Solar System Clock vs Heliosphere
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Solar System Clock
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See the positions of all planets in our Solar System based on the current date. Or, you can set your own custom date to see the alignment of our planets from a future date or a past date. You can use this app to find out the best time to watch a planet in the sky by finding out when it will be closest to Earth.
Heliosphere
Explore a real-time 3D simulation of the solar system, planets, moons, and spacecraft using accurate astronomical data. Learn about celestial bodies and space missions with educational content and quizzes.
- Real-time 3D solar system simulation
- Live spacecraft tracking
- Deep sky exploration
- Comprehensive astronomy education
- Time travel from 1900 to 2100
- Planet-centric viewing mode
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Explore the solar system at your fingertips. Heliosphere is a real-time 3D solar system simulation powered by NASA JPL Horizons data. It accurately recreates the orbits of planets, moons, comets, and dwarf planets while tracking the real positions of active spacecraft. * Real-time 3D Solar System Simulation — 8 planets, 5 dwarf planets, 10+ moons, and 4 comets — Precise Keplerian orbit calculations based on real astronomical data — Time travel from 1900 to 2100 — Pan, zoom, and rotate for a free-roaming perspective — Switch to planet-centric viewing mode * Live Spacecraft Tracking — Voyager 1, 2 | Pioneer 10, 11 — Cassini | Juno | New Horizons | Parker Solar Probe — Real position data from NASA JPL Horizons API * Deep Sky Exploration — Over 150 bright stars — 530 Milky Way stars — 124 deep-sky objects (Messier, NGC/IC catalogs) * Comprehensive Astronomy Education — 6 difficulty levels from middle school to graduate — Core concepts: Kepler's Laws, gravity, escape velocity, and more — Mission timelines for Voyager, Cassini, New Horizons, and others — 60+ quiz questions to test your knowledge — Historical space event date-guessing challenges * Free for Everyone — All content available at no cost — No ads — 11 languages supported Experience the beauty of the cosmos and the wonder of science through scientifically accurate data and intuitive interaction.
Screenshots
Verdict
The clearest difference is in-app purchases: Solar System Clock at none against Heliosphere's 3. Solar System Clock also leads on iOS requirement (16.6 vs 18.0). On price, update cadence, 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. Heliosphere sells 3 one-off in-app purchases. Solar System Clock asks for nothing beyond the download.
Solar System Clock ships an update every 2 days, Heliosphere every 3 days. The most recent releases landed on August 15, 2026 and August 28, 2026 respectively.
| Parameter | Solar System Clock | Heliosphere |
|---|---|---|
| Price | Free | Free |
| Rating | — | 3.0 (2 ratings) — better |
| Positive reviews | — | 50.0% of reviews |
| Number of ratings | — | 2 — better |
| Update frequency | Every 2 days — better | Every 3 days |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | — | Free |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, Vision Pro |
| Requires iOS | 16.6 — better | 18.0 |
| Further details — not scored | ||
| Size | 5 MB | 36 MB |
| Age rating | 4+ | 4+ |
| Developer | Mateusz Andrzejczuk | CHUNGKIL KIM |
In-app purchases
Solar System Clock
No in-app purchases
Heliosphere
- 1 Coffee$2.99
- 3 Coffees$8.99
- 5 Coffees$14.99





