# Planetary Clock vs Heliosphere

The clearest difference is price: Heliosphere at Free against Planetary Clock's $0.99. Heliosphere also leads on update cadence (every 3 days vs every 27 months). Planetary Clock's advantage is rating (4.9 vs 3.0) and in-app purchases (none vs 3). On review sentiment, ads and device support there is nothing between them.

Heliosphere is free to download; Planetary Clock costs $0.99 up front. Heliosphere sells 3 one-off in-app purchases. Planetary Clock asks for nothing beyond the download.

Planetary Clock holds the better App Store score, 4.9 against 3.0. That said, the two scores are not equally well evidenced: Planetary Clock has 34 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 57% of Planetary Clock's written reviews are positive against 50% of Heliosphere's.

Planetary Clock ships an update every 27 months, Heliosphere every 3 days. The most recent releases landed on August 19, 2026 and August 28, 2026 respectively.

## The numbers

| Metric | Planetary Clock | Heliosphere |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[4.9 (34 ratings)](https://appshunter.io/ios/app/planetary-clock/id812876503/reviews)** | [3.0 (2 ratings)](https://appshunter.io/ios/app/heliosphere-solar-system/id6757491622/reviews) |
| Number of ratings | **34** | 2 |
| Positive reviews | **57.1% of reviews** | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 27 months | **Every 3 days** |
| Monetization | Paid | **Free** |
| Size | 14 MB | 36 MB |
| Requires iOS | **11.4** | 18.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Vision Pro |
| Age rating | 4+ | 4+ |
| Developer | [Piotr Knapczyk](https://appshunter.io/developer/1541886746) | [CHUNGKIL KIM](https://appshunter.io/developer/960187999) |

## What reviewers say

### Planetary Clock

[App page](https://appshunter.io/ios/app/planetary-clock/id812876503)

Visualize the precise positions of all planets in the Solar System for any given day. It uses accurate NASA data for orbital calculations and relative planet sizing, offering a clear, educational view of celestial mechanics.

**Highlights:** Real-time planet positions, Accurate orbital calculations, Uses NASA data, Relative planet sizing, Educational solar system view

**Features:** macOS Compatibility

**In-app purchases:** none


### Heliosphere

[App page](https://appshunter.io/ios/app/heliosphere-solar-system/id6757491622)

Explore a real-time 3D simulation of the solar system, planets, moons, and spacecraft using accurate astronomical data. Learn about celestial bodies and space missions with educational content and quizzes.

**Highlights:** Real-time 3D solar system simulation, Live spacecraft tracking, Deep sky exploration, Comprehensive astronomy education, Time travel from 1900 to 2100, Planet-centric viewing mode

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Coffee | $2.99 | one-time |
| 3 Coffees | $8.99 | one-time |
| 5 Coffees | $14.99 | one-time |


## Frequently asked questions

### Is Planetary Clock free?

Planetary Clock costs $0.99, with no in-app purchases.

### Is Heliosphere free?

Heliosphere is free to download, with in-app purchases available.

### Which has better reviews, Planetary Clock or Heliosphere?

Planetary Clock is rated higher. Planetary Clock averages 4.9 out of 5 from 34 ratings, while Heliosphere averages 3.0 from 2 ratings.

### Do Planetary Clock or Heliosphere have ads?

Neither Planetary Clock nor Heliosphere shows ads.

### Which is updated more often, Planetary Clock or Heliosphere?

Planetary Clock ships an update every 27 months, and Heliosphere every 3 days. Most recently, Planetary Clock was updated on August 19, 2026 and Heliosphere on August 28, 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.*