A simple coronagraph was modified for use abroad Skylab to photograph the earth's horizon just before spacecraft twilight as a device to monitor the aerosol component of the earth's atmosphere above the tropopause. This coronagraph technique allows one to investigate these high-altitude aerosols from a uniquely favorable position in the particles forward scattering cone. The method is thus 10--100 times more sensitive than daylight horizon scans made when the sun is well above the horizon. An 8-month observing program using seven narrow band filters was planned. Owing to a multitude of spacecraft and equipment mishaps, including the loss of access to the solar airlock, only one reducible photograph was obtained on a late November (1973) extravehicular activity. This particular picture was taken through a 250-¿ bandwidth filter centered on 3600 ¿. Since aerosol layering is detected as an enhancement of radiation above the Rayleigh-background, this wavelength region, although it is free from the spectral influence of ozone, has a relatively high background level compared to longer wavelengths. Even at this high background level the coronagraph picture provides evidence which is consistent with an aerosol layer peaking at 48¿1 km. The region photographed was centered on 26.5¿E longitude, 63.0¿S latitude. This first observation at high southern latitudes suggests the global nature of the layer.