Modern astronomy utilises a range of techniques across the electromagnetic spectrum that allow astronomers to measure the brightness, size and shape of astronomical objects, as well as their structure in many cases. This free course enables you to explore multiwavelength images of the Universe and make your own measurements of stars, nebulae and galaxies using online tools and databases. You will explore the different types of nebulae in the Messier catalogue, considering their sizes and distances using an interactive Scales tool, and use a web tool called Chromoscope to survey the Milky Way in different wavebands.
This free course is an adapted extract from the Open University course S284 Astronomy.

We know how many stars there are in the Milky Way, but how do we know how far they are?

With habitable planets so far apart, is it mathematically feasible to believe that humankind could ever spread across the universe?

Understand the scale of the universe; orbits and gravity; the Solar System; the Sun and other stars; galaxies and the composition of astronomical objects.

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