Skin ulcers are crater-like, open wounds on the skin. Ulcers are roughly circular with a raw center. They often have thick and raised outer borders and may leak clear fluid, blood, or pus. Skin ulcers ...

Why it's incredible: The lake is the only place on Earth that's similar to Jezero crater on Mars. Lake Salda is a body of water in Turkey that bears a strong resemblance to Mars' Jezero crater.

Shatter cones formed by the impact in the Pilbara. (Image: Tim Johnson) We have discovered the oldest meteorite impact crater on Earth, in the very heart of the Pilbara region of Western Australia.

The 15-foot-wide crater opened up in the median of the busy road, forcing authorities to close the westbound lanes.

Rescue workers in Seoul spent 18 hours trying to recover the man after the huge 65.62ft-deep crater suddenly appeared. The road suddenly caved in at around 6.30pm local time on Monday. The man had ...