# Moon Book vs Real Solar System

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.

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.

## The numbers

| Metric | Moon Book | Real Solar System |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[1.0 (1 ratings)](https://appshunter.io/ios/app/real-solar-system/id6475644962/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 90.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Monthly** |
| Monetization | Free | — |
| Size | 22 MB | 302 MB |
| Requires iOS | **12.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Vixen Co.,Ltd.](https://appshunter.io/developer/536188843) | [Masaya Nagaoka](https://appshunter.io/developer/1698240335) |

## What reviewers say

### Moon Book

[App page](https://appshunter.io/ios/app/moon-book/id906552724)

This app visualizes lunar eclipses, showing viewing times and directions from your location. Plan your observations by setting specific locations and previewing eclipse phases.

**Highlights:** 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

**Features:** Vision Pro support

**In-app purchases:** none


### Real Solar System

[App page](https://appshunter.io/ios/app/real-solar-system/id6475644962)

**In-app purchases:** none


## Frequently asked questions

### Is Moon Book free?

Moon Book is free to download, with no in-app purchases.

### Is Real Solar System free?

Real Solar System is free to download, with no in-app purchases.

### Do Moon Book or Real Solar System have ads?

Neither Moon Book nor Real Solar System shows ads.

### Which is updated more often, Moon Book or Real Solar System?

Moon Book ships an update every 6 months, and Real Solar System monthly. Most recently, Moon Book was updated on October 9, 2026 and Real Solar System on October 24, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*