The reaction C( 3 P J )+O 2 (X 3 Σ g - )->CO(X 1 Σ + )+O( 1 D 2 ) has been studied with pulsed, crossed, supersonic molecular beams in the range of relative translational energies E T =0.41-12.0kJ/mol. C( 3 P J ) reactant and O( 1 D 2 ) product have been detected by laser-induced fluorescence in the vacuum ultra-violet. Relative integral cross-sections have been found proportional to (E T ) - 1 . 0 0 + /- 0 . 0 3 below E T =6 kJ/mol, indicating that the reaction proceeds without any threshold energy.