Johnson Family Tour of Palomar Observatory

Sunday morning we woke up early, packed a picnic lunch, loaded the kids into the car, and headed South for a day at Palomar Observatory, one of Caltech's optical observatories, along with Keck. I had arranged for our visit with the site manager Dan, who volunteered to give us a private tour of all four active telescopes on the mountain, including the 60-inch (five-foot diameter) also known as the P60, the Oschin 48-inch Schmidt (P48), the little 24-inch, and the mighty 200-inch Hale Telescope.

When we saw the P60 and P48, Owen was fairly impressed, as was Marcus. They both said, "whoooaaahh" when we saw the "medium-sized" telescopes and they definitely wanted to touch their shiny exteriors. Owen was nervous about some of the steep, narrow stairwells. Marcus wanted to touch the hard hats hanging on the walls.

After the first two telescopes we ate lunch at the "Monastery," which is the fancy name for the observer's dorm rooms. Back in the day women weren't allowed to observe, so it really was a lot like a monastery. After eating lunch and grabbing some "special treats" from the big bowl of observing candy, it was time to head off to see the pride of Palomar Mountain. We entered through the ground level where we saw the impressive, 1930s-engineered supporting structure for the dome and telescope, along with various oil pumps and cool looking equipment. We then went up the narrow stars and entered the dome through a side entrance, which led directly under the monstrous 200-inch telescope. Owen's eyes lit up, and so did ours. For the first time all day Owen was literally speechless.

Here he is right after we entered the dome floor

Hanging under the telescope is the Cassegrain instrument cage, which is big enough for a few people to work standing up. In the picture below you get a better sense of scale. The outline on the floor is roughly the size of the 5-meter primary mirror, which rests just above the instrument cage.

There was a scale model of the telescope set up to the side where Owen & Marcus were able to press buttons on an actual-size control paddle to move the model telescope North, South, East and West. We then went up another level to the visitor's deck, about 20 feet off of the dome floor. Dan then went down and started moving the telescope. Then he started moving the gigantic 1000-ton dome, which sits on a nearly frictionless set of well-oiled bearings. It was a weird sensation trying to figure out if we were moving, or if it was the telescope moving while we stayed still. Here's a movie:



While the dome and telescope were moving, Owen stood in rapt attention and then suddenly exclaimed, "Daddy. Nothing is better than this!!" I had to agree. It's certainly not every day that you get to watch a 1000-ton telescope slew while standing on a 1000-ton moving platform.
I really love my job!

After seeing the biggest telescope on the mountain, we hiked over to see the smallest one, the 24-inch telescope, or the TFT as my colleague Mike Brown likes to call it (two-foot telescope, as opposed to the TMT or Thirty-Meter Telescope, the new Caltech/UC telescope soon to be built in Hawaii).

Uncle Dan and Marcus on the way to the TFT

Owen and me outside the TFT

I did my thesis observing on a 24-inch telescope, the CAT, at Lick Observatory. So I have a special place in my heart for the littlest telescope on the mountain.

Another fun part of the day was when Owen "drove" the car from the P60 over to the Monastary. He sat on my lap and steered as I held the car at a steady 7 mph on the empty mountain-top road.

Here are some more pictures from our fun family outing:

Outside the coude room.


Here's a picture of the laser guide star in action, taken by someone with a much better camera than mine!

Eye protection is key, even when the laser is no longer operational.

Owen waits on a long exposure...

Mar drives, too!

Outside the Oschin 48-inch telescope.