One of the things that has come from the Pioneer 10 and 11 and Ulysses satelllites is anomalous gravity behavior on the (approximate) scale of the dark matter effect within our solar system:
Either dark matter exists in our solar system or some other mechanism is responsible for the effect that is not part of the standard model of gravity. And if dark matter exists this close, we should be able to find it.
we are limited in our ability to understand by our ability to understand