Tuesday, October 21, 2008

Welcome JTI Bus Tour To Kitt Peak!

I would like to welcome you all to Kitt Peak National Observatory! I know it has been a long bus trip from Racine. Let me show you around a little bit.

Our first stop will be the McMath-Pierce Solar Telescope. It is that weird looking thing that is described as a sideways 7. It is the world's largest solar telescope. The tunnel is 500 feet long...you only see 200 feet of that above ground, so most of that thing is below ground! Let's go inside.

Sorry about the glare. It's a little bright in here when they are observing. You can see the main mirror way down there at the bottom. A mirror at the top (called a heliostat) bounces light down the tube to the mirror. The mirror then focuses the light. A third small mirror bounces it down to the observing room. Speaking of the observing room...

There is Claude, an observer at the solar telescope. He has set up the telescope to project an image of the Sun onto a table. The image is about 80cm across. You can see sunspots on this or direct the Sun into different instruments, such as spectrographs, to record the data.

Let's go to another telescope. This is the WIYN 3.5 meter telescope. It was built in 1994 and is the newest large research telescope. It has a wide variety of imagers and a multi-fiber spectrograph that can take spectra of a lot of objects at the same time (I forget the exact number...we can ask them down in the control room). You can see a person standing next to it for scale.

Take a lootk at the back of the telescope. Each of those little guys you see there is an acuator. An acuator is a small motor that pushes and pulls on the mirror. Modern mirrors are very thin to make them lighter. Thin mirrors bend under the influence of gravity as the telescope moves. All these little motors push and pull on the mirror to keep it from becoming deformed and giving distorted images.

Our last stop will be the largest optical telescope on Kitt Peak, the Mayall 4 meter telescope. It was the second largest telescope in the world when it was built back in the 1970s. Thanks to continuous updates to its instruments, it still does premiere scientific research on such areas as dark matter. It recently got a new infrared camera called NEWFIRM which is producing lots of good new science.

I hope you have enjoyed your tour of Kitt Peak. Do stop by again...don't miss the Desert Museum or the Pima Air and Space Museum.

And Orbs, don't play with the snakes!

8 comments:

MinnesotaChick said...

woohoooooo!! I'm still on the bus!

Thanks for the tour Hale. Totally enjoyed it. *thumbs up*

Lizardmom said...

awesome tour Hale, thanks!!

kkdither said...

Thanks for the insider view. Now I want to visit for real! Nobody mentioned there would be snakes though! Eeeeeek!!!!!! p.s. Bonjour Claude!

Anonymous said...

Where's the gift shop?

OrbsCorbs said...

Apparently, it is cheaper/more efficient to add a mess of small motors rather than thickening the mirror?

Snakes? Yeah, I've noticed that when I've been in the southwest. Y'all got snakes and lizards and armadillos and stuff. That's Lizardmom territory.

Lizardmom said...

whoa, hold it a minute there Orbs, I am LIZARDmom, not SNAKEmom, eww, I only like things with legs, snakes don't qualify!

drewzepmeister said...

Fantastic tour,hale! Thanks! This is way better than the Modine Benstead. Now,I want to visit for sure.(Snakes don't bother me) Just how powerful are these telescopes?

hale-bopp said...

Glad you enjoyed the tour. The Modine Bensted Obervatory has some nice telescopes for the public...the big guys at Kitt Peak don't even have eyepieces to look through (except on very special occasions...I got to look through the 3.5 meter telescope briefly earlier this year).

It's had to say what is meant by "powerful". Astronomers don't use magnification as a measure of power as most people do. There are two important features: light gathering ability and resolution.

Larger telescopes gather more light. Doubling the diameter of a telescope means you gather 4 times as much light (remember the are of a circle is 4*pie*r^2). These telescopes gather millions of times the light of your eye.

The other important thing is resolution. Resolution is the ability of a telescope to see fine detail. If I am standing next to you and hold up two fingers, your eyes resolve my fingers: you can see there are two. If I start walking away from you, at some point, you can't see I am holding up two fingers. At that point, you can't resolve my fingers. The resolution of a telescope depends on its diameter and the wavelength of light you are observing. Doubling the diameter will let you resolve objects half as large. In reality, resolution is limited by Earth's turbulent atmosphere.

So they are good telescopes, but not the largest in the world. In astronomy research, the rule is that you use the smallest telescope to get the data you need and leave the big telescopes to the work only they can do.