FIG. 2.

Wavelength-dependent albedos for a variety of surfaces. The shaded regions correspond to O₂ monomer and dimer bands. For any absorption band, as long as the albedo does not vary widely within the band's wavelength range, it should be possible to measure an accurate equivalent width for each feature. The maximum variation within a band is no more than ∼20%. Therefore, we do not consider surface albedo variations important for this work. (Color graphics available online at www.liebertonline.com/ast)