Janowski was a member of the Starnes Exploration Party, and father of Mary Janowski.
He along with the other adult members of the expedition committed suicide by cyalodin while under the influence of Gorgan. (TOS: "And the Children Shall Lead")
He was played by James Drake.
Mary's surname was deduced from the visual association made between her and the "Janowski" headstone. The fact that this man was her father can be determined by the interactions between the children and their parents, and the association between the two, in the video footage viewed on the bridge.