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Welcome to the Closing Webcast for the Cratering the Moon Challenge
Wednesday, May 9, 2008
See more information on the Challenge

Transcript of webcast:

>> Hello welcome to the cratering the Moon Quest Challenge.

This is the final webcast in the first of the LCROSS Quest challenges.

Let's talk a little bit about or let's review just what LCROSS is.

We have a brief video for you.



Lunar CRater Observation and Sensing Satellite (LCROSS): A First Step in the Return to the Moon Video Transcript:

S. Pete Worden, Center Director, NASA Ames.
More than 35 years have passed since humans last walked on the Moon. NASA’s current mission is to once again take a giant leap for mankind by establishing a human outpost on the Moon. To pave the way, robotic missions surveying the Moon will launch in late 2008.

Dan Andrews: Project Manager, LCROSS
The Lunar Reconnaissance Orbiter or LRO and Lunar Crater Observation and Sensing Satellite or LCROSS will launch together on an Atlas-Five rocket.

Anthony Colaprete, Principal Investigator, LCROSS
Their mission is to provide critical information to NASA as it plans our future on the Moon.

Dan Andrews:
We here at NASA Ames Research Center are extremely excited to be designing and conducting the LCROSS mission. The goal is to determine if water, perhaps in the form of ice or hydrated minerals, exists inside a permanently shadowed crater on the South Pole of the Moon.

Mark Shirley, Software Lead, LCROSS
Water is an extremely valuable and versatile resource. Water can be split into hydrogen for rocket fuel and oxygen for breathing. It can be mixed with moondust to make concrete used in building shelters. It also makes an excellent shield to protect against radiation.

Since any ice on the Moon might be buried underneath a layer of rock and dust, we need some method of getting the ice out into the open and detecting it.

Jennifer Heldmann, Co-Investigator, LCROSS:
The LCROSS mission accomplishes this with two space vehicles. The Centaur upper stage of our Moon rocket will be used as a 2200-kilogram kinetic impactor, excavating a crater approximately 20 meters wide and almost 3 meters deep. More than 250 metric tons of lunar dust will be lofted above the surface of the Moon.

Dan Andrews:
The Shepherding Spacecraft, built by our partner Northrop Grumman, guides the Centaur upper stage to the target. It also carries cameras, spectrometers and a photometer to analyze the debris plume to look for the presence of water vapor, ice, hydrocarbons, and hydrogen, which is one of components of water.

Anthony Colaprete:
The science instruments onboard the LCROSS spacecraft cover an extremely wide spectrum. We have spectrometers that can see organics, hydrocarbons, and byproducts of water ice. We also have infrared cameras that can see hydrated minerals, water ice and water vapor. In addition to telling us if water exists on the Moon, the science that comes out of this data will be used for many years beyond the LCROSS mission.

Mark Shirley:
Two hours after launch, LRO will separate from LCROSS and continue on its way to the Moon. Five days after launch, LCROSS and the attached Centaur will execute a fly-by of the Moon. They will then enter into several large, looping orbits around the Earth for the next few months of the mission. We will use this time to check instrument calibration and refine our trajectory for lunar impact.

Dan Andrews:
About seven hours before impact, the Shepherding Spacecraft will separate from the Centaur and position itself to observe the impact at the south pole of the Moon. For the next four minutes after the impact of the Centaur, we will receive real-time data as the Shepherding Spacecraft flies through the plume and scans the ejecta for signs of water.

Anthonly Colaprete:
The Shepherding Spacecraft will then impact the Moon, creating a second plume of lunar dust.

Jennifer Heldmann:
Both impacts will be closely observed by professional astronomers on the Earth, using some of the world’s greatest observatories. We also believe there is a chance that the impact plume may be visible in 10 to 12 inch amateur telescopes. We are encouraging both professional and backyard astronomers to participate and contribute their observations to this exciting mission.

Dan Andrews:
We are at a key point in human history. Humanity is preparing for its next stage in our development and that stage is settling the solar system.

Tony Colarete:
As NASA moves forward with our exploration programs, one of the most important things we need to figure out is how people can live for long periods, and eventually permanently, off the Earth.

Mark Shirley:
If we can identify water ice at the poles of the Moon, we can use that water to live off the land.

Dan Andrews:
We are excited, proud and honored that the LCROSS mission has been chosen to be a first step on our long journey as humankind takes its next giant leap back to the Moon, to Mars and beyond.

-------------------------------------end of video--------------------------------


>> All right.

Now let's review how you've been participating in this mission.

As junior engineers your job this challenge has been to design and build an experimental test rig that would simulate the LCROSS impact on the Moon.

What this rig was to do was to send a projectile into simulated Moon soil and create a crater.

Your rig was also supposed to be designed to send this projectile in at different angles so that you can test what effect this angle of impact has on the size of the crater and the amount of material that you are excavating from the surface of the Moon.

Now, we know from our communications with the classrooms that a number of you are still building your rigs and doing the tests.

We encourage you to keep doing this work, send that in to us along with pictures so that we can post this and show what your designs are.

We also understand that this webcast is happening a little bit early.

A lot of you are in end of year testing coming up.

We hope you're having fun with that.

But we are going to be talking a lot about this procedure, this experimental simulation, and we're looking forward to hearing your results.

My name is Brian, I work on the LCROSS mission and I am helping to get the word out about the mission to students and the public.

Today we have two of our scientists involved in the mission.

We have Dr. Jennifer Heldmann and we have Dr. Peter Schultz.

Jennifer, could you talk a little bit about what it is that you are doing as a scientist on this mission?


>> Sure.

Thanks, Brian.

For the LCROSS mission we have a science team so there is a whole group of scientists that work together and Pete and I are both on that science team.

There are a lot of different activities science related we have to do to support the LCROSS mission.

Some of the types of things we work on are picking sites on where we're going to impact on the Moon.

So we take lunar data that has been collected from spacecraft and the Earth that was looked at the Moon and try to pick the best spot we think the LCROSS mission should impact.

There are a lot of different factors that go into where should we impact?

As we talked about earlier in our first webcast, we are -- the LCROSS mission is going to see if there is water in these specially shadowed regions on the Moon.

We need to pick a place in permanent shadow.

We need to pick a place near the poles because that's where we're seeing a lot of hydrogen.

Hydrogen is in water, H2O, hydrogen and oxygen.

We have to pick a place to impact and see it from the Earth.

There are a lot of different factors we have to go through and analyze where we impact.

We're also doing the type of work you're doing in the classrooms.

We're trying to characterize the impact when LCROSS hits the Moon.

So we and Pete will tell you about this as well, we're also doing experiments like you're doing in your classroom with different impactors and angles trying to see what size crater we create, how high the eject tiles go and how much is excavated from the impacts.

We're doing the same type of work you're doing.

We're very interested in seeing your results.

Other things we do also is we're characterizing the impacts to look at the science instruments that we have on our spacecraft.

We have instruments called spectrometers that will be looking at when you kick up ejectas.

We want to characterize it and we're tailoring our instruments so we can get data out of that.

We're doing some instrument work as well.

And we're also working with astronomers so that we can observe the LCROSS impacts both from the Earth from telescopes on Earth and also from telescopes that are in space.

So we do the science analysis to make sure that we can see those impacts and look at the ejecta, there are a lot of difference things we do on the science team and I'm happy Pete is here today so he can tell you more about the experiments which are closely related to the experiments the students have been doing that their classroom.


>> I do have a question here that's interesting.

Do you scientists ever get frustrated with your job?



>> Well, I wouldn't say I get frustrated with my job.

I would say that every day is different so every day you come in and there is a new science question that you have to figure out how to attack.

So in this example when we're looking at the impacts, we do the same type of thinking that the students are doing.

We have a science question and in this case the question is, what's the best angle of attack that we can impact at to get the most ejecta that is excavated during the impact?

We have to design and experiment and conduct the experiment and analyze the data to determine what the best result is and what the best angle of attack is in this case.

Sometimes it's interesting and it's difficult and it's hard.

You have to look at the data and try to understand what's happening but I think it's more exciting than frustrating.


>> We also have Dr. Peter Schultz from brown university here and he is a very renowned lunar scientists and he is going to be telling us a little bit about, what is it that you are doing as a scientist on this mission?


>> Well, what I'm really interesting in is exactly what you're interested in.

What happens when you hit something really hard?

This LCROSS gives us a chance to scale things up and really do a big splash.

We hope it's a big splash.

What I do for a living, in fact some of my students call me the master blaster, what I do for a living is that I slam things into things and I also go looking at different planets to see what big things have hit these planets and I go across the world to various sites just looking at what are the scars on the Earth to see what the craters look like.

Everywhere from experiments to the planets to the laboratory, that's where I go.

We even do models to see if we can make these things match.


>> That's interesting.

People often think of craters on the Moon or people have seen craters on Mars but you said you go and see craters here on Earth.


>> It's the best way.

When you look at a crater on a planet, you only get that two dimensional view.

The view from above.

If you look at craters on the Earth, you're actually looking below the surface because as erosion goes down through the crater you're really eroding away portions of it and you look inside so we get a brand-new perspective on how craters form.


>> That's fascinating.

Many of you have already interacted with Dr. Feldman in having your designs reviewed.

She's now going to talk to us a little bit about some of the designs she's taken a look at and the kinds of things that you folks out there are coming up with.


>> All right.


We've been very pleased with the preliminary designs that have come insofar and if you go to the Quest website you'll see there are comments on many of themselves.

There are themes that I want to bring up and thing we're seeing in the preliminary design that we can help with on the final design.

One of them, you want to make sure there is a distinction between when you're doing your experiment between the launch angle and then the impact angle which is the angle at which that protect isle hits your final service.

We're looking at the angle of impact.

The angle between the project aisle and when it hits the surface.

Think about ways to control the angle of impact and how you can measure that accurately to try to get the most ejecta hit out.

That was one thing.

Second thing to consider in your final design when you're doing your experiments to trying to come up with a good way to measure the amount of ejecta that's kicked out of the crater when it impacts.

We're looking to try to correlate the angle of impact.

The angle it comes in and hits that with how much stuff gets kicked out and so it's a tricky question and we won't tell you how to do it.

You'll have to think of it on your own.

This is what we do as scientists, design our experimental setup for the thing of interest.

How much ejecta or material is excavating or kicked out of your crater when that crater forms?

And another point when you submit your final designs for your final designs, you should actually have done the experiment so we would like to see not only the design but that you've actually completed the experiment.

You've built the rig, collected the data and send us that information.

In your final design send us your final data, send us pictures of you doing your experiments.

We'd like to get photographs of you with your rigs conducting the experiment and collecting the data.

We'll post the pictures online on the NASA website.

Doing the experiment is fun, too.

We have some pictures we can bring up of some of the classes that are doing their experiments.

Here is one here.

We have a group using marshmallows impacting into some flour and cocoa.

They designed the experiment and we can go maybe to the next photograph.

Here is another picture of another team building up their rig.

It has a little slingshot there doing your experiment.

Maybe one more.

Another one with a little catapult.

We've seen some slingshot and catapult-type designs.

Get out there and build your experiment and run it and collect the data.

Not only will it be scientifically interesting but see if you can have fun with it, too.

Your designs need to be safe.

So safety is the absolute number one concern.

Safety first.

Don't do anything -- even if you think you'll collect data.

If it's not safe, don't do it.

Have fun with it and we look forward to seeing your designs.

We also have some preliminary designs.

If we can look at.

We have one from a class.

They have a rubber band on the top.

A chute coming down, a marble comes out of the box, their lunar soil that they have acting as the Moon's surface.

There is a great deal of design and a lot of detail.

They can now construct it and run the experiment.

This is very similar to the experiments that Pete Schultz will tell you about in a second.

There is another one that's similar.

The next one a fifth grade science, the PVC puncher.

Well, we have several that are along the same lines of having a projectile coming out of a gun-like feature and you can change the angle of impact.

It was great to see some of these designs come through that are very similar to the experimental design we use at NASA as well.


>> Greg, do you have another design they can look at there?

Oh, okay.


>> So here was a third one.

This is a mounted slingshot and they're firing a ball directly at the target using rubber bands and they have a shaft out of which their projectile comes out using a steel ball to create a strong impact and they're varying the different impact angles from 50 to 70 degrees.

So they can vary the angle of attack that we were talking about before.

These are just a few examples of some of the designs.

Many of the other designs are already posted on the website and we'll talk about also how this is very similar to the vertical gun that Pete runs here at NASA.


>> Very good.

One of the things that you'll learn when you listen to Pete and jen talk and Jenn mentioned it several times they have fun with their jobs and hopefully one of the things you're discovering doing the experiments yourself is doing these experiments really is a fun thing to do and the difference is these folks get paid to do that.

So they've got pretty cool jobs.

Now, Jennifer was also mentioning something called the vertical gun.

Basically that is the test rig that we have here.

That's something that Pete works with very much so Pete, can you tell us a little bit about how NASA has gone about solving this problem, answering this question?


>> Sure.

Let me show you some pictures of the gun.

That's the best way to describe it.

This really is here at NASA Ames and what you're looking at is a really big ring about three stories high.

Let's go to the next step and I'll show you how big this really is.

This really shows three different views of the gun.

You notice that when it's in the up position, it's as you can see on the light, is over three stories high.

When we load the gun, when we actually get it ready to fire, we bring it down to the horizontal position and you see that in the upper left.

Now, that big blue thing, that's the impact chamber.

That's where we send the bullet or the sphere or the particle into the chamber and where we watch what happens.

Now, to launch this, this requires real dangerous material.

In fact, it involves both explosions and compressing hydrogen gas, both of those very dangerous.

Whenever we do these experiments we clear the room.

We aren't allowed in there at all.

That's how dangerous it is.

But the payoff is we get to watch it and you'll see the windows over there on the left-hand side and there are more windows on the right-hand side.

We cover each impact in all sorts of directions and we need to do that to be able to see what happens.

Now let's look at the next slide and we'll get a chance to see it in the loading position.

That's where we really work the gun to get it -- to put the projectile inside so we can fire it.

On the right is me along with two of my students, Carolyn and Clara.

They're getting ready to do some shots and look at what happens when the impact.

You see spectrometers seeing what sort of life is produced and what composition is released at the moment of impact.

Now you see the gun in a slightly elevated position.

This gun can go in different angles.

It goes from horizontal to 15 degrees to 30 degrees, to 45 degrees, 75 degrees and vertical.

It means we can keep the target flat while we do the experiments.

In the next time step we can actually see inside.

This is looking inside.

You can see somebody looking inside the chamber from the open door and on the lower right you're looking inside the chamber specifically and you see there is a lot of space.

I can walk in there and just stand up and do the work.

But the particles come through all the different ports slamming in right at the center.

It's important to have this chamber large because we want to be able to see what happens without interfering with the wall.

Let's take a look at see what happens.

In the next one we can see here we are on the left getting ready for the experiments and ka pow, this is what happens when we have the impact.

The debris coming out of the crater and the crater at the bottom right where we can see a small bullet, projectile.

It gives you a sense of how powerful this gun is.

It really moves.

Now let's take a look what happens if perhaps it doesn't look like you expect.

In the lower right that's -- it should look right but it's something you'll find out.

If you're able to capture the image it may look like a big mushroom, cauliflower.

That's not what it should look like on the Moon.

The question is why the difference?

Well, it turns out the difference is the one on the bottom was done in a vacuum.

The one at the top was done in atmosphere.

If you happen to have sand that's too fine it will look like a one on top.

If it turns out you have just the right size sand it will look like the one on the bottom.

In fact, doing the experiment with a slingshot just like what you guys are doing started me on a path of research that has taken about 30 years and I'm still doing the research.

It all started with the slingshot and doing the experiments.

We happened to get the wrong size sand and we got the cauliflower look thing at the top.

Let's go onto the next slide.

It gives you an idea of what happens when we look at this at real high frame rates.

This is looking at an impact of 10,000 frames per second, if you can imagine.

That means 10,000 frames.

It's going to take a long time to go through this but we speed it up.

The idea behind this is we slowed down everything so we pretend it's a science fiction movie where we can break it apart in stages.

What you see is the really high intensity, that flash that occurs is what we hope to see for LCROSS and we can see how the crater evolves with time.

I won't go into a lot of the detail.

You can look at it later on when it's posted but if you notice the ejected curtain, the debris looks like a wall of debris moving out.

We'll see this in a moment again.

The crater is inside that.

It really looks like a funnel and -- or maybe a lamp shade turned upside down.

Let's go on to the next one.

Now let's take a look at what happens if we really slam.

We'll keep the lights on.

Here is the crater forming and you see the ejector moving out.

If you do it in a vacuum or with large enough sand grains that's exactly what you'll see but you notice this is happening at pretty high speed.

This is the same speed that LCROSS will be going in at and we're doing the experiments just to vary the identity of the projectile like you're changing with marshmallows.

We'll be using hollow aluminum to understand the different debris we'll get from different altitudes.

Let's take another look from above.

Now you can look right down.

You can look inside the crater.

That's the amazing thing.

There isn't all that dust and stuff in the middle.

It actually looks like you can really look down inside.

This is the viewpoint that we will be seeing with LCROSS if the lights were on.

As you know from LCROSS, the lights won't be on so we need to do a different type of experiment to imagine what this is going to look like.

We'll show this in the next time step here.

In the next step we'll see what we did at the vertical gun range.

Here we see the gun all set up ready to go and I've broken it down to looking inside the chamber.

We put a light on the side and a wall so we could create a shadow.

What the wall is trying to do is be the same thing as if we happened to hit inside a crater or in the hidden by some mountains.

You can see with the ejector now coming above the shadow into the sunlight.

That's what we'll be seeing for LCROSS.

To give you an idea let's take a look again at this movie, this high-speed film and you saw this before but let's do it again.

Now you see the flash and then you see the ejector come up and it moves out.

This is the type of view we might be able to see from Earth but this is going to be so far away we won't see the detail.

But you can see that immediate flash and then you see the ejecta moving across.

It is quite beautiful.

Every time I see this I see something different.

I see something different now that I didn't know about.

Let's go onto the next.

Now let's see what it looks like coming down from above.

You see the flash and now you see that ejecta come into the sunlight.

Imagine yourself on the LCROSS spacecraft moving down going inside the ejecta and that's what we'll measure.

We'll measure the flash and then we'll see the composition of the gases released at the moment of impact.

It gives you sort of a sense of what is going on.

The question I've got is are we damaging the Moon?

How big is that crater?

Well the Apollo 16 astronauts went to a crater the same size in Arizona in the lower left.

That's about 1.2 kilometers across.

3/4 mile across.

If you look right down at the edge of that north crater for Apollo 16 there is a small crater.

That's just about the size of the LCROSS crater.

They actually examined the rim of the bigger crater so these things happen.

In fact, this happened very recently, last September.

Let's take a look at the next one.

I went down to see this one.

It was a new impact crater on earth.

A 50 foot crater found in Peru in September of last year about the same size as the LCROSS crater.

That's me right up at the rim.

We went out to look at this crater because we couldn't believe it happened but it did.

Nature throws us these curveballs all the time and why we need to check them out.

This was one of them.

You probably know, which is always happening on Earth anyway, how do you know?

Let's take a look.

In August in the next time spent, in August you get to see the meteor shower.

The Lynn den meteor shower you could see in November.

It was spectacular where they saw 2,000 meteors every second.

It was just amazing.

It looks like it was pouring rain but it was meteors.

They simply fall through like snowflakes come from comments and they disappear.

When you eat your Cheerios you're eating a little cosmic dust.

Let's go to the next slide and you can see one that made it to the ground.

This happened to hit in New York.

You'll see the car.

It dented the back end of the car and that car made it all the way around the world for people to see.

We see this fireball happening.

This was witnessed by people watching a football game.

Someone had a video camera ready and they watched it come through the atmosphere.

This is flaming.

It won't happen on the Moon because of no atmosphere.

These things will fly into the Moon undecelerated, not slowing down and slamming into it.

On Earth they slow down and the fragments can fall to Earth.

That's what happened in New York several years ago.

Let's go on to the next example and we'll see some simple craters, what we call simple craters.

The one many of you may be familiar with on the Earth is meteor crater out in Arizona.

A big hole in the ground and it is quite amazing.

If you even head toward the grand canyon take a right turn and go to the meteor crater.

In the upper left you see another crater four miles across and you get a chance to see.

Now, not all of them look like this but we'll look at bigger craters, the next slide.

And this is a crater in Canada that is around two miles across or so and that was formed around 1.4 million years ago and there is another one that is three miles across -- two miles across around 3.7 million years ago.

We see these craters but when you want to look at the bigger one it gets more complicated.

We look at these big craters on the Moon.

Next slide you can see these are called complex craters because they don't look like a craters that we produce in our experiments or the craters we produce in laboratory.

These look like they've had landslides that clear in the crater floor.

You can see -- you can barely see it but you can see it.

The other one is a complex crater both on the Earth and on the Moon.

The one on the lower right is TYCO that one you can almost see with a naked eye.

It was formed about 109 million years ago.

Dinosaurs roaming the Earth saw this crater flowing.

There would have been a meteor shower by the debris that fell to Earth at that time.

There is a crater in Canada with 120 kilometers across.

There is a lake that forms the ring.

That's not really the crater raim.

That's been completely removed by glacier and how we can look inside them with greater detail.

We get to dig down.

Let's get to the next one and see what happens when we look at a big crater.

This is a billion years old.

The primary crater throws out debris and they form secondary craters.

Those secondary craters some are five miles across.

When they hit they would have produced a Moon quake of a magnitude 7.

This one would have generated a Moon quack greater than anything we felt on Earth except for the big impacts.

You notice that ejecta blanket.

It is thrown out and lands near the rim.

We have bigger craters.

Now they get more complicated they begin to look large and that has a two ring and -- now, there are some of these basins on the Earth to remind you.

Let's go to the next and we can see the one that killed the dinosaur.

You see two views.

One view is on the surface where it barely can recognize it.

On the right you actually get to see what it looks like from below by using gravity and that horseshoe shaped structure.

This was a whopper.

After it all collapsed into the multi-ring, a complex crater almost 180 kilometers across.

After it finished forming it was 100 kilometers across.

Here are two different views of the Moon.

The first is Galileo's view of the Moon.

Now we see one side is cratered, the other side is covered up with lava.

How we look at them is controlled by the crater process.

If we look at the next time step we see the Moon as it evolved through time.

In the upper left is what the Moon probably liked like around 3.8 billion years ago.

You see the big, giant impact basin that's 400 miles across.

That basin forms the left eye of the man in the Moon or at some stages that looks like a lady sitting in a rocking chair and that would be where she's sitting.

That's that basin.

They are impact basins we can see with the naked eye.

The Moon was filled with lava but not all the craters finished forming.

You'll see that really bright crater.

If you look to the bottom you notice the craters hadn't formed yet.

We use these craters to tell time and we can tell the Moon was really just hammered with all these impacts and so was the Earth.

So now let's take a look at what we're going to be doing with LCROSS.

LCROSS will be hitting inside one of the biggest impact basins that's on the Moon.

It is 26 kilometers across.

1800 miles if you can believe this.

LCROSS if you go to the southern islands is where we will hit the permanent shadow and constant midnight.

We'll be hitting is right on the side of this huge basin that we can't see from the Earth.

Now you can see what it looks like from the other side of the Moon.

This was determined by the Clementine mission and the prospector.

That's a giant impact basin and we'll want to hit at the bottom as you see there.

Let me finish up with a brief look at what happens when you do change that impact angle.

Let's look at the next time set.

What we'll actually get to see is what happens when we shoot at an oblique impact angle.

The one in the laboratory is on top.

Some small oblique impacts the size of a football stadium on the Moon and the city-sized crater but they all have the zone of ejecta avoidance to the left.

I'm sure you'll see that when you do your experiment.

It has an effect on how much ejecta comes out and where it goes.

We have to optimize LCROSS to dig deep and get to the pay dirt which is hopefully the water or ice or water.

Next slide I just wanted to show you that there really are low impact angles and this one is MESSIA on the Moon.

It's what they look like when they get really low.

It gives you sort of this wrap-up, this tour of different planets and looking at impacts on the Moon, on the Earth and in the vertical gun range at NASA Ames.

I think that's the end of the slides, right?

Very good.

It gives you a sense of what I do for a living.

I get to go in there.

Every time I go into this gun I find something brand-new and it's why I go out.

I come out with my students because I want to find out what happens.


>> Wow, that's really exciting and one of the things we see here is that there is this great variety in craters.

They're very different.


>> Yes.


>> We're getting a lot of questions today.

We're getting a lot of questions coming in the chatroom and we should point out, because we're getting so many questions you will not see your questions there in the chatroom.

They are going into the moderation area.

But you are going to listen and hear many of your questions being answered.

One of the ones that we get fairly often is if we're going to really damage the Moon and break up the Moon by hitting it with LCROSS.

You mentioned how the LCROSS crater is going to be about 60 feet across but you talked about another impact that is 1800 miles across?

That kind of maybe gives us a clue as to what might happen.


>> The Moon survived the huge impact.

It was a big asteroid.

If the Moon survived that, not very well.

It fractured more than 50% of the Moon.

If it survived that I think it will survive our puny little LCROSS mission.


>> We don't count for much that way.



>> No.


>> We are trying to launch a lot of material so that we can measure what it is made of.

Jen, how much material do we think might get excavated or thrown out of this.


>> We're expecting on the order of 250 metric tons of material to be excavated in that plume that we'll then analyze for the shepherding spacecraft and telescopes on the Earth and in space.


>> Very good.


>> A question, we're getting quite often actually is how are they going to observe the ejecta.

The question is if you can't see it firsthand, how are you going to get the information you're looking for?


>> That's a very good question.

On our shepherding spacecraft, it will actually fly right through that ejecta.

So the pictures that Pete was showing you, our spacecraft will fly through it and we have nine instruments on that spacecraft.

We have a visible camera that can see invisible light.

We have two near infrared cameras, two mid infrared cameras looking at heat and we have instruments called spectrometers that we can identify water, elements, other minerals.

We have two -- we have a foughtometer that will allow us to see the flash which happen at the beginning before that ejecta cloud comes up.

We have all the instruments that are on the spacecraft and we'll beam that data back to Earth here at NASA Ames and we'll be able to analyze the data.

In addition, we'll also have telescopes on the ground, on Earth that are also watching the impact so they will be collecting data and will be analyzing that and there are also telescopes in space.

They'll also be pointing their telescopes at the Moon during the LCROSS impacts and collecting data that way.

We have a whole different range of instruments and observing platforms that we'll be looking at the LCROSS impact.


>> That's probably a very interesting point.

This material that we want to study and find out what it's made of, as a scientist you won't be able to get it in the laboratory to see what it's made of.

You've designed instruments so you can analyze this remotely.


>> Exactly.

We -- me as the person, I don't have to go to the Moon to figure out what the Moon is made of.

We've designed this mission and these experiments like Brian just said so we can remotely send our spacecraft there, collect the data and send the data back to us here on Earth.


>> I have a question here from I believe it's freedom.

It's is this a simulation?

I'm assuming they're talking about either what you are doing with LCROSS or what they're doing in the classroom.

It is a little hard to know.

The idea is testing models here on Earth, I think, versus what's really going to happen with LCROSS.


>> The simulations that you do are really very similar to what we do in the laboratory.

You will see the ejecta come up and you'll notice that ejecta that comes from the bottom will end up near the rim.

And that's one of the reasons why LCROSS is zooming in following the first sent car as it goes in because you want to get as close as you can to see the material.

These are simulations, they aren't exact.

We have to adjust and that's why we go to school, this is why we try to learn the proper equations to allow us to adjust.

And that's why we do them.


>> Great.

Sunshine II has an interesting question.

If the Moon is being constantly hit by impactors why can't we study the ejecta from these craters?


>> You want to take that?


>> I would love to.

That's a really good question.

We are.

We're beginning to.

For a long time scientists didn't even think we would see any impact on the Moon but I actually have determined that there are about 24 impacts per year formed on the Moon that's the same size as the LCROSS crater.

So let's think about that.

We only see one side.

That means about 12 impacts every year will form a crater about 20 meters or about 50 feet across.

So this means that they are occurring.

We can't see the ejecta but we can see the flash and people are looking at the flash to understand it.

The next step we'll be able to try to look for the ejecta.

The difficulty is everything happens very quickly.

And because of that, you have to be looking at the right place at the right time.

Now, as we get better with these instruments we can probably do that.

However, what's unique about LCROSS is we're controlling the experiment just like you do on your experiments and on the gun.

We're controlling what it's made out of, how fast it's going.

It will be able to control that experiment and different from a natural impact which we don't even know when it will hit exactly and we don't know where it will hit exactly.

For LCROSS we know where it will hit, when and what it's made out of.


>> We'll be able to have the telescopes ready looking at the right place at exactly the right time.


>> Great.

Another question about LCROSS.

How deep will the crater hit into the Moon?


>> I'll take that.

It will probably form a crater, the crater itself will probably be somewhere around three to four meters deep.

300 or 400 yards, if you will.

However, not all of that will be thrown into the air.

When you do experiments if you try any of this you'll find out that some of the materials push down.

So one of the tricks that we're trying to do is make sure we understand.

It won't go too deep but deep enough to get down to the place where we think there is the area of ice or whatever is carrying that hydrogen we'll be able to find that out.


>> That's interesting when we're setting up a place to live on Earth.

If you set up a new home somewhere often one of the things people will do is dig a hole and look for water.

They dig a well that's pretty deep oftentimes.

We won't be digging that far deep down.

Only like 9 to 14 feet or something like that.


>> If you've tried to dig one of those holes it's deep and it takes some time.


>> I apologize the question came -- I know I should be letting you know who is asking the question.

The templeville students would like to know.

When the cratering object hits the Moon and the -- will it be buried under the surface?


>> I get to take that one.


>> You want to take it?


>> We'll tag team.

So when we have the impact of the upper stage of the rocket which is the first impactor, simulations to date predict it will probably crumble and be there on the Moon.

It's not very big so it will still be in that crater that it forms in this region of permanent shadow.


>> We have a feeling based on what happens when you go this speed.

When you do your experiments you'll be able to pick up your projectile unless you use the marshmallows and that's how fast you go.

I have to tell you, I've done some crazy things in my life.

One of the things I did was launch some eggs.

I wouldn't recommend this but we launched eggs and we launched a raw egg.

That is going to behave similar to what is going to happen with the LCROSS spacecraft.

It will hit and smash to smithereens.

The shell will go to the bottom of the crater.

Some of the crater will cover up the pieces, other pieces will fly out.

They'll form very small fragments.

That gives you a sense if you try to throw a B.B. or a marble into the sand it will survive.

If you throw an egg into the sand it won't.


>> It sounds like a good experiment to do.


>> It's a mess.


>> Something else important to note is that the LCROSS impactor is the upper stage of our Moon rocket.

But when it gets to the Moon it is going to be empty.

We'll make sure that all the fuel is gone outside of that and it will take months to make sure we open up the tanks and let any of the remaining fuel out before it hits the Moon.

So that when it hits the Moon we want to make sure that any gases we detect came from the Moon and not something that we brought along with us.

That means that what ends up getting left on the surface of the Moon is going to be this metal shell and none of those chemicals that were in there to begin with.


>> Good question.


>> I'm going to ask that folks please don't put questions in about when you're going to answer my question because it makes it very hard to find the real questions in here.

I have a question from BODWA.

Does the mass of the impactor change how much ejecta comes out?


>> Ooh, that's a really good question.

In fact, it does.

The amount of ejecta that comes out it is directly related to the size or the mass of the projectile.

I hope you try that experiment and find out.

You can do it yourself.

If you design your experiment you can determine how much mass comes out for every mass.

You change the mass and find out.

This is a good product but I'll tell you right now -- it does depend.

If you try that and then try taking that egg, taking out the yolk and throw the empty shell you'll find out something different.


>> Okay.

Steven from Clayton high asks if we do find water on the Moon how will we decide who it belongs to and who can use it?


>> Jen, that's yours.


>> That's a really good question.

Right now the reason we have this mission is for exploration purposes because NASA and international partners are talking about returning back to the Moon and that includes robotic spacecraft and people back to the Moon.

One of the big questions that LCROSS is aiming to answer, is there water ice there near the poles of the Moon that people could actually use once we go back to the Moon?

You can use water for many different things, not just drinking or taking a bath.

You can break apart the hydrogen and oxygen and it's what rocket fuel is made out of.

You have the resource on the Moon that you can use instead of having to ship everything from Earth which as you can imagine putting everything on a rock earth and shipping it from Earth is expensive and difficult.

You live off the land how we explored Earth when we use the resources that are there.

It is an international collaborative effort for the return to the Moon and many different countries are working together for the robotic missions and for planning out the human architecture missions to go there.

So it's a shared resource and there is a lunar Moon treaty also saying that it's a shared commodity.


>> A question, why can't we use the ejecta from craters that are already there?


>> It's similar to the--


>> I think demi is probably asking why can't we use the ejecta from the craters that might have water in them.

There are a series of space crafts going to the Moon and will be looking at some of the craters there to see whether or not there is anything.

The trouble is, when you -- unless it's a really fresh impact, that water -- any water that might be there would probably escape.


>> So if we look on the surface of the Moon.

The Moon has no atmosphere and it doesn't have air.

On the surface of the Moon is very dry.

If you put water on the surface of the Moon it will escape and go away.

The surface of the Moon is very dry.

If you have an impact even if there was water in the crater and the ejecta settled on the lunar surface it would dry out.

By looking at the older craters and ejecta we can't really tell if there was water ice down below.

When we explained the LCROSS impact we need to look at the ejecta right away when it's happening before the water dries up, escapes, goes away and we need to look at the fresh impact crater we're forming.


>> Good question.


>> We have quite a few questions from Dublin sells middle school trying to have us help them solve the issue of angle.

And I guess they all sum up in what angle did you find would work best?

I'm not sure we want to give that answer.


>> I'm not going to--


>> That's like knowing the answer.

I wouldn't call it cheating but I can tell you this, let me tell you something really important is that the most common impact angle on the Moon is not straight down.

And, in fact, a straight down impact is as rare as an impact that comes in sideways.

So the most probable impact is going to be 45 degrees.

But I'm not -- you're going to have to find that one out for yourself.

It's -- you almost got us but not quite.



>> I think some of that has to do with how much advantage there is to testing models on Earth again and disadvantages, advantages and whatnot.

We have one here that I as an educator like and it says what high school courses would you recommend in order to work for NASA?


>> Well, I took every science class and math class that was available in high school so I took Earth science and biology and chemistry and physics and math and algebra, trying nom try, and also in college.

I was interested in math and science so I took a lot of physics, astronomy and geology and all sorts of different science classes that I could.

So I'd say if you're interested in math and science, continue to take those classes.

The math is very important as well.

Up through higher level math courses.


>> I would also comment.

NASA is very big and many ways to work for NASA.

I followed a similar path.

I was a lunatic when I was in third grade.

I just loved the Moon.

This is what I wanted to do with the rest of my life and I was lucky to do it.

I took the classes but I also took art.

I was going to become an artist and that was really difficult.

It turns out very important to be able to visualize things especially through for geology.

There are many ways to work for NASA.

One way is to go the physics and astronomy side or other people who deal with design.

To design the habitat that the astronaut is going to live.


>> We're getting near the end here and I think there is a great question here that maybe ties into the next steps after the challenge and that is, will our impactor makes a difference that the naked eye can see?


>> The LCROSS impactor?

We're doing simulations just like you're doing to determine how much ejecta there will be and how long it will take to settle out and how bright it will be.

We expect that if you have a 10 to 12 inch size telescope you should be able looking at the Moon when the impact is happening and we'll tell you on our website when it's happening that you should see the impact.

If you want to observe them you can do that from your backyard if you're able to see the Moon at the right time from your local science museum.

From your local planetarium.


>> We like to encourage you, if you do have a telescope, to please take it out and go look.

We know some people have cameras that they put on their telescopes.

If you're able to do that take pictures of this.

If you get pictures, please share them with us.

We would be very, very interested to have as many views of this event as we can get.

Remember, we've never done this before.

This is very new and so the more data we get, the more information, the better.

That's also something we should emphasize is that there is no bad data.

Whatever result we get here is going to be very interesting.

You can help us discover what that result is.


>> I probably should add, they probably won't be able to see the crater.

The crater will be in shadow.

Even if it were in daylight it's too small to see with a telescope.

There is one way to do it, with radar.

It takes a huge, huge radar instrument.


>> What we're looking to see is that plume, that material that will come up from the surface of the Moon and into the sunlight and that could be really interesting to watch.

So we hope that this is encouraging you to continue with your designs.

Continue with your testing and please send us those results and we'll post them on our website.

Also, remember that as you started this you took a survey.

At the end of this process, there is a post challenge survey.

We want to make sure that you take that and get that information to us so that we can see all the things that are being learned through this exciting process.

Thank you very much for participating.

Thank you Dr. Heldmann and Dr. Schultz for this wonderful, wonderful introduction here to LCROSS and the cratering process on the Moon.

Continue your work and we look forward to finding out what you've learned.

Thank you.

 FirstGov  NASA

Editor: Linda Conrad
NASA Official: Liza Coe
Last Updated: October 2008