Best Astronomy Apps 2026: SkySafari, Stellarium and What Each One Is For

Astronomy apps split into three distinct categories with almost no overlap in function. Conflating them — using a planetarium app when you need a weather forecast, or using a star-chart app when you need telescope control — is how you end up with five apps that collectively fail to do what one correct app would do well.

This guide covers each category, the best app in each, and when free options are sufficient.

App	Price	Platform	Purpose
SkySafari 7 Pro	~€15	iOS/Android	Planetarium + mount control
Stellarium Mobile Plus	~€14	iOS/Android	Planetarium alternative
Star Walk 2 Plus	~€5/yr	iOS/Android	Casual sky identification
Clear Outside	Free	iOS/Android	Astronomical sky forecast
Clear Dark Sky	Free	Web/iOS	Seeing and transparency
Light Pollution Map	Free	Web/App	Bortle zones and dark sites

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The Three Categories

Planetarium and star-chart apps — Show you what is in the sky right now, identify objects by pointing your phone at them, and help you plan what to observe. These are the apps most people think of when they say “astronomy app.”

Telescope control apps — Connect via Bluetooth or WiFi to a GoTo mount and control where the telescope points. Only relevant if you own a GoTo mount.

Sky condition and weather apps — Tell you whether tonight is worth observing: cloud cover, transparency, seeing, and astronomical darkness. Underused by beginners and essential for everyone.

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Category 1: Planetarium and Star-Chart Apps

SkySafari 7 Pro — iOS/Android (~€15 one-time)

SkySafari is the professional standard for handheld planetarium software. The Pro tier includes a database of 27 million stars (to magnitude 18.6), 740,000 galaxies, and complete solar system objects. The Milky Way rendering is the most accurate on any mobile platform. Object descriptions are written by astronomers rather than product writers — the entry for M57 includes the Ring Nebula’s distance, central white dwarf temperature, and expansion rate.

The key SkySafari advantage over alternatives: telescope control. SkySafari connects directly to most GoTo mounts (Celestron, Sky-Watcher, Meade, iOptron) via the mount’s serial interface, allowing you to tap a target in the app and have the telescope slew to it. For GoTo mount owners, this feature alone justifies the price.

Augmented reality (AR) mode overlays constellation lines and object labels on the live camera feed — useful for quick identification, less useful as a primary observing tool.

SkySafari 6 Plus (~€5) is the middle tier: 19 million stars, less object detail, telescope control for most mounts. Adequate for most visual observers who do not need the full database.

Who it’s for: Serious visual observers and GoTo mount owners. The best single astronomy app available.

Price: ~€15 (Pro) / ~€5 (Plus), one-time purchase

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Stellarium Mobile Plus — iOS/Android (~€14 one-time)

Stellarium is the best-known open-source planetarium software, and the mobile Plus version brings its desktop quality to phone. The rendering engine is excellent — horizon, atmosphere simulation, and Milky Way rendering match the Stellarium desktop experience. Object database covers 1.7 million stars in the basic version, expandable with catalogue plugins.

Stellarium’s advantage over SkySafari: the landscape and atmosphere rendering is more immersive. For visual beauty and orientation — understanding how the sky relates to the horizon from a specific location — Stellarium is the better experience. The plugin ecosystem allows importing custom catalogues (double stars, exoplanet hosts, variable stars) that SkySafari’s fixed database cannot match.

Telescope control is available but less mature than SkySafari’s implementation.

The free version (Stellarium Mobile) covers most basic stargazing needs without payment. Recommended as a starting point before deciding whether Plus is needed.

Who it’s for: Observers who want desktop-quality rendering on mobile, and those who need custom catalogue imports.

Price: ~€14 (Plus) / Free (standard), one-time purchase

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Star Walk 2 Plus — iOS/Android (~€5/year subscription)

Star Walk 2 is the most accessible entry point: a clean interface, immediate AR identification, and minimal configuration. Point your phone at the sky, see labels. Tap a star, get a fact card. The experience is designed for casual engagement rather than systematic observing.

The astronomical content is accurate but shallow. Object descriptions are brief. The database covers bright objects adequately but thins out at the faint end. Telescope control is absent.

Who it’s for: Beginners learning to identify constellations and bright objects, and non-observers who want a casual sky identification tool without a learning curve. Not the correct choice for anyone planning systematic observing sessions.

Price: Free (limited) / ~€5/year (Plus), App Store / Google Play

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Category 2: Telescope Control Apps

If you own a GoTo mount: SkySafari 7 Pro (€15) or SkySafari 6 Plus (€5) covers all major mount brands.

If you own a Sky-Watcher GoTo mount specifically: SynScan Pro (free, Sky-Watcher’s official app) handles full GoTo control via WiFi dongle. Less feature-rich than SkySafari but free and officially supported.

If you own a Celestron GoTo mount: Celestron StarSense Explorer app (free) works with StarSense Explorer telescopes. SkySafari works with all Celestron mounts.

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Category 3: Sky Conditions — The Most Important Apps Nobody Uses

These apps are more operationally important than planetarium apps for anyone who observes regularly. There is no point setting up a telescope on a night with 40% transparency and poor seeing.

Clear Outside (free, iOS/Android)

Clear Outside is the UK Met Office atmospheric data rendered into astronomy-specific forecasts: cloud cover by hour, transparency (a measure of atmospheric clarity, not just cloudlessness), seeing (atmospheric turbulence, rated 1–5), wind speed, and astronomical darkness windows. Covers European and North American locations.

A night can be clear (no clouds) but have poor transparency (high humidity, atmospheric particulates) or bad seeing (jet stream overhead). Clear Outside shows all three independently. This is the first app to check before an observing session, every session.

Price: Free

Clear Dark Sky (free, web and iOS)

The original astronomical forecast chart, now available as an app. Covers North America with high resolution. The “Clear Sky Chart” format — a grid of coloured squares for each attribute by hour — is faster to parse than any prose forecast.

Price: Free

Light Pollution Map (free, web/app)

The Bortle scale map for your location. Essential for understanding what sky quality to expect at your observing site and for planning trips to darker sites. The app uses current satellite data for accurate LP assessment.

Price: Free

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The App Setup for Every Astronomer

Minimum useful setup (all free):

• Stellarium Mobile (star charts and identification)
• Clear Outside (weather and seeing forecast)
• Light Pollution Map (site assessment)

Observer with a telescope (€15 one-time):

• SkySafari 7 Pro (full database, telescope control, planning tools)
• Clear Outside (always)

Beginner just starting out (free):

• Star Walk 2 (immediate, approachable)
• Clear Outside (so you only go out on good nights)

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What Apps Cannot Replace

A printed star atlas. At the eyepiece, a phone screen destroys dark adaptation regardless of app quality. Sky Atlas 2000.0 and “Turn Left at Orion” read under a red light do not. Use apps for planning and identification; use printed charts for the session itself.

For the full equipment picture for new observers, see The Complete Beginner’s Guide to Amateur Astronomy 2026.

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