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Touring the Cosmos through Your Home Computer

Although commercial astronomy software such as Starry Night and Slooh make for excellent viewing of the heavens, they come at a price. Fortunately, there is astronomy software that is not only excellent but also free. In this article, we provide a brief overview of ten popular free Desktop Planetarium software programs available for your desktop computer.


Astronomy Software

Significant strides have been made in free Desktop Planetarium software for modern commercial computers. Applications range from the simple to the complex. Many of these astronomy applications can run on several computer platforms

Most amateur astronomers can meet their celestial needs using one or more of these applications. While applications such as Stellarium and Celestia provide a more or less comprehensive portal to the heavens, more specialised programs such as Solar System 3D Simulator provide narrow but focused functionality. 

Regardless of your astronomy viewing needs, the chances are you can find a free application that rivals for-profit alternatives. 

Asynx Planetarium

Asynx Planetarium is a free planetarium and Solar System simulator that provides an ideal format for students and even children. Part of its accessibility to younger users is based on its interface, which is simple and intuitive. 

As with many astronomy applications, Asynx Planetarium can display the night sky from any location on Earth (between the years of 1760 and 9999). Although it covers over 10 000 stars, Asynx Planetarium is less powerful than applications such as Celestia or Stellarium. 

Planets, Messier objects, the 88 constellations and the Moon with phase are all incorporated into this tightly built application. Asynx Planetarium is also suitable for users who want fast animations, which can be obtained from the geocentric and heliocentric views. 

Asynx Planetarium is an excellent choice for users who want a lean and efficient application for learning the basics about our Milky Way, making it suitable for a wide audience. 


Celestia is one of the best free astronomy programs available, which boasts a similar set of features to Stellarium. 

Like all good astronomy software, Celestia allows you to tour the Universe by escaping the limits of viewing from Earth. You can travel through the cosmos to observe a wide collection of galaxies, nebulae and stars. In fact, Celestia features a star catalogue in excess of 100 000 stars. Another great feature of Celestia is the smooth transitions from one frame of view to the next, including a nicely articulated zoom feature.

Another popular feature of Celestia is its ability to point and go to a specific destination. If Celestia’s wide selection of stars, galaxies, planets and smaller terrestrial treasures is not enough, there are numerous add-ons to the application. Celestia Motherload1 is an active and well-maintained website that offers a wide range of additions, including typical Solar System objects, spacecraft and extrasolar objects. 

Deepsky Free

The free version of Deepsky Astronomy Software is known as Deepsky Free. The one benefit of Deepsky Free is its use as an organising and planning tool.

Deepsky Free is especially useful for astronomers who want to create observing plans or star charts. Users should note that while Deepsky Free is a simple tool suitable for astronomical viewing, its functionality is limited by a narrow object database. At approximately 11 000 objects, the Deepsky Free database is limited but focused, providing information about planets, stars and the Messier objects. 


Unlike the other applications on this list, DeskNite offers a live view of the night sky from your computer’s desktop. DeskNite operates as desktop wallpaper that is constantly updated using real-time data, tracking the motion of the Earth. DeskNite relies on a limited catalogue of more than 3000 stars, the planets, Sun and Moon. NGC and Messier objects are also available. 

DeskNite also features a range of viewing perspectives, which includes equidistant, orthographic and stereographic projections. The software also features content from the Sloan Digital Sky Survey, a New Mexico-based programme that focuses on redshift phenomena (objects moving away). 

Digital Universe Atlas

One of the more interesting features of Digital Universe Atlas is the opportunity to view objects in different types of electromagnetic radiation, ranging from radio to infrared radiation, visible light and gamma rays. Digital Universe Atlas is a simple but useful tool for beginner and intermediate astronomers. 

Google Earth

Google Earth is the desktop astronomy application made by the famous search engine company. The application originally made a name for itself by providing seamless views of our planet by stitching together satellite photographs. Astronomers now have a chance to test drive the application for space, thanks to a group of ambitious Google developers. 

Using the feature called “Sky in Google Earth”, you can travel throughout the cosmos on a set of images pulled from the Digitized Sky Survey and the Sloan Digital Sky Survey. The Digitized Sky Survey provides a nearly complete picture of the entire night sky from any point on the globe. 

The Sloan Digital Sky Survey is only partially complete, but provides greater depth and detail. The real benefit of Google Earth is the inclusion of Hubble photographs. Navigating to M31 reveals not only a panoramic portrait of the Andromeda Galaxy, but also a Hubble image. There are also additional details about the image and suggested resources for finding more information on the web. It is this kind of integration between the sky surveys and the Hubble Telescope that make “Sky in Google Earth” a valuable educational tool. 

MHX Astronomy Helper

Probably the most limited application in the group, MHX Astronomy Helper is an ideal tool for young students who want to learn the basic principles of local astronomy. Detailed information is available for major objects in our galaxy, which includes planetary orbits, rotation periods, moons and object composition. Although MHX Astronomy Helper lacks the comprehensiveness of other applications, it is an ideal start for young students and novice astronomers. 

Solar System 3D Simulator

A more advanced tool than MHX Astronomy Helper, Solar System 3D Simulator accomplishes its title claim by providing a dynamic application for viewing the Solar System from a variety of angles. Solar System 3D Simulator offers views of planetary orbits, their moons, and the Sun. 

Information about the chemical composition and physical characteristics of each planet can be displayed. One of the nicer features of Solar System 3D Simulator is the variety of angles that can be used for viewing. Even the speed of the simulator can be altered. The target user of Solar System 3D Simulator includes young students and novice astronomers. 


Stellarium contains many features that make it a fine addition to your astronomy software collection. Stellarium has a built-in catalogue of over 600 000 stars with the potential to add an additional 210 million stars. It also contains illustrations of constellations and a series of asterisms, which are clusters of stars that appear to be together but are actually quite far apart. 

Stellarium offers constellations for eleven different cultures, making it a globally conscious application. It also has a multilingual interface, a pleasant user experience with keyboard control, zoom features, time controls, spherical mirror projection for use with a personal dome, and even a telescope control system. 

Visualisation with Stellarium is also very good and includes extra details such as shooting stars, eclipse simulations, a variety of landscapes, twinkling stars and equatorial and azimuth grids. Advanced users can have fun customising Stellarium by adding deep-sky objects and constellations. 

WorldWide Telescope Microsoft’s

WorldWide Telescope is the last free astronomy application to be examined. Unlike most of the options on this list, the WorldWide Telescope is truly a rich, robust and dynamic tool for exploring the cosmos. One of its nicest features is its ability to view the sky in electromagnetic wavelengths other than visible light, such as X-rays. 

This versatility provides outstanding views of hydrogen clouds, supernovae and high energy fields emanating from nearby stars and star clusters. You can zoom in and out throughout the Universe, view selected planets, and then move forward or backwards in time to see how the night sky looks at another time. 

One of the best features of the WorldWide Telescope is the set of guided tours, each narrated by world-renowned astronomers. You can take tours that cover topics as diverse as how the planets in our Solar System formed and the state of the Universe two billion years in the past. 

The real benefit of Microsoft’s WorldWide Telescope is its ability to be used by a wide range of users. Young students and novice astronomers may begin with objects closer to home, learning about the planets and their properties. More advanced users can move out into the stars without the aid of a guided tour. 

The one downside to the WorldWide Telescope is that it is a large application. Guided tours require specific modules to be downloaded, which can take time on slower connections. But in the end, Microsoft has done an excellent job of delivering an educational and entertaining astronomy application to most computers that use the Windows operating system. 


There is a wide selection of free astronomy software available to an equally wide audience. While several applications provide excellent all-in-one solutions to meet most astronomers’ needs, other tools feature narrow but focused functionality. Young students and novice astronomers may want to begin with MHX Astronomy Helper or Solar System 3D Simulator. The next step up from these starter applications includes DeskNite and Deepsky Free, tools aimed at more advanced users. The best overall experience may be found in Celestia, Stellarium and Microsoft’s WorldWide

Useful Resources

Solar System

Overview of the Solar System  – An article that contains information on what comprises our solar system.

Windows to the Universe – Informative page which looks at the universe and provides helpful data.

Astronomy for Kids – Educational web page for kids that looks at our solar system.

Solar System Information – Useful collection of information, games and more to teach kids about the solar system.


Stars and the Constellations – In this informative page from the University of Wisconsin Observatory you will learn about the stars.

The Story of Stars – Helpful page from the University of Illinois which discusses the stars in the sky.

Facts About the Stars : Useful web page that provides facts and information about stars.

Ask an Astronomer: This web page for kids provides answers to typical questions about astronomy.

Stars for Kids : An educational page for kids that talks about stars, star death and other topics.

Earth and the Planets

Earth Information – Page which provides information on the composition and atmosphere of the Earth.

Earth Facts – A useful page which lists several interesting facts about the Earth.

Earth :This page from NASA gives an interesting overview of the Earth.

Planets for Kids – In this useful page aimed at kids you will find general information about the various planets.

Exploring the Planets – Informative page from the Smithsonian which looks at the planets and other bodies found in outer space.

Space Exploration

Exploration of Space  – Helpful page which provides a look at the world of space and how it is explored.

Exploring Space  – Web page which serves as an information source on the past, present and future of space exploration.

Exploring Space for Kids  – A kid-friendly page with information on how they can begin to explore space.

Kids Information – Useful page for kids with key dates in the history of space exploration.

Space Observation

Hubble Site  – Official website focused on the work on space observation of the Hubble Telescope.

Herschel Space Observatory – Information on the work in observing space of the Cal Tech Observatory.

Space for Kids – Introduction of space observation for kids with facts, games and other activities.

Astronomy – Resources and information about the field of astronomy and space.

Astronomy for Kids – Informative page with fun games, activities and projects for kids to learn about astronomy.

Outer Space Resources

Space Resources Library – a Collection of web pages and articles that provides information on an array of space related topics.

Space for Educators – Useful page that provides resources that can be used by educators for students.

Outer Space Resources – Primary resources to learn about outer space and the solar system.

Solar System Resources – This page from the Lunar and Planetary Institute contains a number of useful resource pages about our solar system.

Activities and Resources – Helpful page from the McDonald Observatory with kid-friendly activities and games about outer space.

Choosing Binoculars

Binocular Basics – Understand the basics of binoculars and why they are an excellent choice to begin with with stargazing. 

Choosing Binoculars for Stargazing – Learn how to choose binoculars for astronomy, and you get some good bets for binoculars that are ideal for looking at the night sky.

How to Choose Binoculars for Astronomy and SkywatchingTo pick the best binoculars for your particular needs, read this handy binocular buyer’s guide.

Choosing Telescopes

How to Choose a Telescope (Video Series) – If you’re looking to buy your first telescope, start by checking out this video series about astronomy telescopes, binoculars, and accessories for beginners.

The Heretic’s Guide to Buying a Telescope– A guide to first-time telescope buyers, with a detailed FAQ, suggested scopes, vendors, books and other resources.

The Purpose of a Telescope – Understand how telescopes work and what is their purpose.

Guidelines for Choosing a Good Telescope – Picking a telescope is a big decision. Find out  some basic rules to keep in mind so you get the best equipment to fit your needs.

Telescope Mounts – Even the most expensive telescope tube isn’t of much use if it is not on a solid mount that points it accurately anywhere in the night sky. 

Accessories for Telescopes – Other than a telescope and mount, you need to have a few accessories such as extra eyepieces, a good finder, a map, and perhaps a light-pollution filter.  


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