LeoLabs had said a defunct Russian satellite and a discarded Chinese rocket segment were likely to come within 25m of each other.
It said there were no signs of debris over Antarctica on Friday morning.
Other experts thought Kosmos-2004 and the ChangZheng rocket stage would pass with a far greater separation.
With the objects having a combined mass of more than 2.5 tonnes and relative velocity of 14.66km/s (32,800mph), any collision would have been catastrophic and produced a shower of debris.
And given the altitude of almost 1,000km, the resulting fragments would have stayed around for an extremely long time, posing a threat to operational satellites.