Late

This is what 3am looks like in the control room.

This is what 3am looks like in the control room.

Visiting the Mayall 4 meter

The Steward Observatory’s Bok 2.3m telescope sits right beside the largest telescope on Kitt Peak Mountain: the Mayall 4 meter. I’ve posted pics of it many times, like here, and here, and here. I’ve walked up to it a few times and gone inside the visitor centre there, but an up-close look at the telescope is usually only afforded to those that are using the telescope. Happily, we met the operator of the telescope and he offered us a chance to see it. This is what it looks like when astronomers geek out over astronomy-type things:

The Mayall 4m was placed at the highest point of Kitt Peak, and is itself many stories high, making it the highest point on the mountain.

The Mayall 4m was placed at the highest point of Kitt Peak, and is itself many stories high, making it the highest point on the mountain.

Standing next to the telescope operator, I got to ask lots of questions.

Standing next to the telescope operator, I got to ask lots of questions.

Looking down the barrel of the 4m, it was turned on its side to fill up the instrument with liquid nitrogen (just like at the Bok). You'll notice in the mirror Pat is taking my picture...as I take his...

Looking down the barrel of the 4m, it was turned on its side to fill up the instrument dewar with liquid nitrogen (just like at the Bok). You’ll notice in the mirror Pat is taking my picture…as I take his…

From far away, the 4m looks a bit like the Millennium Falcon. Punch it Chewy.

From far away, the 4m looks a bit like the Millennium Falcon. Punch it Chewy.

Pat standing in front of the 4m on its side.

Pat standing in front of the 4m on its side.

Me at the prime focus of the 4m. helluva big scope.

Me at the prime focus of the 4m. helluva big scope.

8 meters

A telescope is defined by its collecting area. For an optical reflecting telescope, this is the diameter of its primary mirror. So how big can these mirrors get? Well, the York Observatory houses a telescope with a primary of 60 centimeters in diameter. I posted a picture of that mirror here when it was taken out for re-aluminizing. But mirrors can get a lot bigger than that. One of the largest mirrors in the world can be found at the Gemini Observatories (one in Hawaii atop Mauna Kea, and the other in Chile), which house telescopes with 8 meter primary mirrors. When the Gemini ‘scopes were being built, the National Optical Astronomy Observatory (NOAO) painted a circle on one of its outer walls the exact diameter of the primary mirrors of the new telescopes. Here’s me standing in front of that circle.

A circle 8 meters in diameter. I'm standing next to it for scale.

A circle 8 meters in diameter. I’m standing next to it for scale.

The largest optical reflecting telescope on the planet is the Gran Telescopio Canaris, in the Canary Islands. Here’s a list of the runner ups.

Sense of Scale

This provides a much needed sense of scale when looking at the Bok 2.3m telescope. That's 2.3 meters, or 230 centimeters...which means the primary mirror on the Bok telescope is larger in diameter than I am tall. We have the telescope tipped over to (almost) it's limit in order to flll the camera up with liquid nitrogen. Also in the image are the mirror cover (next to me) and the instrument we used (called 90prime) in the middle of the black ring

This provides a much needed sense of scale when looking at the Bok 2.3m telescope. That’s 2.3 meters, or 230 centimeters…which means the primary mirror on the Bok telescope is larger in diameter than I am tall. I could lay down comfortably on the mirror and fit easily (…but I won’t do that…). We have the telescope tipped over to (almost) its limit in order to flll the camera up with liquid nitrogen (the camera is that big black thing inside the black ring). Also in the picture is the mirror cover, the pyramid-like structure right next to me.

The Bok 2.3m in Action

Having fun with a GoPro Hero3 camera. Before any night time observing occurs, the telescope and instrument require set up, and calibration images need to be taken. We arrive about an hour before sunset (which was roughly 6:15pm local time during the week I was there) to start setup. First we fill the instrument’s dewar with liquid nitrogen to keep the instrument cold. Then we do calibration images. This time-lapse shows the hour of set up and calibration we did on one of our observing nights.

I couldn’t capture a time-lapse of the whole evening because the GoPro doesn’t work well at night. GoPro’s are designed for day time use. Ah wells.