Why not make shift the exploration focus from I wonder if there is anything here to I wonder what that is.

Have the whole map revealed to the player but mark the anomalies using either a symbol based system or a color coding. So the player arrives at the planet looks at the scans and thinks to themselves hmm should I investigate that large magnetic disturbance emanating from the equator or the large structure buried under the polar ice caps? I'm also getting some unusual bio scan readings from a section of jungle in the southern hemisphere I wonder which I should investigate first.

You could and an element of character progression to it by having different sensor modules that player has to purchase in order to detect different types of anomalies. So without a bio scanner you can’t detect life forms. In this way you give the explorer players a way of judging how far they have come and goals to aim for. Such as: Okay I have the bio scanner, magno scanner, and mass spectrometer, so do I buy the thermal scanner or save up for the density differential detector.