means To probe is to investigate or explore something carefully, often by physically reaching into or sensing through it; as a noun, a probe is the slender instrument or mission sent to do exactly that.

from From Latin 'probare,' to test or prove (also the root of 'prove' and 'probable'), via the medieval Latin 'proba,' a test. It entered English first as a surgeon's slim tool for searching wounds — a way of asking the body a question — before the word reached outward to spacecraft, sensors, and any inquiry that pushes where the eye can't go.