Charley -

People will see concave/convex structure more clearly if the lighting is from a direction that seems "normal," and in this case the appearance more closely - as I saw it - matched the description if the image is turned 180 degrees.

The article at the link, with the picture, proclaimed this to be something "really strange."

Especially since satellite imagery became common, but even long before that with moon and planet photos, people have been distributing "weird photos" and proclaiming them to be new discoveries, and news reporters have been taking the bait - for several decades now.

Even low-ranking troops who may have occasion to see tactical image-maps from aerial photographs or satellite imaging have been taught to rotate them before jumping to conclusions; but that training may not have reached the media. (Maybe it's a secret we shouldn't discuss?)

Others may differ, but it seems to me that this one doesn't look at all strange if it's flopped to another orientation.

There's a central "hole" that looks like a typical impact crater, with a shallow depression surrounding the crater. The "lines" look like erosion tracks that could have been caused by "something" sliding down the slope, or by gas/dirt ejected from the impact point at the time of impact.

The shallow crater surrounding the impact "bullet hole" does, obviously, suggest that the Mercurians live in elaborate underground caverns, with the milder slope being the sinkhole that happened when the impacting (meteorite?) punctured the roof of their underground city. As the sinkhole depression is fairly large, this particular impact probably happened to hit their arena where they have the lizard fights, or perhaps a parking lot where they park their magleve turbo transporters when they go shopping. Depressions of this kind probably would be rare, as an underground civilization likely would have quickly learned to avoid large-area roof structures for reasons of safety and convenience in construction, except when there was an important public need for an unusual construction.

The erosion trails might be the result of material they ejected to the surface, rolling into the depression, when they made a replacement excavation or during repairs to the original collapsed area.

We do have a couple of regulars who appear to communicate regularly with extraterrestrials, so maybe we should suggest that they ask about it at their next visit. Even if their regular correspondent(s) aren't actually from there, they may have visited since the event.

John