* Astronomy

Lemon tart craters on Mercury are solar system first

Spotted by a NASA probe, the craters are unlike anything seen on other rocky worlds, adding to the diversity of geologic processes known to occur in the solar system.
The pies were found in Mercury's northern highlands, which were flooded repeatedly with volcanic eruptions early in the planet's history. These floods buried underlying impact craters, but as the lava cooled, the crater rims became visible as the material above them wrinkled and split, forming the edges of the pie crust.
Read more