Imagine a race with very little knowledge of Earthlings' capacity for violence, but they're aware that anyone could be violent if provoked. They're sending a scout ahead of their main ship. The scout wants to come as close to Earth as possible without be detected. The time frame is not "now", it's "when", this will matter in a moment. Currently I'm thinking they slip behind a NEO and then peel off from it when they're at PCA. The craft with be stealthy to radar but not invisible. So, in the next 100-200 years, are there any large NEOs that would come inside the Moon's orbit but not hit Earth? Better ideas are always welcome, I know my limitations.