Some of them are smaller.

There must have been another cylinder down here. They cleared everyone out.

A cylinder reported by Huntington Beach. That's a job for the Navy.

In spite of the concentration of its resources on the study of cosmic dust (micrometeorites), the Department was able to investigate a large spectrum of meteoritic or planetary subjects.

From a meteorite from space, we re over here with an original Sputnik.

(c) Meteoroid registration of the fluxes of micro meteorites and technogenic particles along the ISS flight route

In the area of debris monitoring, Canada led an international team in 1997 to measure the Leonid meteorite flux.

The result of this work showed that Antarctic micrometeorites are a separate class of extraterrestrial material, with properties that are different from those of known meteorite classes and interplanetary dust particles.

So, this is called Victoria Crater, which is about a few football fields in size.

Rocks

It demonstrates mixing of lithologies from very different regions of the solar nebula.

Rocks

Crater, impact crater

It's that meteor.

Let that man alone! Let him alone!

The main mass of infalling matter on Earth is related to rare meteorite classes (CM and CR carbonaceous chondrites) but has mineralogical and bulk chemical features of its own.

The purpose was to make a crater to excavate the material and see what was underneath the surface of this comet, which we learned quite a bit about.

This is one very large crater. Geologists love craters, because craters are like digging a big hole in the ground without really working at it, and you can see what's below the surface.

In Meteor Crater it was made of metal, and metal is much tougher, so it made it to the ground.

Here is how big of a crater was left.

It's no meteor. That's for sure.

And then, of course, NASA also had a big announcement, and President Clinton gave a press conference, about this amazing discovery of life in a Martian meteorite.

The very unusual Kaidun chondrite is a chondrite breccia consisting of a variety of highly oxidized and highly reduced lithologies.

This is a rock that was about 30 yards across, so roughly the size of the ones that blew up over Tunguska and hit Arizona 50,000 years ago.

The formation of craters and associated effects of asteroid and comet impacts on the Earth are currently being analysed in a theoretical study involving advanced computer modelling and simulations.

To achieve a Mermaid's Downfall...

What about these meteor machines?

As I told you, geologists love craters.

The question as to whether there is life on Mars that is related to life on Earth has now been very muddied, because we now know, from Mars meteorites that have made it to Earth, that there's material that can be exchanged between those two planets.

There is a median point between tiny rock and gigantic rock, and in fact, if any of you have ever been to near Winslow, Arizona, there is a crater in the desert there that is so iconic that it is actually called Meteor Crater.

They've located that second meteor.

The satellite carried six experiments with different scientific objectives, including heat conductivity under microgravity, micrometeorite and dust particle distribution, atmospheric atomic oxygen mapping and re entry pressures and temperatures.

Meteorites delivered chemistry, and perhaps membranes, too.

Here is one that came in over the United States in October of 1992.

Do you know what a Mermaid's Downfall is?

The needle isn't pointing north. It's pointing toward the meteor.

And again, this was a rock probably roughly the size of this auditorium that we're sitting in.

And that's because the water protected the basin from being impacted by asteroids and meteorites.

Thus, the interplanetary dust is not represented by any of the meteorites in our collections and in all likelihood micrometeorites represent the silicate portion of comets.There is still no consensus on the origin of these crystalline melt droplets after which the most common meteorites, the chondrites, are named.

Now, this is not a 200 mile wide crater, but then again you can see the rock which is sitting right here, about the size of a football, that hit that car and did that damage.

That meteor is either very light, which is unheard of, or it's hollow.

This is an example of a real meteorite, and you can see all the melting of the iron from the speed and the heat when a meteorite hits the earth, and just how much of it survives and melts.

It turns out that these things don't have to hit the ground to do a lot of damage.

Now, when these things blow up, they're not going to do global ecological damage.

But it won't wipe out, you know, all life on Earth, so that's fine. But it turns out, you don't need something six miles across to do a lot of damage.