Polygonal ridges on the surface of Mars as seen from the Mars Reconnaissance Orbiter.


Planet Four: Ridges is back! Researchers need your help to find a different kind of ridge feature that is found in the northern midlatitudes of Mars just south of the equator. These ridges often look like broken spider webs or tattered lace. Almost half a million classifications are required to finish this phase of the project, so get stuck in and explore the Red Planet today at ridges.planetfour.org.