3 Comments »Posted on Wednesday 4 March 2009 at 9:31 pm by Jacob Aron
In Just A Review, Space & Astronomy

It may have slipped by you with all the Darwinmania that’s about, but 2009 is also the International Year of Astronomy. With that in mind, I thought I’d take a look at some of the software out there that can allow you to explore the universe to your heart’s content.

Now, there really is no substitute for the real thing; a night’s sky crammed with stars truly is a wondrous sight to behold, but unfortunately I’ve only ever experienced it on rare holidays to the middle of nowhere. If you live in a city like London, a combination of cloud cover and light pollution mean it’s hard to even see the brightest stars on most days.

Enter Stellarium and Celestia, two free open source simulations of space with two slightly different approaches.


Stellarium is a planetarium for your computer. The slick interface allows you to select any location on Earth from which to view the stars, as well as a whole host of other options.

Stellarium after the initial load (click for bigger)
Stellarium after the initial load (click for bigger)

You can move about the sky at will, zooming in on objects of interest at any point in time – controllable at will, backwards and forwards. As you can see from the initial image, I couldn’t see much to begin with – it was day time! After a bit of fiddling, such as removing the atmosphere and adding in some labelling, I was able to come up with this:

That's more like it (click for bigger)
That's more like it (click for bigger)

There are a whole host of other options however, such as some rather nice constellation art – and not just Western constellations. Other cultures have their own starlore, and Stellarium can accommodate many other celestial join-the-dots. You can even change the ground view from the default field to a few other options – including the view from a Mars rover.

Stellarium is a very nice piece of software, and the ease of use is especially impressive considering it is currently at the very early version 0.10.0! My only criticism is that it’s very Earth-centric – exploring the galaxy (or beyond) is a little tricky. To be fair, that’s because Stellarium is designed to be used from the Earth’s point of view, unlike our next piece of software.


Would you like the entire universe on your desktop? That’s what Celestia offers – well, not quite. Memory limitations mean the “universe” is cut short at about 16,000 light-years from the Sun, but a fully 3D representation of even this relativity small section of space is pretty impressive.

Celestia's default view (click for bigger)
Celestia's default view (click for bigger)

You’re not just shackled to Earth, either. A few keyboard commands will send you whizzing off in any direction, travelling at anywhere from walking speed to much faster than light. The entire solar system is modelled in 3D, as is much of the rest of the galaxy.

As with Stellarium, Celestia allows you to manipulate time to your whims at a number of speeds – although the date will freeze at the year 5,874,774! Also included are a guided tour of the solar system, and an eclipse finder, demonstrated below.

An eclipse due to take place later this year, simulated in Celestia (click for bigger)
An eclipse due to take place later this year, simulated in Celestia (click for bigger)

Celestia is much less use friendly than Stellarium, however. Not much can be done with the mouse, so I was forced to leave the list of keyboard commands on screen (as you can see above) which rather spoils the view. Having said that, once you get to grips with it Celestia is the more powerful of the two programs.

In addition to natural phenomena, Celestia can also display a number of man-made objects up in the sky. I enjoyed watching the International Space Station floating serenely over the Earth’s surface – it’s seriously tiny. If that’s not enough, you can add to the default object set with a series of add-ons – even fictional places from Star Wars and Star Trek!


It’s hard to choose between these two great pieces of software, as they both have their strengths and weaknesses. Ultimately, it’s a toss up between depth and dedication. If you just want a quick look at some stars, plum for Stellarium with its easy interface. On the other hand, for a galaxy and more at your fingertips, Celestia is your answer, provided you take the time to learn to use it.

I will add one caveat: as I said before, Stellarium is still fairly early on in development. Hopefully as the software improves more features will be added, and if so it might just pull ahead. Even so, both programs are a great way to admire the stars.

  1. 3 Comments

  2. Nice review, I too found Stellarium to be the perfect Earth centric and user friendly universe viewer. But for the real virtual universe buff, you cannot go past Celestia for its completeness and sophistication.

    By Hiltz on Saturday 17 April, 2010 at 1:01 pm

  3. Why choose between pieces of Software?? Why not just have BOTH. Stellarium is for observing the sky from earth, Celestia is for travelling around the universe. Think you’ll find those two concepts are COMPLETELY DIFFERENT, and therefore making them a choice between the two completely preposterous!

    By Mezmrz on Wednesday 18 August, 2010 at 2:29 pm

  4. This post actually gets a fair number of hits from people looking for a comparison between the two, so I don’t think it’s unreasonable. And I do make the point that Stellarium is designed to view the stars from Earth, whereas Celestia is a desktop “universe”.

    By Jacob Aron on Wednesday 18 August, 2010 at 2:35 pm

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