Celestia vs Discover Mars
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Celestia
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.
- 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
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Celestia — real-time 3D visualization of space 3D Space Simulator | Celestia lets you explore our universe in three dimensions. Celestia simulates many different types of celestial objects. From planets and moons to star clusters and galaxies, you can visit every object in the expandable database and view it from any point in space and time. The position and movement of solar system objects is calculated accurately in real time at any rate desired. Interactive Planetarium | Celestia serves as a planetarium – for an observer on any celestial object. You can easily navigate to any world and land on its surface. When used as a planetarium, Celestia shows accurate positions of solar system objects in the sky. You can switch labels and other supporting features on and off with hotkeys, or zoom in and out on an object of interest, for example Jupiter’s system of moons. Expandable Content | Customize Celestia according to your needs. Celestia’s catalogues can be easily expanded. There are many different add-ons available containing new objects like comets or stars, high-resolution textures of Earth and other well mapped solar system bodies, as well as 3D models for asteroids and spacecraft on precise trajectories. Even fictional objects from well-known sci-fi franchises can be found. EULA(End User License Agreement): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Discover Mars
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.
- 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
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The Discover Mars app provides easy access to images taken on Mars by the NASA Mars rovers. - View the latest images taken on Mars by the Perseverance, Curiosity, Opportunity, and Spirit rovers. - Tapping on a photo launches it in slideshow mode to view the full high-definition image. You can double-tap to zoom into a photo or tap on the Share icon to save images directly onto your iPhone. - The Mars tab provides interesting visuals about Mars, such as its atmosphere, gravity, temperature, and much more. Designed by Spencer Everett Developed by Monte Thakkar
Screenshots
Verdict
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 (338 vs 12) and update cadence (fortnightly vs monthly). On price, ads 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. 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 338 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 27, 2026 and October 24, 2026 respectively.
| Parameter | Celestia | Discover Mars |
|---|---|---|
| Price | Free | Free |
| Rating | 4.4 (338 ratings) | 5.0 (12 ratings) — better |
| Positive reviews | 78.9% of reviews | 100.0% of reviews — better |
| Number of ratings | 338 — better | 12 |
| Update frequency | Fortnightly — better | Monthly |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 16.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 550 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | 林峰 李 | Manthan B Thakkar |
Customer experience
Celestia
Discover Mars
Bugs and requests
Celestia
Reported bugs
3 issues- 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
5 requests- 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
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Celestia
- Celestia PLUS (Weekly)7 Days trial$0.997 Days
- Celestia PLUS (Monthly)$1.991 Month
- Celestia PLUS (Yearly)$19.991 Year
- Celestia PLUS (Lifetime)$79.99
Discover Mars
No in-app purchases









