A spectrometer capable of detecting ozone absorption features 9 orders of magnitude weaker than the Hartley band has been employed to investigate the molecule's near-infrared absorption spectrum. At this sensitivity a wealth of information on the low-lying electronically excited states often believed to play a role in atmospheric chemistry is available in the form of vibrational and rotational structure. We have analyzed these spectra using a combination of digital filtering and isotope substitution and find evidence for three electronically excited states below 1.5 eV. The lowest of these states is metastable, bound by ~0.1 eV and probably the 3A2 rather than the 3B2 state. Its adiabatic electronic energy 1.24¿0.01 eV, slightly above the dissociation energy of the ground state. Two higher states, at 1.29¿0.03 and 1.48¿0.03 eV, are identified as the 3B2 and the 3B1, respectively. Combined with other recent theoretical and experimental data on the low-lying electronic states of ozone, these results imply that these are, in fact, the lowest three excited states; that is, there are no electronically excited states of ozone lying below the energy of O(3P)+O2(3&Sgr;-,v=0). Some of the implications for atmospheric chemistry are considered. ¿ American Geophysical Union 1995