Comparison

Project Planet Space vs Heliosphere

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Project Planet Space

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
Read full description

Project Planet - an interactive map of our solar system How much would you weigh on Jupiter? Why does a day on Mercury last longer than its year? Project Planet turns space facts into a fingertip-sized journey. Scroll through all nine planets (Pluto included), feel each world's pull on your own body, and explore the numbers astronomers have spent decades collecting. Highlights - Sticky scroll across the system: from Mercury to Pluto, each planet stays centred long enough for you to take it in. - You, on every world: enter your weight and age once and watch them recalculated by each planet's gravity and orbital period. - Five rich widgets per planet: surface temperature with reference markers (Antarctica, freezing, boiling), atmospheric pressure with composition chart, travel times from Earth from walking up to the speed of light, gravitational force with everyday objects (phone, backpack, car), and an interactive pressure simulator with phase changes for water, oxygen, CO2, hydrogen, nitrogen and mercury (Antoine equation under the hood). - Six languages: Czech, English, German, Slovak, Spanish and French, auto-detected from your device. - Metric or imperial: switch instantly; weights, temperatures and distances follow your preference. - Crafted to feel like a small cosmic museum: dark cosmic theme, hand-tuned typography, subtle scroll choreography, and a right rail that lets you jump to any planet. - Built on real data: gravitational accelerations, orbital periods, NASA mean temperatures, atmospheric compositions and substance phase transitions. Requires an internet connection. The app runs as a continuously updated webview and uses native iOS capabilities such as haptic feedback to add a tactile dimension to your interstellar journey.

About

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.

Highlights
  • 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
Features
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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

Project Planet Space4 screens
Heliosphere4 screens

Verdict

The call

The clearest difference is rating: Project Planet Space at 5.0 against Heliosphere's 3.0. Project Planet Space also leads on in-app purchases (none vs 3) and iOS requirement (15.0 vs 18.0). Heliosphere's advantage is update cadence (every 3 days vs every 25 months). On price, ratings volume, ads and monetization model 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Heliosphere sells 3 one-off in-app purchases. Project Planet Space asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Project Planet Space holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

UpkeepUpdate frequency

Project Planet Space ships an update every 25 months, Heliosphere every 3 days. The most recent releases landed on October 27, 2026 and October 24, 2026 respectively.

Scorecard4 real differences · 6 level
Project Planet Space versus Heliosphere: the parameters behind the verdict, then further details
ParameterProject Planet SpaceHeliosphere
PriceFreeFree
Rating5.0 (1 ratings) — better3.0 (2 ratings)
Positive reviews—50.0% of reviews
Number of ratings12 — better
Update frequencyEvery 25 monthsEvery 3 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, Vision Pro
Requires iOS15.0 — better18.0
Further details — not scored
Size2 MB37 MB
Age rating4+4+
DeveloperMiroslav HanzelkaCHUNGKIL KIM

In-app purchases

None

Project Planet Space

No in-app purchases

3 purchases

Heliosphere

One-time3
  • 1 Coffee$2.99
  • 3 Coffees$8.99
  • 5 Coffees$14.99

Questions

Is Project Planet Space free?
Project Planet Space is free to download, with no in-app purchases.
Is Heliosphere free?
Heliosphere is free to download, with in-app purchases available.
Which has better reviews, Project Planet Space or Heliosphere?
Project Planet Space is rated higher. Project Planet Space averages 5.0 out of 5 from 1 ratings, while Heliosphere averages 3.0 from 2 ratings.
Do Project Planet Space or Heliosphere have ads?
Neither Project Planet Space nor Heliosphere shows ads.
Which is updated more often, Project Planet Space or Heliosphere?
Project Planet Space ships an update every 25 months, and Heliosphere every 3 days. Most recently, Project Planet Space was updated on October 27, 2026 and Heliosphere on October 24, 2026.

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