Solar Sphere vs Astro PM
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Solar Sphere
Monitor real-time solar activity with Kp-index data and high-resolution solar images. Understand geomagnetic disturbances and their impact on Earth's magnetic field. Ideal for drone pilots needing to check conditions before flying.
- Real-time Kp-index monitoring
- High-resolution solar images
- Kp-index explanation
- Geomagnetic storm indication
- Drone flying safety guidance
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The Solar Sphere provides current value of Kp-index derived from the NOAA Space Weather Prediction Center using data from multiple ground-based magnetometers. Also, current solar images are available in 4 different high resolution formats. The Kp-index quantifies solar disturbances in the horizontal component of earth's magnetic field with an integer in the range 0-9 with 1 being calm and 5 or more indicating a geomagnetic storm. For drone flyers, please only fly on solar KP Index less than 5.
Astro PM
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Astro PM is the companion app to the Astro PM desktop software — the astrophotography project manager that plans, schedules, and automates your imaging through NINA. Pair the app with your Astro PM account and your observatory follows you everywhere. PAIR IN SECONDS Scan the QR code shown in the desktop app (Settings → Pair Phone), or enter your sync token manually. Your connection is stored securely on the device. YOUR IMAGING SYSTEMS AT A GLANCE See every enabled rig — site, telescope, and camera — with live target counts. Multi-observatory setups show each dome or pier as its own system, exactly as configured on the desktop. TARGETS AND PROGRESS Browse the cloud targets for each imaging system with their images, coordinates, mosaic layout, and status. Tap a target for its full exposure plan: per-filter progress bars, exposure length, gain, offset, binning, and accepted counts — plus total integration time captured versus planned. Priorities and progress stay in sync with the desktop app and the NINA plugin. ASTRONOMICAL WEATHER A 16-day astronomical forecast for each observing site: cloud cover by layer, computed seeing and transparency, wind, temperature and dew point, and sun/moon altitude bands with your imaging windows marked. Nights are centered so you can judge tonight at a glance. NINA REMOTE PAUSE/PLAY Running the Astro PM NINA plugin? Pause and resume your automated nightly imaging loop right from your phone — the sequencer confirms back so you know the command landed. BUILT FOR THE FIELD Target data is cached on the device, images download once and stay cached, and nothing polls in the background — the app only fetches when you open or refresh a page. REQUIREMENTS Astro PM is a companion app. It requires the Astro PM desktop application (Windows) and an Astro PM account — visit astro-pm.com to get started. NINA remote control additionally requires the free Astro PM NINA plugin. This app is free to use and does not offer or have any in-app purchases. Weather data by Open-Meteo. Satellite and forecast sources credited in the desktop app.
Screenshots
Verdict
The clearest difference is update cadence: Astro PM at fortnightly against Solar Sphere's every 9 months. Solar Sphere's advantage is device support (4 vs 2) and iOS requirement (9.0 vs 15.0). On price, ads and in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.
Solar Sphere ships an update every 9 months, Astro PM fortnightly. The most recent releases landed on October 17, 2026 and October 18, 2026 respectively.
| Parameter | Solar Sphere | Astro PM |
|---|---|---|
| Price | Free | Free |
| Rating | 4.1 (7 ratings) — better | — |
| Positive reviews | 44.4% of reviews | — |
| Number of ratings | 7 — better | — |
| Update frequency | Every 9 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod, Apple Watch — better | iPhone, iPod |
| Requires iOS | 9.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 3 MB | 49 MB |
| Age rating | 17+ | 4+ |
| Developer | Pulsely Consulting | Josh Jones |
In-app purchases
Solar Sphere
No in-app purchases
Astro PM
No in-app purchases









