How are these things related?

Question

The following list has 5 groups of five that are related to one another. Sort them into their 5 groups of five based on their similarities:

Parallax
Ramapithecus
Robot
Glomar Challenger
White Dwarf
Pocketronic
Paul Langerhans
Mammography
P waves
Sonar
Abell Clusters
Buckminister Fuller
Nereid
Palenque
Pre-Cambrian Shield
Dialysis
Nebula
Angioplasty
Gottlieb Daimler
Papyrus
Daniel Barringer
Pancrease
Meave Leakey
Mineral
Minoan

Answer 1

The five categories would seem to be something along the lines of
Astronomy, archeology, medicine, geology, and physics. Most of these terms seem to fit readily into one of these categories, and a bit of research on the unfamiliar terms would show which ones they fit into as well.
If that doesn't work, modify the categories a bit.