Oró became a full professor in University of Houston in 1963 where he founded and directed the department of biochemistry and biophysics. From the 1960s he worked with
NASA on the
Viking missions which explored the planet
Mars. His work was essential in the analysis of samples of Martian soil, questioning early suggestions that life might have been detected. This was achieved during the period 1959–1962 and stands, together with the
Miller-Urey experiment, as one of the fundamental results of
prebiotic chemistry. It opened up a research area eventually leading to the complete synthesis of other components of nucleic acids.
Cometary origin of prebiotic molecules Oró was also the first scientist pointing towards
comets as key carriers of organic molecules to our early
biosphere. This conjecture (formulated in 1961) is broadly accepted today. Although such an idea had been around for a long time, it was only when both space exploration and prebiotic chemistry fully developed that extensive evidence was in place. Comets are rich in carbon and water, bearing along precursor molecules based on carbon chemistry, such as amino acids. In this context, in 1971, Oró and co-workers published a paper revealing the high abundance of amino acids, aliphatic and aromatic hydrocarbons in the
Murchison meteorite and studied the optical activity of the amino acids.
Viking mission Oró also provided a chemical interpretation of a set of remarkable, and to some extent unexpected results reported by the
Viking mission to Mars. The Viking lander performed a series of experiments, including one designed by Oró, involving a small
gas chromatograph and
mass spectrometer. In one of these experiments, where a set of nutrients was mixed with Martian soil samples, a sudden production of carbon dioxide was reported, initially suggesting the presence of Martian microbes, which would have shown some kind of metabolic processing of nutrients. Oró showed that a simpler, abiotic interpretation was more likely to be the correct one: the catalytic chemical oxidation of test nutrients. ==Other activities==