and white monitors. Yeah, that ancient. The system is quite useful, it allows visibility of the telescopes from the operator stations and the manual control panels when you are driving the telescope.

Even that is topped by the camera I installed this fall. The latest camera is a new pan-tilt-zoom camera attached to the weather mast.

The camera does have more prosaic reasons to justify the effort of installing it. With the camera the operators can observe the weather conditions around the telescope, observing supervisors can view the ice and snow on the domes from Waimea, the day crew can check the weather conditions before driving to the summit, and more. The camera does have enough sensitivity to see the brighter stars and the banks of fog that roll over the summit. In full dark and at full gain the image is noisy and faint, not all that great. Given just a little moonlight the performance is much better, allowing visibility of oncoming clouds.

MastCam Ice
Hanging ice blocks the view of MastCam after a severe winter storm on January 4th, 2015
Weather conditions can be extreme on the summit. Last week’s storm being a good example… 100mph sustained winds, 135mph gusts, more than a foot of ice coating any vertical surface and several inches on the ground. The camera is rated to survive such conditions, and has now survived its first major winter storm. Electronic operation is guaranteed by the manufacturer for -40°C, and there is a heater and blower inside the camera dome to remove ice. It was able to melt its way clear, at least partially on the first day, while it took a week to clear the domes for operation.

Even more fun! On Christmas Eve I was contacted by Hawaii News Now for photos of the storm, they were eager to do something about a white Christmas for the evening news. As I had not been to the summit and no one on our crew was up, I simply grabbed some MastCam images and forwarded them. The images were aired in the first couple minutes of the Honolulu evening news!

The camera is not available to the public, it would be too much wear and tear to the pan-tilt mechanism and a huge hog of bandwidth. You have to be inside the Keck network to use, from there it is available to anyone on staff. It has proven quite popular, with many folks using the imagery to check on mountain conditions in the latest bad weather.

Next up, yet more cameras in the dome and even a couple on top of the domes. there is also a precipitation sensor and more in the works for the weather station.

OK, enough fun, back to revising the Keck 2 dome schematics.

Thunderstorms Captured by the Keck CloudCam

Our new CloudCam is undergoing testing. It assembles a video each night, just like the original CFHT CloudCam. The website is not quite public yet, but I had to share this one…

Heather mentioned at breakfast that she had been watching thunderstorms on CloudCam as she ran the telescope through the night. Thanks to the new camera we can all enjoy the spectacle.

Working Late Again

When most folks work late at the office it is a boring evening at a desk staring at a computer. I may have stared at a computer a bit, but it was hardly a boring evening.

CloudCam Image
A focusing test shot from the Keck CloudCam
The task that had me staying late was to focus the new cloud camera. To accomplish this task I needed a dark sky and stars. The plan is the same as I have used before, work the day and then stay into the evening.

Waiting for darkness had it’s advantages, an opportunity to do a little photography. In addition to the usual tool bag and lunch I took my camera gear with me.

With Sniffen on the roof while I watched the frames on the computer, I called the corrections up to him on the radio. It is tricky work to focus a fast lens, made worse by the need to do it remotely. We had to wait for each 30 second exposure, painfully slow. I hesitated to ask Sniffen to sit much longer out in the cold, but he was game and ready to assist. His tiny adjustments were deftly made, I watched as the lens moved through focus.

VLBA & Milky Way
The summer Milky Way soars over the VLBA antenna atop Mauna Kea
The focus is not as good as I would like to see, I suspect that the Sigma 18mm f/1.8 lens leaves a little to be desired when used wide open. Perhaps one of the Rokinon lenses would work better. Or maybe I just need to step the lens down a stop or two.

After leaving Keck I took my time wandering down the mountain. I stopped at IRTF for a set of panorama shots. One of the first things I noted was the lack of airglow. Last time I shot from the summit the airglow was intense. Despite using the same camera and lens, with the same settings, the bright red glow was missing. Only a pale green near the horizon to be seen in the shots.

On a whim, I drove out to the VLBA antenna for a set of shots. This radio telescope was something different than the usual telescope shots I take. I walked around the dish until I could position the summer Milky Way beside the antenna. As the VLBA is a radio telescope there was no issue in using a little light from my flashlight to paint the dish and illuminate it for the photo.

I arrived home just before midnight, tired from a full day on the summit. The photos will wait for another day for processing.

The Keck CloudCam

It works! We now have a CloudCam at Keck. It is not quite ready for full active service, but it is alive and taking images. I got the network connection running yesterday, after mounting the camera and running the various cables over the last couple weeks. A little time for commissioning and getting the software setup and the camera will be available to everyone.

Keck CloudCam
The housing for the Keck CloudCam ready for the worst in Mauna Kea weather.

Our camera was built by Kanoa over at the Canada France Hawaii Telescope. Kanoa built the first CloudCam that has served CFHT so well. In service for a couple years now, the CFHT CloudCam gives our telescope operators an unparalleled view of the weather. This is critically important as heavy fog, rain or snow can damage the telescope optical coatings.

Post Update… The Keck CloudCam Link!
Video Archive

To secure and protect the enclosure Kanoa built I fabricated a solid mount. A heavy machined plate and an aluminum cover should shield the camera from the worst that Mauna Kea Weather can dish out. The camera electronics warm the box nicely and a heater is installed to warm and deice the window. We shall see how it fares, the summit weather can be amazing.

With the original CloudCam pointing east, over Hilo, our CloudCam points west, a complementary view of the weather approaching the summit from either direction. The imagery will be closely monitored by all of the telescope operators on the summit during marginal weather.

The imagery will be available to the public as well. Expect live images as well as compiled movies of each night. The first CloudCam has quite a following, quite a few people check the camera constantly. This includes quite a few UFO consipracists. If anything odd shows up on the camera the video quickly shows up on YouTube and linked to postings on the UFO sites.

Yes, the focus needs to be adjusted (I expected that), but the scene covers a nice range from the Waikoloa resorts on the left, past Kawaihae, to Waimea on the right.

CloudCam at Keck
A test image from the Keck CloudCam

And after focus adjustment we get much nicer stars…

CloudCam Image
A CloudCam image showing the lights of Waikoloa, Waimea, and a lot of evening inter-island air traffic.

Watching for ISON with Cloudcam

Wondering what comet C/2012 S1 ISON is looking like today? There is a very good camera aimed at the eastern horizon from the summit of Mauna Kea. Just what you need to take a look for yourself.

The CFHT Cloudcam is a DSLR camera that is programmed to take exposures constantly through the night. Used by the telescope operators to monitor oncoming weather, the camera shows the sky conditions over the eastern coast of the island and the city of Hilo. The images are live during the night, each morning you can load a timelapse video of the entire night.

The camera has quite a following, quite a few people check the camera constantly. This includes quite a few UFO consipracists. If anything odd shows up on the camera the video quickly shows up on YouTube and linked to postings on the UFO sites. When the launch of a missile from Vandenberg AFB in California created a glowing sphere of light these websites went into overdrive with wild speculation.

Most of the mornings this week have been too cloudy to see the comet. I have been checking the video each day. Currently at magnitude 5 the comet will be a small dot in the imagery. As the comet brightens it should appear nicely in Cloudcam.

Latest Cloudcam Image
The latest Cloudcam image