Moon Book vs Real Solar System
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Moon Book
This app visualizes lunar eclipses, showing viewing times and directions from your location. Plan your observations by setting specific locations and previewing eclipse phases.
- Lunar eclipse viewing times
- Direction of eclipse visibility
- Location-specific eclipse phases
- Pre-set observing locations
- Overseas eclipse start times
- Thumbnail images of eclipse phases
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The Moon Book App clearly shows you when and from which direction eclipse of the moon can be viewed. The time of beginning or ending penumbral eclipse is simultaneous around the country but a place of beginning total eclipse differs from pace to place. The Moon Book will show you the phases of the moon eclipse at your place. You will be able to set up any observing place beforehand if the moon eclipse star chart is selected. When you move to a distant place for observing the moon eclipse, you will be able to know in advance a place where the Earthfs shadow starts hiding the moon. You will be able to check a start time of the moon eclipse overseas also. Tapping on the moon icon at the upper left corner of the star chart will show you thumbnail images of the phases of the moon eclipse at regular intervals. The interval of the thumbnail images can be changed.
Real Solar System
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This solar system simulator reflects actual planetary position information. When the app is launched, the sun is positioned 20 cm in front of the device, based on the device's position. Around it, the eight main planets of the solar system and the celestial body to be observed orbit. The orbits are displayed as if they were trajectories. The position of each planet is calculated based on actual values. # Features - x] Realistic solar system with ARKit - x] Orbits of the 8 planets are displayed. - x] Planets are realistic textures imported from USDZ files. - x] Planet positions are calculated based on real values (using Horizons API) - x] The object to be observed can be changed. - x] Display of the orbit of the object of interest - x] Calculate the position of the target object based on actual values (using the Horizons API). - x] Adjustable speed (minus value for reverse rotation) - x] Zoom function (zoom in/zoom out) - x] Toggle the display of the text information and the coordinate axis (New!) ## How to use 1. when you launch the application, you will be asked for "permission to use camera" at the first startup. If you allow it, an ARKit session will start. 2. 2. a coordinate axis will be placed 20 cm in front of you, based on the device's position. 3. Tap the "Load Planet" button to load the planet model. Just wait a moment. 4. The 8 main planets of the solar system and the object to be observed will orbit around it. 5. Move the device to observe the solar system from various angles. 6. Tap the buttons at the bottom of the screen to adjust the speed and zoom. 7. You can change the object to be observed from the menu in the upper right corner of the screen. 1. Halley's Comet 2. Hayabusa2 & Ryugyu 3. Voyager 1 & 2 4. New Horizons & Pluto 5. Cassini (New!) 6. OSIRIS-REx & Bennu 7. Comparison of Circle and Ellipse 8. Geocentric theory (New!) 8. Toggle the display of the text information and the coordinate axis from the menu in the upper right corner of the screen. (New!)
Screenshots
Verdict
The clearest difference is update cadence: Real Solar System at monthly against Moon Book's every 6 months. Moon Book's advantage is iOS requirement (12.0 vs 17.6). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Moon Book ships an update every 6 months, Real Solar System monthly. The most recent releases landed on October 9, 2026 and October 24, 2026 respectively.
| Parameter | Moon Book | Real Solar System |
|---|---|---|
| Price | Free | Free |
| Rating | — | 1.0 (1 ratings) — better |
| Positive reviews | 90.0% of reviews | — |
| Number of ratings | — | 1 — better |
| Update frequency | Every 6 months | Monthly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 22 MB | 302 MB |
| Age rating | 4+ | 4+ |
| Developer | Vixen Co.,Ltd. | Masaya Nagaoka |
In-app purchases
Moon Book
No in-app purchases
Real Solar System
No in-app purchases
Questions
Is Moon Book free?
Is Real Solar System free?
Do Moon Book or Real Solar System have ads?
Which is updated more often, Moon Book or Real Solar System?
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