# SDO Viewer vs Mars Today

The clearest difference is rating: Mars Today at 5.0 against SDO Viewer's 3.0. Mars Today also leads on review sentiment (100% vs 60%) and update cadence (monthly vs every 2 months). SDO Viewer's advantage is iOS requirement (13.0 vs 15.2). On price, ratings volume, ads and in-app purchases there is nothing between them.

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

Mars Today holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 5 and 4 respectively. Written reviews point the same way: 60% of SDO Viewer's written reviews are positive against 100% of Mars Today's.

SDO Viewer ships an update every 2 months, Mars Today monthly. The most recent releases landed on June 1, 2026 and June 11, 2026 respectively.

## The numbers

| Metric | SDO Viewer | Mars Today |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (5 ratings)](https://appshunter.io/ios/app/sdo-viewer/id913723111/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/mars-today/id1640335599/reviews)** |
| Number of ratings | **5** | 4 |
| Positive reviews | 60.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Monetization | Free | Free |
| Size | 6 MB | 4 MB |
| Requires iOS | **13.0** | 15.2 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jerome Diaz](https://appshunter.io/developer/334987620) | [James Buckhouse](https://appshunter.io/developer/1631924321) |

## 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


### Mars Today

[App page](https://appshunter.io/ios/app/mars-today/id1640335599)

Access the latest images of Mars from NASA's Curiosity rover. Browse current photos or explore past images from Curiosity, Spirit, and Opportunity by SOL. Bookmark and share your favorite discoveries.

**Highlights:** Latest Mars images from Curiosity, View past images from Spirit and Opportunity, Browse by Mars SOL, Bookmark favorite images, Easy sharing functionality, No login required

**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 Mars Today free?

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

### Which has better reviews, SDO Viewer or Mars Today?

Mars Today is rated higher. SDO Viewer averages 3.0 out of 5 from 5 ratings, while Mars Today averages 5.0 from 4 ratings.

### Do SDO Viewer or Mars Today have ads?

Neither SDO Viewer nor Mars Today shows ads.

### Which is updated more often, SDO Viewer or Mars Today?

SDO Viewer ships an update every 2 months, and Mars Today monthly. Most recently, SDO Viewer was updated on June 1, 2026 and Mars Today on June 11, 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.*