A Mars image shows a strange square formation. Some think it's artificial, but experts suggest natural causes.

The Jurassic Yan ’an Formation in the southwestern margin of Ordos Basin has developed many sets of coal-associated and non-associated mudstone as well as oil shale. Different analytical methods ...

The trip is worthwhile for the views of scenic spots not visible from land and the scores of exotic rock formations along the way. Oshima, the largest of the islands off the Echizen coast ...