The Naked-Eye Sky

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Our eyes can make out many different objects in the night sky, including bodies in the Solar System, stars in our galaxy, and even neighboring galaxies.

What do our eyes reveal?

On a clear evening, the night sky appears as a sparkling dome of stars stretching from horizon to horizon. Away from the lights of towns and cities, a deeper level of this majestic nightscape is revealed, with the myriad stars of our galaxy, the Milky Way, creating a glowing, misty band across the sky. There are transient characters too in this nightly show: the fleeting streak of a shooting star, or the occasional delicate shimmer of an aurora. Then there are the planets, our companions in space. They slowly wander across the background firmament as they orbit the Sun. The Moon is frequently present in the night sky. Its bright light can often wash out the fainter stars, but it is itself a fascinating object to observe, covered in smooth, dark "seas" as well as cratered and mountainous regions.

The constellations

Over time, humans have invented narratives to explain the patterns seen in the stars. These patterns are said to represent characters or objects from a mixture of ancient and relatively modern mythologies. Today the night sky is divided up by astronomers into 88 official areas, known as the constellations, each with its own demarcated boundaries. Stars located in the same constellation are not necessarily near each other - these groupings are just a convenient way to identify a particular area of sky.

Our galactic neighbours

Most of the objects that can be seen unaided in the night sky are stars that lie within our own galaxy - the Milky Way - but we are not alone in our corner of the Universe. The Milky Way and over 30 nearby galaxies make up a galaxy cluster known as the Local Group. Among this group are several galaxies that, from a dark-sky site, can be readily picked out with the naked eye, appearing as small, misty patches against the background stars. Two of the most prominent naked-eye objects in the southern hemisphere are two galaxies in the Local Group close to the Milky Way: the Small Magellanic Cloud and the Large Magellanic Cloud.