You will be given a definition of a task first, then some input of the task.
In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Those in the halo contain many more stars and are much older than the less dense open clusters in the disk .
Output:
Globular clusters are found in the halo of a galaxy and contain considerably more stars , and are much older , than the less dense , open clusters which are found in the disk of a galaxy .