Encyclopedia vs Heliosphere

Explore the Solar System, its planets and the worlds beyond Earth. Read 386 articles, search for a topic, and save discoveries to revisit. START WITH FIVE FREE ARTICLES New readers can choose any five different articles. Your chosen articles stay unlocked, and revisiting them never uses another choice. Existing readers keep previously granted access. MAKE DISCOVERIES YOUR OWN • Search article titles and full text • Follow links between related topics • Save articles and return to your reading position • Continue recent reading and track your progress • Explore connections through the timeline and graph • Find article sources and image credits inside the app CHOOSE YOUR ACCESS Own the full encyclopedia with a one-time purchase for complete offline reading. Or choose monthly or annual Premium for the full encyclopedia plus AI chat grounded in this subject's articles. Eligible new Premium subscribers receive a three-day introductory trial. Subscriptions renew automatically unless canceled through your App Store account. Current local prices and terms appear before purchase. Restore Purchases recovers eligible previous purchases. Earlier full-version ownership includes encyclopedia and offline access; Premium AI requires a subscription. Internet access is required for AI chat and purchases. AI answers may contain errors; consult the linked sources. Article text is derived from Wikipedia. Images come from appropriately licensed Wikimedia Commons and other open sources. Source links, licenses and credits are available in the app. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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.