The researchers at the California Institute of Technology say that an ancient delta was found on Mars. Using high-resolution images of a spanning 100 square kilometre area from the Mars Reconnaissance Orbiter (MRO), the researchers discovered the fan-shaped inverted channels that appeared to be emptying into an ancient ocean. The inverted channels appeared as ridges that were made from sediments of coarse material. Slope measurements indicated that the water was spreading out instead of converging. This suggested that these water channels were part of a delta. The researchers also found an abrupt increase in slope downstream suggesting that waters must have emptied into a larger body of water. Since there is no crater nearby, it was suggested that this large body could have been an ocean.