Inland blue holes, however, are unlike any other environment ... Many astrobiologists believe such conditions may exist in pockets of liquid water deep beneath the surface of Mars or in a sea ...

which also serves to aerate the water. Oxygen levels wane and fish vacate the shallows. A quick tip for understanding seasonal panfish behavior: Crappies and bluegills suspend in deep holes in ...

Taam Ja' Blue Hole can be found in Mexico's Chetumal Bay. It's an underwater sinkhole, known as a "blue hole" – and is believed to be the deepest of its kind. The giant hole is 498 feet wide and ...

Enormous crater appeared suddenly in part of Russia, Yamal, where name translates as 'the end of the world' Some thought the rare and unusual structure, which was up to 300ft (70 metres ...