Players battle various aliens on foot and in vehicles as they attempt to uncover the secrets of the eponymous Halo, a ring-shaped structure.

Surrounding the Earth is an enormous man-made ring-shaped structure known as the Orbital Ring System.

In E. coli, dnaB is a hexameric protein of six 471 residue subunits, which form a ring-shaped structure with threefold symmetry.

The protons pass into a ring-shaped structure, a proton accumulator ring, where they spin around at very high speeds and accumulate in "bunches."

The game setting is on or around a giant ring-shaped structure in space.

- It was a single machine, nothing like the extended ring-shaped structures that the Inhibitors had thrown around the gas giant.

These are geological features believed to be almost unique to Venus: huge, ring-shaped structures 100-300 kilometres (60-180 mi) across and rising hundreds of metres above the surface.

PA then oligomerizes with six other PA fragments forming a heptameric ring-shaped structure named a prepore.

In addition, the ring-shaped structure hung within the shell, supporting lights and acoustic clouds, echoes a somewhat similar structure hung within the 1927 shell.

Every square foot was accounted for in the rotating ring-shaped structures she called towns.