First Impressions

When I first saw some of the spring 2024 releases, #42179 Planet Earth and Moon in Orbit immeditately caught my imagination! I absolutely love the idea of playing with an Orrery to see how the Earth rotates around the Sun, but have never had the chance to play with one. The idea of building one using LEGO Technic pieces is very compelling. I am especially curious to see how close to the real 365-day rotation this model is able to achieve using existing parts. I’m also curious to see if it can be easily motorized.

Box Contents

My copy included paper bags, which is becoming increasingly common this year, especially for sets produced in Europe. (Pre-review sets are almost always produced in Europe, even though I am located in North America.)

• Box Size: 38 × 25.9 × 9.2 cm (15 × 10 1/4 × 3 5/8”)
• Box Weight: 1022 g (2.3 lbs)
• Part Count: 526 pieces
• LEGO Parts Weight: 551.2 g (1.21 lbs)
• Weight-per-piece: 1.05 g/piece
• Price per piece: $0.143 per piece
• Price per gram: $0.136 per gram.
• Numbered bags/stages: 4
• Pieces per stage (average): 132 pieces.

#42179 Planet Earth and Moon in Orbit features prominent LEGO Space packaging.

Box contains 4 numbered bags, an un-numbered bag, some loose parts, instruction booklet and stickers.

• Bag 1: 1x extra-large paper bag (26×23 cm) marked 6488955 / 349S3.
• Bag 2: 1x large paper bag (23×21 cm) marked 6488949 / 548S3.
• Bag 3: 1x large paper bag (26×20 cm) marked 6488953 / 449S3.
• Bag 4: 1x large paper bag (26×19 cm) marked 6488947 / 548S3.
• 1x large un-numbered plastic bag containing:
  • 2x printed earth hemispheres (with Northern and Southern Hemisphere printing)
  • 2x Ø11 Frame, Round (Part 77107) in 199Dark Stone GreyDark Bluish Gray
  • 4x 56mm D. × 14mm Technic Wheel w/ Tire, Axle (Part 39367) in 26Black.
• 1x large un-numbered plastic bag containing:
  • 2x Ø11 Hemispheres (part 4413) in 191Flame Yellowish OrangeBright Light Orange
  • 2x Ø15 Frame, Round (Part 3250) in the new 402Reddish Orange color.
• 1x large 144-page instruction booklet with glued spine. 27.0 x 19.2 cm (10 5/8 x 7 5/8”).

Build Process

Bag 1 requires the four large Technic wheels and the first of the two Ø15 Round Frame parts. We begin by building a solid cross-shaped base that sits on the four wheels which are being used on their side for their skid-resistance instead of their ability to roll. The cross-shape is wobbly until we install four 11×11 35-Tooth ¼ Gear Ring (Part 24121).

Sturdy base resting on four Technic wheels.

After this, we build a rectangular sub-assembly containing gears, which is the first part of the complex mechanical systems that make this brick-built orrery work.

First set of gears in place at the end of Bag 1.

The Second Bag completes the base and lower mechanisms. This involves a number of additional gears to step down the rotation speed. This involves a sub-assembly containing additional gears that slides into place in the middle.

Sub-assembly containing even more gears.

Near the end, we attach a crank to one side, which allows us to see how power from the crank is transfered pretty quickly to a central rotating axle (upon which I expect the sun will attach and rotate), as well as the very slow rotation of a 60-tooth Turntable on the top which I anticipate the armature suppoting the Earth will attach to. If ever there was a testament to my enthusiasm for this set, I actually applied the stickers labeling each month to the reddish-orange ring. I hate stickers but concede that they are appropriate in this context.

A solid base with a crank on left side.

Continuing to Bag 3, it is time to build another complex gearbox and the armature where the Earth and Moon will eventually be attached. I was surprised by how much additional gearing is included within the armature, which we learn at the end of this bag causes not only the earth and moon to spin, but also for the sun itself to spin.

Getting ready to install the armature.

We attach the armature, followed by two more curved white panels on the sides that are also used to strengthen the model. Finally, we add the sun itself to the top of the model in the final step.

Attaching the Sun at the end of Bag 3.

This leaves just one more bag to complete the model. Bag 4 is all about a final sub-assembly which we will attach to the armature from the following bag. This one is pretty complex as well, with mutiple gear ratios employed to allow the earth to rotate very quickly on it’s axis while the moon rotates quite slowly around the earth. We have another ring with stickers showing the phases of the moon, and another pearl gold part pointing to the current phase.

The final assembly is ready to attach.

After attaching it, there’s just a few steps remaining to strengthen the connection, and it’s play time! It is an absolute joy to use it for the first time, with each crank of the lever causing the earth to rotate several times, while the moon rotates slowly around the earth and the sun rotating on it’s own axis at about the same speed as the moon.

Completed Model (with stickers — a rarity in my house.)

Build time: 81 minutes. (Bag 1: 18 minutes, Bag 2: 18 minutes, Bag 3: 18 minutes, Bag 4: 27 minutes. Build time does not include the time to apply stickers)

Value

Value is complicated to assess, so I’ll offer just two ways of thinking about value with this set. On the first hand, there’s the learning value of this set which is very high. Even just a very cusory online search shows that you can get a pre-built Sun and Moon Orbit model for about 40$ on Amazon. I would argue that the additional learning opportunities associated with actually building the model are worth the higher price.

As for our more objective measures of value such as price-per-part and price-per-gram, this set is atrocious. It has the second worst price-per-gram that we have measured and a comparably poor 14.3 cents per part.

Conclusion

This set is just one of eight LEGO Technic sets that are being released on March 1, 2024. We just received a huge stack of these sets and will review as many as we can in the weeks to come!

The seven other March 2024 LEGO Technic Sets.

March 2024 LEGO Technic Lineup:

• #42179 Planet Earth and Moon in Orbit (This set)
  526 pieces, ages 10+, $75, available March 1 at LEGO.com
• #42180 Mars Crew Exploration Rover
  1599 pieces, ages 11+, $150, available March 1 at LEGO.com
• #42181 VTOL Heavy Cargo Spaceship LT81
  1365 pieces, ages 10+, $110, available March 1 at LEGO.com
• #42178 Surface Space Loader LT78
  435 pieces, ages 8+, $35, available March 1 at LEGO.com
• #42171 Mercedes-AMG F1 W14 E Performance
  1642 pieces, ages 18+, $219, available March 1 at LEGO.com
• #42165 Mercedes-AMG F1 W14 E Performance Pull-Back
  240 pieces, ages 7+, $27, available March 1 at LEGO.com
• #42169 NEOM McLaren Formula E Race Car
  452 pieces, ages 9+, $50, available March 1 at LEGO.com
• #42170 Kawasaki Ninja H2R Motorcycle
  643 pieces, ages 10+, $85, available March 1 at LEGO.com

While I have not built them all yet, I feel comfortable saying that this set will be one of the best because it explores a completely new topic for an official LEGO Technic set. That’s because almost every LEGO Technic set is based on a vehicle of some kind — a pure mechanical machine is a really unusual offering in the theme. I think this is a great thing — this set has the potential to introduce a lot of new builders to LEGO Technic!

This is an excellent set which would earn our very highest marks if it weren’t for the issue of value. It unfortunately scores near the bottom of our rankings in both price-per-part (which I expected would be poor) as well as price-per-gram. This is our most objective way of measuring value in LEGO sets, and I can not give a perfect rating to a set that is so obviously overpriced.

It’s really helpful to have an interactive model when trying to understand the orbits of the Earth and the Moon.

Despite the poor value, #42179 Planet Earth and Moon in Orbit easily earns our Excellent (4/5 star) rating. If you can find it for 20% off, it’s a must have in my book.