The vacuum-UV spectra of supersonic jets of ArKrXe mixtures excited by an electronic beam were investigated. At small concentrations of Kr and Xe admixtures to the Ar jet, intensive continuous spectra of Kr and Xe were observed. Continuous spectra with intensity maxima at 1350 Å and 1540 Å were also recorded and interpreted as the spectra of the heteroatomic molecules ArKr and KrXe.