ISG: A spectacular view of the Perseid Meteor shower tonight!
Plus a look at gem peridot crystals in a meteorite......Pallasite!
The sky is falling on the world tonight! OK, not really the sky, but little bits of it far smaller than this iron-nickel meteorite shown at left. This 1.5 kilo chunk of a star fell in 1947 over the skies of eastern Siberia, and now resides in the ISG Student Reference Collection of StudyGems and Minerals. That event showered over 23 tons of meteorite material over the area providing some of the finest specimens of star stuff found anywhere on earth.
Tonight is a bit less risky for all of you star gazers out there as the earth will pass through the path of comet Swift-Tuttle that left a tail stream of tiny pebbles, ice and dust that will rain down on earth as the annual Perseid Meteor Shower.
Best viewing time is in the early morning hours between 0300 and 0600 hrs depending on your sunrise time. It is at this time that the rotation of the earth brings you into a position of riding the front of the earth as it travels through the comet's tail of debris. Since you are on the leading edge of the earth going through this debris trail the opportunity to see a lot of meteors it heightened. Its sort of like riding on the hood of a car going at high speed. The chance of getting really good views of bugs is far better than riding on the back bumper.
Due to the size of the cometary debris the vast majority of these meteors will burn up in the atmosphere as quick bright flashes of light. Very few will actually reach earth. At least very few that are big enough to see with your unaided eye. But more on that in a minute. Below are some specimens from the ISG Student Reference Collection of meteors from the Campo Del Cielo shower in Campo, Argentina. The piece below left is about 1.5cm while the smaller specimens are approximately .5cm each.
Gemstones from the Sky
A rare type of meteorite brings heavenly peridot to earth in the form of pallasites. These are iron rich meteorites that are thought to be either the remnants of long ago exploded planets, or perhaps smashed asteroids that were large enough to allow the iron elements to crystallize into the peridot crystals found inside them. These pallasites are often cut into slices to allow easier viewing of the peridot crystals inside. The polished iron metal creates a mirror effect that surrounds the peridot crystals as seen at left.
Truly an out-of-this-world opportunity to see gemstones from space!
We put our specimen seen above on a polariscope to see if these crystals were orientated in different directions in this specimen. As seen below, the crystals are orientated in different directions based on the variable reactions to the plane polarized light of the polariscope. In the image collection below: Top left is our pallasite in normal ambient light. Top right is in open polariscope position. Bottom left is in one turn of the polarizer with bottom right turned at 45 degrees. You can see how the peridot crystals in this pallasite grew in different orientations to each other.
Even more fun is to see the inclusions in these celestial gemstones. While we did not anticipate finding any lily pad inclusions as we saw in this newsletter last week, we did find some very interesting inclusions that in spite of their celestial origin showed some down to earth properties.
The top two images, left and center, show included needles along with a large included iron crystal. We found several of these with one breaking the surface that could be confirmed by Enwave Raman Microscope. Bottom two left and center show strange looking gas bubbles. Some of these were sliced through in the cutting process, emitting what we must assume were some out of this world gases to the cutter. And far right upper and lower you see gas bubbles illuminated by two different lighting directions. An interesting collection of inclusions from a peridot that is literally not from this earth!
Catch a Falling Star, put it in your pocket, never let it fade away.......
Just like the song says from the late and great Perry Como, you can actually catch a falling star and put it in your pocket right there at home.
Many falling stars make it to earth as micrometeorites. Microscopic versions of the big ones you saw above. These are also often made of iron-nickel and are therefore highly magnetic. To learn how to catch your own falling star all you have to do is look at the image at left of my back yard.
The roof of a house is a great catch place for micrometeorites that fall to earth by the ton on a daily basis. When it rains they are washed off the roof and, if you have a gutter system, they travel down your gutter down-pipe and onto your yard. During a meteor shower there is a higher number of these micrometeorites falling on your house than ever. Chances are pretty good that if you wash down the roof of your house and let the water run down your gutter, you can use one of the industrial grade magnets available anywhere these days to pick these micrometeorites off the ground around your gutter down pipe. Then view them through a microscope.
A few years ago the ISG provided Meiji Techno Microscopes for a NASA project to help school kids do the above for a NASA project. It works! While you are not guaranteed to find something every time, these micrometeorites fall continually on your house and yard. During a meteor shower the numbers go up dramatically. The odds of you being able to find some are much better over the coming days than at any other time. Just need a good magnet, a microscope to see them, and a little luck in finding them.
Need some luck? We can help with that too! Go out in late evening and find your first star that you can see.
Make a wish! Star light, star bright, the first star I see tonight........you know how it goes.
But be sure and get up in the early morning hours when you can sit on the front hood of the earth and ride it head on through space and watch the meteors coming at you. Just like bugs on a windshield!
You may lose a little sleep, but you will be witness to one of the greatest shows on earth!
The Sky is Falling......and you don't want to miss it!
Robert James
President, International School of Gemology
