Answer based on the text
There's no motive given or hinted at in the text or elsewhere, so I'm afraid the only answer I can perceive is 'no' - there is no way to explain Terach's attempt to travel to Canaan based on the text.
Other Thoughts
As pointed out by Abu in the comments to his answer, Canaan was the heart of the 'fertile crescent' linking Eurasia with Africa, and so it's a very natural trading link. For somebody such as Terach who was relocating for any number of reasons, Canaan would be one of the most natural directions to move - it wasn't a known region to their family, but it was still a highly 'significant' area for the ancient world. It's no co-incidence that when Abram moves there he encounters ten or more kings already settled in the region (Genesis 14).