Complex sentence: On 7 February 1991 Salyut 7 had uncontrolled reentry with Cosmos 1686 reentering over Argentina, scattering much of its debris over the town of Capitan Bermudez.
Split into simpler sentences: On 7 February 1991 Salyut 7 had uncontrolled reentry with Cosmos 1686. Reentering over Argentina, scattering much of its debris over the town of Capitan Bermudez.