Your Own Terrestrial Planet Without Atmosphere

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Introduction: Your Own Terrestrial Planet Without Atmosphere

This a simple classroom or science at home project that has a good edutainment value even at primary school level.

The Science Part
Mercury, Venus, Earth and Mars are called terrestrial planets as these have 'land' to stand-on.  We may also add moon to the list. Lunar and Mervury surfaces are highly cratered. These craters were formed about 4 billion years ago when the solar system was just born (about 0.3 byr ago) and taking it's present shape.  At that time there were large number of small bodies flying in the solar system and naturally colliding with the other planets. 

The gaseous planets like Jupiter, Saturn, Uranus and Neptune simply swallowed these debris. But on terrestrial planets these missiles left their mark in the form of a craters. 

On planets like the Earth, Venus and Mars most of these makes were eroded by changing weather on these planets.  Whereas Mercury and Moon, which have little atmosphere, have retained their poke marks. 

Thus - if one goes exploring planets of other suns and come across a planet which has highly cratered surface then it is quite likely that the planet has little or no atmosphere.

Study of these features on the planets has helped astronomer to get insight into how the surfaces of these planets have evolved over a period of time.

The Fun Part
---->>>> begins from the next step

Step 1: DIY Surface of a Planet Without an Atmosphere

For this project we required

A) Quick setting Plaster of Paris ( POP )  available in the hardware shops. Cost of 5 k.g. POP (about 1 USD).
( POP  is a white powder that, when mixed with water to form a paste, will turn hard in a few minutes. POP is made by heating gypsum, a mineral composed of calcium sulfate and water. )

B) A cardboard box tray  of 20 x 20 x 5 cm. Normally 8 inch pizza comes in a box of this size.  We need only one side of the box 

C) 250ml cup - a Styrofoam cup will do. 

D) A white sheet of paper (standard wall calendar will do).

E) A vessel to mix POP.

F) A pair of rubber gloves (for every player)

Also a few sheet of newspapers, scotch or paper tape to stick the sides of the pizza box if needed.
 

Step 2: POP Mix

We now mix POP and water -

You may have to make a few trial before arriving at your own formula.
 
Take two full measures of POP (D) is taken on a sheet of paper. And Three measures of plain water in a big broad pan (E).

Mix POP from (D) into water in (E).  This operation has to be carried out quickly. To make smooth paste, while mixing POP to the water one needs to keep stirring the mixture and avoid formation of lumps.

Once all of POP is poured in the water and smooth slurry is make, pour the mixture in the tray (A). It is OK to have a few bubbles in the mixture.  These will be the craters.

Step 3: Make Your Own Craters

To make more craters sprinkle or spray water with your fingers on this still unset mold.

You may also drop a few larger droplets using a dropper.

Step 4: It Is Done Now

We are now almost done. Allow it to dry.

It would help to spray a little amount of water to slow down drying. This will avoid formation of cracks.

After the surface has dried completely take it out of the cardboard box and mounted or placed.

Step 5: What Next - 1

You could also let the surface dry unevenly generating cracks and valleys.

You may add a bit of red or brown colour or rouge (ferric oxide) to POP.
Surface of Mars has ferric oxide on it to get it a reddish hue.

And never mind if your mixture becomes too lumpy.

Here is what you can do -- make some mountains on the planetary surface.

Every child will have his or her own piece of land. You may even ask children to name the features on the planet.

Step 6: What Next - 2

More science

You can ask the students to study the craters and tell you what do the infer?

There are large and small size craters.  Some craters on top of the other - indicating those were formed later.

You may also add little extra water to slow down setting of POP and thenuUsing a standard dropper - put drops from different heights.
A drop from higher height will make larger crater. What does that tell us?

How about dropping a small stone -

Variations could be many -

And children love this project - slushy - muddy clay to play with too.



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27 Comments

My own project, which I need a hand with, is displayed here:

http://www.wikihow.com/Etch-Your-Own-Crater? The 10kV spark generator is my missing ingredient, so Instructables please step forward with a design!

I suppose you could put Bicarbonate of soda in the mix for it to create random craters.
It would be interesting to see what it looks like.

Fantastic suggestion - thanks very much. I will try later this week - I am traveling -

You're very welcome.
As a film maker it's quite tempting to see how realistic one can re-create the Apollo 11 landing.
Obviously the conspirisists will go crazy if I'm successful.

Just as a 4 yr late update. I met a S.African who knew that a studio 'hanger' was built in SA exactly before the Apollo 11 Moon shot. No doubt this was the NASA insurance policy as featured in Capricorn 1.

You know, when I saw the photo for this instructable, I thought it was an astrophoto instructable. It looks uncannily like some of my webcam moon photos (attached)!  The color and texture are good.  Great work!

One difference is that your craters have less of a flat bottom than a lot of the larger moon craters.  Any idea why?

Video4-un_pp.jpgmoon.jpg

Physics does not scale very well in this particular field...
See, if a meteor crashes into our moon, a lot of debris is thrown not only outwards, but also upwards (as you can see it if you dump a heavy stone into water). As gravity pulls it down, it gets spread a little bit... And there is the key: The height compared to the gravitational force is different if you do it bigscale on the moon and smallscale on the earth.

Also on the moon the craters filled up by the millenias of small but constant solar winds... From time to time particles get pulled off the surface and travel a few feet before they fall into a depression and get trapped for another millenia. The bigger the depression the more trapping-effect it has. And a sizeable crater is quite a depression. :)

The Key difference would be material, I'd assume. While this is a fantastic simulation of the formation of a planet (btw, I am definitely going to use this for my 8th grade astronomy class this year), it is just a simulation. There are different forces at work for a large object like the moon being hit at tremendous speeds by an asteroid. The energy released from an impact of an asteroid will usually partially heat up and melt the surface that is hit, especially during the moon's early stages when it was forming and the thin crust was still cooling off. Also debri is usually thrown up and brought back down by gravity. Plaster on the other hand, hardens as it dries out instead of cooling off.

The difference is part material and part scale. Your photo resembles very small craters seen on the moon, while also looking like larger craters found on the moons of Saturn which are made of ice instead of rock. I'm sure that if your instructions are followed on a much larger scale then the craters will look more lunar. I've also gotten Marslike craters by adding a bit too much water.

nice project.. but just for the record recent studies have shown that the moon was created more than 5+ billions years ago.. moon rocks were dated at 5.3 billion years old, and the dust upon which they were resting was at least another billion years older.