Using the information gleaned from a variety of research techniques, it has been possible to construct a complete model of the Milky Way, creating a three-dimensional map some hundred thousand light years across, which forms the basis for the Milky Way sculpture.
The basic structure is a highly flattened disk of stars that is brightest at its centre, and fades with increasing radius, with the Sun lying in its outskirts. In fact, the disk is not quite flat – look closely, and you will see that it has a slight warp away from a single plane.
At the centre of the disk lies a rectangular bar structure. Shock waves form in the bar where gas and dust are concentrated – in the sculpture, you can make out some obscuration by the dust in these shock waves. Seen edge-on, this central structure has the typical “bulge” shape seen at the centres of most disk galaxies.
Emanating from the bar are the beautiful arms that give “spiral galaxies” like the Milky Way their collective name. Most are named after the constellations against which they appear projected.
Away from the disk plane, you will find the surrounding diffuse halo of around a hundred globular star clusters, each of which contains tens to hundreds of thousands of stars.