Although the work he did in lunar and planetary formation which he detailed in the _book The Planets: Their Origin and Development_ is considered highly influential, he is best known for work in chemistry. As Director of War Research for the Atomic Bomb Project at Columbia, 
Although the work he did in lunar and planetary formation which he detailed in the _book The Planets: Their Origin and Development_ is considered highly influential, he is best known for work in chemistry. As Director of War Research for the Atomic Bomb Project at Columbia, he worked on purifying U-235 and earlier had been awarded the 1934 Nobel Prize in Chemistry. For ten points name this Indiana-born scientist best known for isolating heavy water and discovering deuterium.
Although the work he did in lunar and planetary formation which he detailed in the _book The Planets: Their Origin and Development_ is considered highly influential, he is best known for work in chemistry.
Harold {Urey}