Solar System

The Distant Worlds of Uranus and Neptune

This image shows Uranus with the four largest moons Oberon, Titania, Umbriel and Ariel - and Neptune with its large mooon Triton. The image was taken with my 10" f/5 Serrurier truss Newtonian and is a composite of short exposures for the planet discs and longer exposures for the fainter moons. Miranda, the smallest of Uranus' five larger moons, was very close to Uranus when the image was taken and therefore lost in the glare of the planet itself in the long exposure image used to capture the moons.
The orbits of the moons were added to illustrate the scale and orientation of the two systems as viewed from Earth, with South being towards the top of the image.

Both Uranus and Neptune are so far away from us that their angular diameters are only a few arcseconds, being 3.7" and 2.3" respectively. This makes it extremely difficult to discern any details on them and they nearly always appear as tiny cyan/blue balls except when imaged by large observatories or the Hubble Space Telescope. In fact, the entire orbit of Triton would easily fit behind the disc of Mars when the latter is at opposition. Still, with relatively modest equipment it is possible to get a good glimpse of these fascinating icy worlds.