H2 Spectroscopy in the Photodissociation Region of M17 Northern Bar

We present results of long slit spectroscopy, from 2.0 to 2.5 microns, of the photodissociation region in the northern bar of M17. The observations give us an insight into the physical conditions in the region and provide evidence which suggests that the ortho to para ratio of molecular hydrogen does not equal 3. We briefly discuss the astrophysical relevance of this.