This chemistry wordoku looks at how space spores brought life on Earth!

Solve this wordoku in the same way as a sudoku with letters instead of numbers (each of the nine letters in each row, column and nine-square cell). Once solved, one of the overall diagonals can be rearranged to give the jumbled surname of a Nobel prize-winning chemist who first expounded a fundamental hypothesis in the German journal Die Umschau.

This week’s letters are: A E H I N P R S U