My wife and I finally got up to Griffith Observatory for a visit last month. It has been open for several months since its major overhaul. There is an entirely new area beneath the old observatory and that is where the meteorites and related displays are. They did keep a lot of the old displays however. The solar astronomy portion of the observatory was mostly like it used to be. The Tesla Coil is still there and they run it if you ask. But it longer lights fluorescent bulbs and lamps of various gas combinations. They have it in an EMI screened setting with a grill of copper bars surrounding it. I wondered whether this was for safety of visitors or for safety of electronic equipment now so easily damaged by the radiations Tesla Coils produce. There has always been concern among many of us who run Tesla Coils about the high frequency-high voltage emissions and their long term detrimental effects. I did not ask the docent about the copper cage this visit maybe next trip. Of the old displays that were kept were the two large Canyon Diablos. One is pictured here mounted as it has always been. I noted this time the wording on the name plate. They came so close to using the scientific designation for the crater but missed the mark. I guess one can called it Meteor Crater the generally accepted public name but Barringer Meteorite Crater not Barringer Meteor Crater is of course the correct name in our circle of interest. They are very nice specimens still.
There is a beautiful piece of lunar material on display. It is a chunk of the so-called ďBig BerthaĒ stone, a 19.8 pound rock returned to Earth by Apollo 14. The nice size fragment is on loan from NASA. The picture below is a color image. There is just no color in the specimen and no color was used in the display itself.
There were displays for all the major categories of meteorites. They have some very nice stones and irons to see. A nice large Allende caught my eye and posed for a photo that I may use another time. A case was devoted to impact materials and tektites. The tektites were from the collection of Darryl Futrell our friend. It was nice to see that even though he is gone his legacy of sharing tektites with the world continues.
The display case for California meteorites was filled with names I recognized. Bob and Beth Verish and Rob Matson to mention a couple of them. I am wondering if some of the dots on the map are for Paul and Jimís finds. There are very few reference points like city names and a lot of open space in the California desert and many dots on the map. Guess I will ask Bob next time I see him. It does say that it is for all the California finds so I think ours are in the dot clusters somewhere.
The planetarium show was wonderful and the projector great. New seats make the experience much nicer than the wooden head rests of the old chairs.
They have got one small (no joke intended) problem. The outdoor solar system display in front of the historic building has name plaques for the planets made of brass or bronze and circles of metal for the orbits set in the concrete of the sidewalks. Most of the worlds fall within the area just at the foot of the entrance steps. But out about half way to the parking area is the circle and name plate for an object called Pluto. Which as we all heard in the last few days is not even the largest of the dwarf planets anymore. And it will of course no longer be listed among the officially recognized planets. I for one would vote to keep the sidewalk and its Pluto circle just as they are. It was a wonderful visual tool when first created decades ago and it is part of the rich history of the Griffith Observatory.
And now for something completely different
Iíve mentioned over the last few months that I had a big meteorite cutting backlog. Well I have been working hard at the saw and lap and have much of that work complete. Those slices and end pieces will soon be appearing at a catalog page near you. Paul has been working very hard on the websites and that has included our catalog and store. We have a good supply of meteorites which I am not cutting at this time. But, I am cutting up about thirty pounds of stone into slices and ends. Thatís a lot of pieces to lap and many to also polish.
We have several meteorites that we had classified with numbers unique to our catalog. I guess that is common for all dealers now. As it happens we have been really lucky to obtain some very nice material.
NWA 774 for instance is one I used a picture of last month. It is a chondrule rich stone that is very attractive when not highly polished. The chondrules are very easy to see on the lapped surface and it is one of the few meteorites that I have ever had where you can make out the radial pyroxene chondrules with the naked eye. I love smoothing up the slices of this meteorite and seeing all those little round beauties set in the slate gray matrix spider webbed with shock lines.
Another of our stones that I am slicing more of right now is NWA 775. This was a fun meteorite with a great story which I think we told in the past. Its an L chondrite with large masses of a very fine grained light colored material scattered through it. Making it one of the zenolithic Lís that have appeared the last few years. These masses are often oval and as large as a kidney bean. I was intrigued from the beginning with this meteorite as soon as I saw its reddish purple fusion crust. it has never been a disappointment since.
We have cut on these stones before and I am getting to the end of some of them now. Others we still have big chunks remaining for more cutting sessions in the future. I have made thin sections of most of these. We have thin sections for some that were extras made at the time they were classified. It is always fun to be able to look through the microscope and down into the tiny details of the stones that I am slicing and polishing. I get a big kick out of knowing that my slices will be enjoyed and learned from for years to come. I think about that often while getting wet and dirty cutting. There are always surprises. As I cut up a large NWA 869 yesterday I wondered what I would get to see. And I was not disappointed. I had several slices with large metal grains of strange shapes, and three slices with troilite inclusions attached to metal grains. Good fun. If there is a meteorite that always holds something new it is NWA 869.
Well, I guess it is time to get back to work. Or is it fun? Some days it is hard to tell the difference when its meteorite cutting time. Til next month enjoy.