Abstract
Recent observations have revealed an unexpectedly high binary fraction among the Edgeworth-Kuiper-belt objects (EKBOs). The discovered binaries are characteristic so that theories of binary asteroid formation ever known cannot explain the formation of EKBO binaries. Here we show a mechanism which naturally produces the EKBO-type binaries. Our theory implies that EKBOs were formed through gravitational instabilities of the protoplanetary dust layer.
