At the beginning of Best of Both Worlds, an away team beams down to the New Providence colony and is surprised to find that it is not there. The colony has been removed from the surface in a manner similar to what happened to the Federation and Romulan outposts in The Neutral Zone as well as the cities in System J25 in Q Who.
In their earliest encounters with the Borg, the Enterprise was able to see that the outposts and cities were not there from orbit with no mention made of away teams.
So why did they have to beam down to New Providence to see that the colony was gone? Couldn't they have seen it (or not seen it) on sensors?
Note: I'm only asking about the away team at the beginning of the episode. I understand why the subsequent away team beamed down to investigate whether or not it was actually the Borg.