Does Astronomers have an apostrophes

Use an apostrophe after the "s" at the end of a plural noun to show possession. It is not necessary to add another "s" to the end of a possessive plural noun. If a plural noun doesn't end in "s," add an apostrophe + "s" to create the possessive form.

c) by giving an example of how mary beth tinker did, in fact, disrupt her mathematics class

explanation:

petitioner john f. tinker, 15 years of age, and solicitor christopher eckhardt, 16 years of age, went to secondary schools in des moines, iowa.