Best Astronomy Software for PC, Mac & Linux

Astronomy software can turn a desktop or laptop computer into anything from a detailed planetarium to an observing planner, telescope controller or astronomical image-processing workstation. Some programs recreate the night sky from almost anywhere on Earth, while others let you study the Moon in detail, travel through the universe in three dimensions or work with real astronomical data.

The seven programs below have been chosen because they each do something genuinely useful and distinctive. Some are ideal for beginners who simply want to learn their way around the night sky, while others are designed for telescope users, astrophotographers or anyone wanting to investigate astronomy in greater depth. Better still, all seven can be downloaded and used for free.

If you’re looking for something to carry outside instead, see our guide to the best free stargazing apps for iPhone and Android. For more advanced mobile options, see our best premium stargazing apps.

Best Astronomy Software at a Glance

Stellarium — Best All-Round Astronomy Software

Stellarium is the best place to start if you want one program for exploring and learning the night sky. It turns your computer into a realistic planetarium, showing the stars, planets, constellations and deep-sky objects visible from your location at any chosen date and time.

The software is especially useful for planning a night outside. You can search for an object, see where and when it will appear, change the field of view to approximate binoculars or a telescope, and switch to a red night mode when using the program alongside your observing equipment. More advanced users can also connect Stellarium to compatible telescopes.

Despite its depth, Stellarium remains approachable for beginners. The standard catalogs contain more than 600,000 stars and 80,000 deep-sky objects, with additional catalogs available for users who need considerably more. Unlike older desktop software that can feel dated or highly technical, its realistic representation of the sky is also a large part of its appeal.

Stellarium is open source and available for all three major desktop operating systems. If you only install one astronomy program from this list, this is the natural place to start.

Available for: Windows, macOS and Linux
Cost: Free

KStars — Best for Observation Planning and Telescope Control

KStars goes considerably further than a basic planetarium. You can use it to navigate the night sky and find astronomical objects, but its real strength is helping more experienced observers plan sessions and work with telescopes and other astronomy equipment.

Its observing tools include an observation planner, altitude charts and information about which objects are visible from your location. This makes it useful when you’re deciding what to observe during a particular night rather than simply browsing a simulated sky.

KStars also includes Ekos, an astrophotography and observatory-control system that can work with compatible mounts, cameras, focusers and other equipment through the INDI framework. It supports functions including telescope control, focusing, guiding and image capture, giving the software considerably more scope as your observing setup becomes more advanced.

That depth means KStars has a steeper learning curve than Stellarium, and beginners who simply want to learn the constellations probably won’t need everything it offers. But for observers moving toward telescope control or computer-assisted imaging, it provides a remarkable collection of tools in a single package.

Available for: Windows, macOS and Linux
Cost: Free

Cartes du Ciel (SkyChart) — Best for Detailed Star Charts

Cartes du Ciel, also known as SkyChart, takes a more traditional approach to astronomy software. Rather than concentrating on a highly realistic view of the night sky, it is designed to create detailed and customizable star charts for planning observations.

You can choose which stars, deep-sky objects and other information appear on a chart, adjust its scale and orientation, and build a view suited to the part of the sky you intend to observe. Additional astronomical catalogs can also be installed, including extremely large stellar datasets for users who want to work at much greater depth.

That makes SkyChart particularly useful when a planetarium display starts to feel too general. An observer can prepare a chart for a particular target or region of sky and include the level of detail needed to identify objects through a telescope.

The interface is more functional than polished, and the current stable release is relatively old, although development builds and newer astronomical catalogs remain available. Its strength is ultimately precision rather than presentation: SkyChart is for observers who want serious, highly configurable star charts.

Available for: Windows, macOS and Linux
Cost: Free

Virtual Moon Atlas — Best for Exploring and Observing the Moon

Virtual Moon Atlas is a specialist program devoted entirely to our nearest celestial neighbor. Instead of showing the whole night sky, it provides a detailed interactive map of the lunar surface that can be used to identify craters, mountain ranges, seas and thousands of other features.

One of its most useful observing features is the ability to display the Moon for a particular date and time. This lets you see how the changing angle of sunlight affects the appearance of lunar features and identify areas close to the terminator, where long shadows often make craters and mountains especially easy to see through a telescope.

Clicking a feature brings up information about it, while additional image libraries and higher-resolution textures can be installed for much deeper study. You can also adjust the display to match different telescope orientations, making the atlas useful alongside an actual lunar observing session.

Its specialist focus is precisely why it belongs here, providing far more lunar detail than a general-purpose planetarium.

Available for: Windows and Linux
Cost: Free

Celestia — Best for Exploring the Universe in 3D

Celestia takes a very different approach from traditional planetarium software. Instead of keeping your viewpoint on Earth, it lets you travel freely through a three-dimensional model of the universe, moving between planets, moons, stars and other celestial objects.

You can leave Earth, fly across the Solar System, view planets and their moons from different perspectives, or travel outward to nearby stars and more distant objects. Time controls also let you watch objects move along their orbits and see how astronomical systems change from viewpoints that would be impossible in real life.

This makes Celestia a useful way to visualize scale and spatial relationships. Reading that Saturn has dozens of moons or that nearby stars lie several light-years away is one thing; moving around these systems in three dimensions makes those relationships much easier to visualize.

Celestia isn’t really a replacement for Stellarium when you’re planning an evening under the stars. Its strength is exploration rather than practical observing. If you’ve ever wanted to leave Earth’s surface and roam around the universe from your computer, however, few astronomy programs offer quite the same experience.

Available for: Windows, macOS and Linux
Cost: Free

Aladin Desktop — Best for Exploring Real Astronomical Data

Aladin Desktop takes us beyond simulated skies and into the real images and data used by astronomers. Developed by the Strasbourg Astronomical Data Center (CDS), it lets you examine astronomical surveys, images and catalogs covering objects across the sky.

Search for a galaxy, nebula, star or other object and you can view observations made at different wavelengths, overlay catalog data and compare information from major astronomical surveys. Aladin also connects naturally with CDS resources such as SIMBAD and VizieR, opening the door to an enormous amount of professional astronomical information.

That makes it particularly interesting if you’ve ever wondered what lies behind the polished astronomy images and simplified facts found online. You can investigate an object using actual observational data, compare how it appears in different surveys and see which stars, galaxies and other sources have been cataloged in the surrounding field.

Aladin is more technical than the programs most beginners will need. This is where it earns its place: it provides a bridge between looking at the sky and investigating the astronomical data behind it.

Available for: Windows, macOS and Linux
Cost: Free

Siril — Best for Astrophotography Processing

Siril is designed for a completely different stage of the astronomy journey: turning images captured through a camera and telescope into finished astrophotographs. It provides a comprehensive set of tools for processing images of galaxies, nebulae, star clusters and other deep-sky objects.

A typical astrophotography session produces many separate exposures rather than a single finished photograph. Siril can calibrate, align and stack those images to improve the signal and reduce noise before you move on to processing. Its tools also include background extraction, color calibration, image stretching, deconvolution and astrometric functions.

Beginners can use scripts to automate much of the standard preprocessing workflow, while more experienced astrophotographers can take much greater control over individual processing stages. That gives Siril room to grow with the user rather than being useful only at one level of experience.

Siril is considerably more specialized than the observing programs above, but it rounds out this list nicely. Once you’ve progressed from finding objects to observing and photographing them, it provides the tools needed to turn those raw exposures into an image you can actually share.

Available for: Windows, macOS and Linux
Cost: Free

Which Astronomy Software Should You Choose?

If you only want one program for learning your way around the night sky, Stellarium is the natural place to start. From there, the right software depends on what you want to do — whether that’s controlling a telescope, studying the Moon, working with astronomical data or processing your own images.

Desktop astronomy software and smartphone apps ultimately complement each other rather than compete. A computer gives you more space and power for planning, investigating and processing, while a phone is often more convenient when you’re actually standing outside beneath the stars.