The North America Nebula is huge, covering an apparent area of sky more than four times the size of the full Moon. However, its surface brightness is low, making it a very faint fuzzy patch to the naked eye in dark conditions. Through binoculars it is possible to start to make out the shape of the nebula and its uncanny resemblance to the continent of North America. Once filters are introduced to start to limit the wavelengths observed, great detail starts to emerge in the different regions of the nebula. In this image the areas of hydrogen alpha are shown in red and the lighter blue colours are ionised oxygen.

The North America Nebula and its neighbour, the Pelican Nebula, are in fact parts of the same interstellar cloud of ionized hydrogen. Between the Earth and the nebula complex lies a band of interstellar dust that absorbs the light of the stars and nebulae behind it, and is therefore responsible for the shape as we see it. The nebula is lit by a star behind the dust, emitting ultraviolet light that energises the hydrogen in the cloud, causing it to emit a reddish light.

This image shows the central portion of the nebula, better known as ‘The Gulf Of Mexico’, with a darker area in Florida’s location. The Cygnus Wall is a term for the ‘Mexico and Central America’ part of the North America Nebula. This region exhibits the most concentrated star formations in the nebula.

The nebula was discovered by William Herschel on October 24th 1786 from his observatory in Slough. It is hard to imagine anybody seeing much, let alone discovering anything in the night sky from Slough these days as light pollution has become such a part of the modern world.