We report on a constituent of Earth's radio spectrum that shows remarkable similarities to Jovian ''type III'' or quasiperiodic bursts. These terrestrial bursts lie in the radio LF band, down to the in situ plasma frequency and are made of two spectral components. The lower frequency component exhibits relatively rapid negative frequency drifts, similar to type III solar bursts but on a much shorter time scale. It appears to emanate from a large source region and its characteristics are the same as those of isotropic terrestrial kilometric radiation described by other authors. The higher frequency component does not drift much in frequency, only lasts about 1 to 5 minutes and sometimes extends up to 500 kHz. It appears to emanate from a discrete source. This high frequency component was never reported before because it is often hidden by AKR events. It might be produced by a mechanism which differs from AKR. These LF bursts may belong to a more common class of radio bursts representing a previously unappreciated segment of Earth's radio spectrum. ¿ American Geophysical Union 1996