Recurring slope lineae (RSL) on Mars are seasonally abundant along the steep slopes of ancient bedrock in the Valles Marineris canyon region. Here, the RSL are depicted as bright fans that extend down the slopes.
NASA/JPL/University of Arizona
The RSL appear in places such as the Coprates Chasma ridge, within the Valles Marineris canyon, during the northern summer and southern winter (regarding Mars' poles). They begin as dark streaks and fade over time, sometimes leaving bright streaks that are thought to be salt after the moisture evaporates.
NASA/JPL/University of Arizona
Researchers have also noted surprising land slumps in places such as the Melas Chasma and the Valles Marineris canyon. The RSL follow the sun and change with the seasons, but this streak happened to correspond with a topographic slump about 59 feet wide.
NASA/JPL/University of Arizona
Based on a new study of RSL, the white arrows on this image show the largest concentration of the seasonal streaks in the Coprates Montes area of the canyon.
NASA/JPL/University of Arizona
Water still flows across the surface of Mars from time to time, NASA scientists said in 2015. In the photo above, dark, narrow streaks called recurring slope lineae are seen flowing downhill on Mars. Scientists have inferred that they were formed by contemporary flowing water.
NASA/JPL/UNIVERSITY OF ARIZONA/AFP/Getty Images
Recurring slope lineae emanate out of the walls of the Garni crater on Mars.
NASA/JPL/UNIVERSITY OF ARIZONA/AFP/Getty Images
Recurring slope lineae flow down the west-facing slopes of Coprates Chasma, which is in the equatorial region of Mars.
NASA/JPL/UNIVERSITY OF ARIZONA/AFP/Getty Images
"The existence of liquid water, even if it is super salty briny water, gives the possibility that if there's life on Mars, that we have a way to describe how it might survive," said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA.
NASA/JPL/UNIVERSITY OF ARIZONA/AFP/Getty Images
It remains to be seen whether the new discovery improves the odds of life on Mars, but researcher Mary Beth Wilhelm said the results suggest "more habitable conditions on the near surface of Mars than previously thought."