Practical tools for stargazers

Astronomy Tools

Plan an observing session, compare telescope and eyepiece combinations, and make better use of the clear South African night sky.

Available now

These tools are free to use and do not require an account.

Calculate focal length, focal ratio, magnification, exit pupil, true field of view and useful power limits.

Compare cloud, humidity, dew risk, wind and rain forecasts to find the best observing window over the next seven nights.

Plan around Moon phase, moonrise and moonset, twilight and the best moonless astronomical-darkness windows.

Calculate image scale, sensor framing, effective focal length and sampling, with previews for popular celestial targets.

Estimate dew point, optical-surface cooling margin and sensible dew-heater guidance for an observing or imaging session.

The tools below will be added to this page as they are completed.

Coming soon

Find suitable planets, clusters, nebulae and galaxies for your location and equipment.

Coming soon

Choose a suitable telescope type based on your interests, location and portability needs.