February 7, 2016 Comments (0) Views: 2784 Astronomy, Education, Miscellaneous, Resources, Space

Start Doing Astronomy with Stellarium

One of the biggest issues with map-making that persists to this day is translating spherical geometry to a euclidean plane; that is, it’s impossible to accurately portray the surface of a ball on a flat surface. Seriously; just look at the difference between proportions of Greenland and Africa on the Mercator projection – one of the more widely used world maps – and their actual relative sizes. Astronomy has the same problems.

A comparison of Greenland (blue) and Africa (red) on the distorted Mercator Projection, and their accurate relative sizes.

A comparison of Greenland (blue) and Africa (red) on the distorted Mercator Projection, and their accurate relative sizes. Click image for source.

With geographical maps, it’s easy to ignore or surpass the problems of geometry. Globes get around these issues, but they aren’t a very practical solution in terms of portability. At least not until smartphones came along, with the potential for digital globes like Google Earth (Google Maps uses the mercator projection). We also do not use maps on a very large scale; any navigating that we do is usually pretty local.

But when dealing with astronomy, we can’t get around the problems so easily. And beginner level astronomers do deal with the night sky on a large scale. You could buy a star globe, but the night sky is more easily viewed as the inside surface of a hollowed-out sphere. The stars are far enough away that they all blend into a backdrop. In fact, it was believed for some time prior to modern astronomy that the stars were part of a backdrop to the universe – the edge of all things. (This was associated with the earth-centered model of the solar system.) So, though putting the stars on a globe will keep the proportions correct, the translation can be a little getting used to.

You could get an old fashioned map of the sky, but you run into the same geometrical issues. Below is a two-dimensional view of the whole sky as viewed from Earth. The white band that stretches across the image is the milky-way galaxy, where we live. Far less recognizable than the halo shape you would see while stargazing. Also notice how the stars stretch towards the edges of the image. It just doesn’t translate well.

A Mercator-style projection of the night sky.

A Mercator-style projection of the night sky. Click image for source.

When I started doing astronomy, I played around with of different maps, handbooks, and applications, and nothing really worked quite as well as Stellarium. It really is one of the best tools out there for beginners and hobbyists, in my opinion.

It’s an absolutely free program that you can download onto your computer, and acts much like a digital planetarium. It offers real-time views of the sky from any location on Earth. It even has time travel abilities, so you can see celestial phenomena that will happen in the future (like the 2017 US eclipse), or that happened in the past.


Viewing the Great Orion Nebula with Stellarium.

You can find the coordinates of almost any stellar body that you’d like to see, and can often zoom-in on the object of interest to see more detail. You can change the settings to show constellations of various cultures, visualize the orbits of planets, and find the locations of some of the smallest bodies in our solar system. You can even control the levels of light pollution to have reasonable expectations of your viewing conditions. Oh, and it has a night mode so you can comfortably use it without obstructing your stargazing abilities from the bright light of a laptop screen.

This app was an enormous help for me when I started doing astronomy; finding objects was so much easier, I was able to learn much faster, and the applications extend well beyond immediate stargazing. Even if you don’t own a telescope, or spend much time looking upwards, it’s a beautiful and simple way to learn more about the stars that are always hanging above you.

You can download it – for free – here (and you should).

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