Annular Eclipse, Grand Canyon

The track of yesterday’s annular eclipse crossed just north of here, and for the first time in my life I was in a place with guaranteed clear skies, so I went to the Grand Canyon to look at it.

Of course, so did a few other people…

Some with fancier equipment than others

The sun’s only 93,000,000 miles away. How big a lens do you need?

First contact. (BTW, my lens isn’t dirty – the smudges are sunspots)

Our ‘Scope of the Month’ Centerfold

But my little camera and a piece of welder’s glass did me proud

Not everyone needed a telescope

Without a filter it was pretty hopeless

So trying to get the scenery in just made it look like a normal day

But it was still partial at sunset, so finally I managed to get a shot of sun and canyon together


LLLeonids… Brr!

Like a fool I got up in the middle of last night and drove out to Lake Mary to watch the Leonids. I have to say, nature could have gone to a bit more effort – they weren’t at their best. Nevertheless I saw 37 meteors in two hours, although at least five of these weren’t Leonids because they came from a wildly different direction, were much slower and had longer tracks. The Leonids themselves were short, sharp and tended to have a blue-green ionization track, but I’ve seen far brighter and better meteors.

The stars however were stunning! I could have read a book by starlight on this wonderful moonless night. Nowhere in the US could have had better viewing conditions than Flagstaff. I could see quite a few nebulae and clusters with the naked eye, and the Orion nebula had a distinct mauve tint.

The Milky Way looking towards Flagstaff

Only three meteors were kind enough to step in front of my camera – this was the best of the three (the other two I didn’t even see with the naked eye):

All the good ones hid away from my lens!

In this animated GIF you should be able to see a bit of space junk I captured by accident. I don’t think it was a satellite because it was very dim and wasn’t on a polar orbit. Each frame is a 30-second exposure, so it certainly wasn’t a meteor. The big blob bottom-left is Mars and the cluster above it I’m pretty sure is M44.

Floating junk or a small and oddly orbiting satellite

It was all very beautiful, but the air was 17 degrees below freezing and so when I started to lose my third toe to frostbite I decided to call it a night. By then it was about 3.30am, mountain time, and I bet you anything the best meteors were just waiting in the wings for me to turn my back!

37 meteors was pretty nice, and not far from the forecast frequency, although it wasn’t quite as good as the 1,000 or more per minute seen in 1833, which must have been stunning. It reminded me very much of the night my son was born. I’d gone to the hospital with Ann in the ambulance – blue flashing lights across the lonely hills to Chesterfield, about 10 miles from where we lived. After Chris had been born it was too late at night to find a taxi (even if I could have afforded one), so I had little choice but to hike home across the Pennines. Once I got to the last streetlight it was like walking into a black wall. I couldn’t see anything at all and had to feel my way with my feet for the next half hour. But by the time I was on top of the fells, the stars were on full form and a meteor shower guided me home as if I was in a scene from the Bible! A memorable night.

An aircraft heads for the Milky Way

Celestial mechanics


Yesterday my new friends Holly and Dan took me (along with Dan’s family) to see the Discovery Channel Telescope, which is part of the Lowell Observatory. Or rather they took us to see the building the telescope will eventually be housed in, which is more interesting than you might think, given how huge and heavy the telescope is, and how vibrationally and thermally stable it has to be. Dan’s a software engineer, responsible for all the embedded systems that manage the huge shutter doors, rotating turret, etc., etc. I do embedded code myself, sometimes, and get nervous enough hitting RUN the first time a robot limb controller or whatever goes live. Imagine the tension the first time you let a little microcontroller loose on umpteen tons of precision steel!

The building reminds me of a Dutch windmill with no sails

The building reminds me of a Dutch windmill with no sails

The telescope is sited deep in the beautiful Coconino Forest, southeast of Flagstaff. The mirror is still awaiting polishing in Tucson, but eventually it will be stuffed into a padded envelope and mailed by UPS to the site, ready for silvering. Here’s a photo of the on-site vacuum chamber where it will be resilvered every two years. The bottom part will hold the mirror and slides out on tracks, from where it will be wheeled to the telescope. Rather them than me – I can’t be trusted with glass. “Down a bit. Left a bit… no hang on, I meant right, sorry… ooh…”

Holly and Dan in front of the vacuum chamber

Holly and Dan in front of the vacuum chamber

The mirror itself is 4.2 metres in diameter, and the telescope configuration has multiple focuses for both wide-field and high magnification use. According to my calculations it will gather more than 1700 times as much light as the little 4″ reflector I used to have! Dan says it’s optically perfect to within one wavelength across its diameter, and the silvering averages three atoms thick! Under and around the mirror are hundreds of pistons that keep it in shape (adjusted at 20Hz) as the glass tries to sag under its own weight when the telescope tilts and tracks.

Middle floor - where the telescope base will be

Middle floor - where the telescope base will be

The observatory building is on three levels and the base of the central mount is a massive concrete pillar and concrete cylinder, which have been aligned with the Earth’s radius by geostationary satellite. Everything’s carefully designed to minimise vibration and avoid temperature fluctuations across the metalwork.

Upper floor, facing the main shutters

Upper floor, facing the main shutters

The entire telescope and upper section rotates on these hefty rollers, with pressurised oil bearings.

Inch-thick steel track lying on one of the turret bearings

Inch-thick steel track lying on one of the turret bearings

It won’t be finished for at least another year, but it was fascinating to see it under construction. On the way back we went to Sedona and hit things just right for a perfect sunset. Then Dan and Holly kindly treated me to dinner. Climbing back up Oak Creek Canyon the stars were, of course, stunningly bright, Can’t wait to see them up close! Fascinating. Thanks guys!

Sedona 500