Laser chemistry, laser photochemistry, and cometary astrochemistry. The main goal of this research is to unravel the key photochemical sinks of important molecules in planetary atmospheres, in our and other solar systems, around stars, and the interstellar medium. This kind of information will allow us to trace the detailed molecular history of our universe. The principle molecules we are studying are N2, CO and CO2. We measure the branching ratio for the production of different states of the product atoms. For example, the N2 molecule can dissociate into N(4S), N(2D) and N(2P) atoms, and the CO molecule can dissociate into C(1S), C(1D), C(3P), O(1S), O(1D), and O(3P) atoms. By determining the branching ratios in all of the available products we can explore excited potential energy surfaces of the respective molecules.