# SDO Viewer vs Project Planet Space

The clearest difference is rating: Project Planet Space at 5.0 against SDO Viewer's 2.7. SDO Viewer's advantage is update cadence (every 2 months vs every 25 months) and ratings volume (6 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Project Planet Space holds the better App Store score, 5.0 against 2.7. That said, the two scores are not equally well evidenced: SDO Viewer has 6 ratings behind it against 1, so its average is the more settled of the two.

SDO Viewer ships an update every 2 months, Project Planet Space every 25 months. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | SDO Viewer | Project Planet Space |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.7 (6 ratings)](https://appshunter.io/ios/app/sdo-viewer/id913723111/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/project-planet-space/id6499347273/reviews)** |
| Number of ratings | **6** | 1 |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 25 months |
| Monetization | Free | Free |
| Size | 6 MB | 2 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jérôme Diaz](https://appshunter.io/developer/334987620) | [Miroslav Hanzelka](https://appshunter.io/developer/1653768748) |

## What reviewers say

### SDO Viewer

[App page](https://appshunter.io/ios/app/sdo-viewer/id913723111)

Access and view the latest images from the Solar Dynamics Observatory. Receive push notifications when new images become available, keeping you updated on solar activity.

**Highlights:** Download SDO images, Display latest solar images, Push notifications for new images, Courtesy of NASA/SDO science teams

**Features:** macOS Compatibility

**In-app purchases:** none


### Project Planet Space

[App page](https://appshunter.io/ios/app/project-planet-space/id6499347273)

Explore our solar system with an interactive map. Discover planetary gravity, temperatures, and atmospheric data. Calculate your weight on other worlds and learn fascinating space facts.

**Highlights:** Interactive solar system map, Personalized weight and age calculations, Detailed planetary data widgets, Multi-language support, Metric/Imperial unit switching, Cosmic museum aesthetic, Real astronomical data integration

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SDO Viewer free?

SDO Viewer is free to download, with no in-app purchases.

### Is Project Planet Space free?

Project Planet Space is free to download, with no in-app purchases.

### Which has better reviews, SDO Viewer or Project Planet Space?

Project Planet Space is rated higher. SDO Viewer averages 2.7 out of 5 from 6 ratings, while Project Planet Space averages 5.0 from 1 ratings.

### Do SDO Viewer or Project Planet Space have ads?

Neither SDO Viewer nor Project Planet Space shows ads.

### Which is updated more often, SDO Viewer or Project Planet Space?

SDO Viewer ships an update every 2 months, and Project Planet Space every 25 months. Most recently, SDO Viewer was updated on November 1, 2026 and Project Planet Space on November 4, 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.*