Huge Water Reserves Found All Over Mars
Published 15 Jan 2018, 13:48 GMT, Updated 15 Jan 2018, 15:58 GMT
Gullies fringe the edge of southern Mars's Hale crater. On Earth, these structures usually form through the action of liquid water.
Photograph by NASA, JPL Cal-tech
In 2004, the NASA Mars rover Opportunity found sphere-like grains nicknamed "blueberries." These grains of hematite probably formed in wet sediments.
Photograph by NASA, JPL, Cornell, Usgs
Alluvial fans are gently sloping wedges of sediments laid down by flowing water. Some of the best-preserved alluvial fans on Mars are in Saheki Crater, seen here.
Photograph by NASA, JPL Cal-tech, Univ. of Arizona
In 2015, scientists found dark streaks flowing down some Martian hillsides. Initially, salty liquid water was considered the culprit, but recent studies suggest that the streaks are in fact dry cascades of dust.
Photograph by NASA, JPL Cal-tech, Univ. of Arizona
In October 2017, scientists unveiled evidence that 3.7 billion years ago, Mars's Eridania basin was a vast ocean with hydrothermal vents—potentially offering conditions friendly to ancient life.
Photograph by NASA, JPL Cal-tech
Gullies snake down the northwest rim of Hale crater. It's unclear how the gullies formed, but some resemble features on Earth that are carved by flowing water.
Photograph by NASA, JPL Cal-tech, Univ. Arizona
In 2012, NASA's Curiosity rover found the remains of a stream that once ran vigorously across Mars's surface. These rocks, which contain ancient streambed gravels, were the first of their kind found on Mars.
Photograph by NASA, JPL Cal-tech
The pinkish, scaly texture is Martian bedrock that water altered long ago, forming clay-bearing rocks. It's still unclear how exactly the rock and water interacted.
Photograph by NASA, JPL Cal-tech