The few impact craters on the volcanic plain also indicate that the landscape here cannot be very old. The age of the lava flows can be determined quite by counting all of the craters and measuring their various diameters, and comparing this with other areas of Mars. This method of determining the age of geological surfaces can be applied to all bodies in the Solar System that have a solid surface. Scientists therefore assume that parts of this plain were flooded with low viscosity lava in the recent geological past, possibly even less than 100 million years ago. Lava also rose to the surface out of the Cerberus Fossae (and later presumably so did groundwater). This makes the near-Equator region of the Cerberus Fossae one of the youngest geological structures on Mars.