Mars Birthday Cake (It's Out of This World)

Mars Birthday Cake (It's Out of this World)

My daughter wants to be an astronaut and go on a mission to Mars. So it was only natural that her birthday cake should reflect that goal!

We decided to make a Mars themed birthday cake with the planet on it!

We wanted the cake to accurately reflect the surface of Mars and depict the present and possible hardware on Mars. Taking some artistic license, of course ;-)

I have included some Mars information tidbits. (From NASA, Wikipedia and other sites.)

They are loosely related to the Instructable steps, just for fun.

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Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, being larger only than Mercury. In English, Mars carries the name of the Roman god of war.

Spherical Cake Pan (Wilton 3D Sports Ball Pan - Aluminum 2 piece, 6 inch)

Cake Mix - White 'Standard' two layer (+ Eggs, Oil, Water, etc)

Frosting - Vanilla Buttercream (Butter, Vegetable Shortening, Powdered Sugar, Milk, Vanilla, Salt)

Rice Krispies Treats (Rice Krispies, Marshmallows, Butter)

Black Fondant

Edible Decorative Silver Stars

Food Coloring

Vodka (For airbrushing; Oh, an airbrush helps with this)

3D Printed spacemen, rovers, Mars Buggy, etc.

Toothpicks

Some type of base - I used an upside down jelly-roll pan covered in aluminum foil

Prepare the cake mix as directed on the package. My daughter loves pink, so we divided the cake mix batter into three batches and colored them in two shades of pink and one of purple.

Grease and flour the baking pans per the instructions. We wanted an interesting looking interior to the cake so we spooned dollops of cake mix alternating colors into the pans.

Set the half spheres onto their holding rings (included with cake pans) on a baking sheet and bake per instructions.

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Traveling to Mars the Astronauts leave the protection of the Earth's magnetosphere and as such are exposed to much more radiation than astronauts in low earth orbit, such as on the International Space Station. Radiation includes low dose-rate galactic cosmic rays (GCR) and to intermittent solar particle events (SPEs). When the sun is more active it's larger magnetic field helps provide greater shielding from cosmic rays, but the greater solar activity increases the solar particle output hazard. Interplanetary Space is a tough place to travel in.

Let the cakes cool after coming out of the oven. Remove them from the pans and then put them in the freezer to further cool them and to freeze them solid to help provide greater strength while frosting.

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The temperature in Space near the earth is +248 degrees Fahrenheit in sunshine to -148 degrees Fahrenheit in the shade. On Mars average temperature is -80 degrees Fahrenheit (Yes, minus 80). Extreme temperatures happen at the poles, -195 degrees Fahrenheit, and near the equator, +70 degrees Fahrenheit on a summer day (Sounds like you might almost want to visit the equator).

Even though space is a giant void we decided to fill it -- with Rice Krispies Treats. It is a Birthday cake after all.

Prepare the Rice Krispies Treats and form them into a large rectangular block.

Cover the Krispies base with black fondant. To cut the fondant without trying to cut the foil we played around with a pizza cutting wheel - who knew, it worked pretty well.

Randomly sprinkle the silver edible stars over the blackness-of-space fondant.

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Space is a vacuum so there is not really much of anything there. Not much matter (a few atoms here and there), no air, pretty darn empty.

Place the the frozen half-spheres on a turntable to facilitate frosting. 'Glue' the halves together with frosting. Apply a 'crumb coat' of frosting to seal in the crumbs and make a base to frost upon.

Reserve a bit of frosting to write 'Happy Birthday' with later in preparation.

Mix up the surface-of-Mars-colored frosting. I looked as maps/photos of Mars to try to get a color match. I probably should have gone darker, but this worked and let me add darker colored features on top of this base color. In hindsight I also could have put more red into the color mix. Apply the colored frosting to the Mars cake.

I tried to include some surface features - I made an attempt at Olympus Mons and Valles Marineris.

I added some white frosting to the polar cap to represent the water and CO2 ice.

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The Martian polar caps contain frozen water and also frozen carbon dioxide (solid CO2, dry ice). In fact, dry ice snow falls on Mars.

Mars holds the record for the largest/tallest mountain, Olympus Mons ( 374 miles in diameter [about the size of Arizona] and 16 miles high) and one of the longest/deepest valleys, Valles Marineris or Mariner Valley, (2,500 miles long [it would stretch across the continental United States] and 4 miles deep).

I wanted to airbrush features onto the cake so I frosted the bottom of a cake pan to act as a test canvas to practice my airbrush skills (or lack thereof) on.

Mix the food coloring with vodka to get the shade of color you want. You want the high alcohol content of the vodka so it will evaporate and leave the color behind. The mixture must be a very thin liquid (almost water like) to work well in the airbrush. I looked at a map of Mars and tried to create the corresponding darker regions on the cake.

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Mars has an abundance iron oxide on the surface. This iron oxide (rust) gives Mars' its reddish color.

3D print the 'equipment' you are going to 'send' to Mars. I found 3D files for Mars Rovers, Astronauts, and the Moon Buggy (Which I 'repurposed' for Mars ;-) on Thingiverse. The pink astronaut is, of course, my daughter - the lover of all things pink!

Paint details on the astronauts, like their visors, and on other equipment.

The larger items I drilled holes into their bottoms and inserted toothpicks to hold them to the cake.

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Mars has only a thin atmosphere, and not something you want to breath. So you will need a space suit. Earth's atmosphere is 78% nitrogen and 21% oxygen. Mars' atmosphere consists of 96% carbon dioxide and less than 2% each of argon and nitrogen.

As noted, Mars has an atmosphere but there is not much of it. Air pressure on Mars is very low. Only 0.6% of that on Earth. (0.087 psi vs 14.69 psi)
Just like our Moon, Martian gravity is less than that on Earth, but not as little as our Moon's. On Mars you experience 62% less gravity. If you weighed 100 lbs on Earth you would weigh 38 lbs on Mars.

You have arrived. The cake is almost done. You need to carefully remove the Mars cake from the turntable and place it on the rice krispies treat platform. I did not provide anything structural to help mount the Mars to the platform, only applied frosting between Mars and platform.

Apply the astronauts, rovers and other equipment at various locations on the Martian cake. I also placed some equipment on the fondant as the void of space just looked too void. Don't forget to write "Happy Birthday" on the base with the frosting you set aside.

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The closest Earth and Mars approach each other is 34 million miles. It takes 687 days for Mars to orbit the Sun. Since the Earth orbits the Sun in only 365 days the Earth, during its orbit, is catching up with Mars and then passing it as they both make their way around the Sun. The trip to Mars can vary, but the shortest would be about 7 months each way.

It was a lot of work but it was worth it!

What a cool cake (irrespective of space temperatures).

My daughter loved it!

Enjoy!

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Reaching and returning from Mars would be a great accomplishment. Especially since it is very technologically challenging to do. After reaching Mars we would explore it. Some suggest that the first astronauts would explore Mars for about 3 months before returning.

There is no way the cake would last anywhere that long!