# Celestia vs Discover Mars

The clearest difference is rating: Discover Mars at 5.0 against Celestia's 4.4. Discover Mars also leads on in-app purchases (none vs 4) and review sentiment (100% vs 79%). Celestia's advantage is ratings volume (339 vs 12) and update cadence (fortnightly vs monthly). On price, ads and device support there is nothing between them.

Both are free to download. Celestia sells 4 in-app purchases, starting at $0.99 per 7 days. Discover Mars asks for nothing beyond the download.

Discover Mars holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: Celestia has 339 ratings behind it against 12, so its average is the more settled of the two. Written reviews point the same way: 79% of Celestia's written reviews are positive against 100% of Discover Mars's.

Celestia ships an update fortnightly, Discover Mars monthly. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Celestia | Discover Mars |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (339 ratings)](https://appshunter.io/ios/app/celestia-space-simulator/id1500434829/reviews) | **[5.0 (12 ratings)](https://appshunter.io/ios/app/discover-mars/id1550710909/reviews)** |
| Number of ratings | **339** | 12 |
| Positive reviews | 78.9% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Fortnightly** | Monthly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 550 MB | 8 MB |
| Requires iOS | 16.0 | **13.0** |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [林峰 李](https://appshunter.io/developer/1186547508) | [Manthan B Thakkar](https://appshunter.io/developer/1550710911) |

## What reviewers say

### Celestia

[App page](https://appshunter.io/ios/app/celestia-space-simulator/id1500434829)

Explore the universe in real-time 3D. Visit planets, moons, star clusters, and galaxies, viewing them from any point in space and time. Customize your experience with expandable content and detailed simulations.

**Highlights:** Real-time 3D space visualization, Explore planets, moons, stars, galaxies, Accurate solar system object positions, Interactive planetarium mode, Expandable content with add-ons, Customizable celestial databases

**Features:** Game Controller support, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Celestia PLUS (Weekly) | $0.99 | per 7 days |
| Celestia PLUS (Monthly) | $1.99 | per month |
| Celestia PLUS (Yearly) | $19.99 | per year |
| Celestia PLUS (Lifetime) | $79.99 | one-time |

**What reviewers like**

- ⭐ Realistic space simulation
- 🌌 Ability to explore galaxies and star systems
- 🔍 Detailed planet and moon textures
- 📷 Great for taking screenshots
- 🤖 Reminds users of Space Engine

**What reviewers complain about**

- 🐛 Occasional crashes and glitches
- 🌌 Limited exploration beyond Milky Way and Andromeda
- 🌍 Flat terrain on planets
- 🔍 Lack of detail on some celestial objects
- 🔒 Paywall for some features

**Reported bugs**

- Milky Way and other galaxy textures not loading properly
- Crashes when using certain add-ons
- Issues with planet and moon orbits not being accurate

**Requested features**

- Add more exoplanets and distant star systems
- Implement terrain generation for planets
- Expand to include more galaxies and the overall universe structure
- Add support for black holes, pulsars, and other exotic objects
- Improve controls and camera movement


### Discover Mars

[App page](https://appshunter.io/ios/app/discover-mars/id1550710909)

Explore stunning, high-definition images captured on Mars by NASA rovers. View the latest photos, zoom in for detail, and learn fascinating facts about the Red Planet's atmosphere, gravity, and temperature.

**Highlights:** View latest Mars rover images, Slideshow mode for full-screen viewing, Zoom into high-definition photos, Save images to your device, Explore Mars' atmosphere, gravity, and temperature

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Celestia free?

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

### Is Discover Mars free?

Discover Mars is free to download, with no in-app purchases.

### Which has better reviews, Celestia or Discover Mars?

Discover Mars is rated higher. Celestia averages 4.4 out of 5 from 339 ratings, while Discover Mars averages 5.0 from 12 ratings.

### Do Celestia or Discover Mars have ads?

Neither Celestia nor Discover Mars shows ads.

### Which is updated more often, Celestia or Discover Mars?

Celestia ships an update fortnightly, and Discover Mars monthly. Most recently, Celestia was updated on October 29, 2026 and Discover Mars 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.*