The fact that these footprints were preserved at all is quite astonishing. The volcanic mixture of ashy mud that they were found in came from a truly bizarre volcano named Ol Doinyo Lengai, a member of the enigmatic East African Rift system.
Beneath this mountain – whose name means “Mountain of God” in the local Maasai language – the African continent is splitting apart, and some very curious magmas are rising up to the surface. Ol Doinyo Lengai erupts a black, carbon-rich type that’s often far more fluid than water.
This often means that new flows quickly smother older ones, so any preserved ashen footprints would likely be covered up. However, some of this volcano’s ash was washed further out onto the plains by water flows, where it formed a compactable mud far from the destructive volcanic vent – perfect for preserving footprints.
This isn’t actually the first time human footprints have been found in volcanic material. The Ancient Footprints of Acahualinca, found alongside Nicaragua’s Lake Managua, feature the 2,120-year-old traces of 15 people’s feet. Discovered in 1874, they are just one example of many.
The lunar surface is also made of Hawaiian-like volcanic material and dust, and as there’s pretty much no atmosphere there to erode them, the footprints of the Apollo program astronauts also fall into this rather niche category.
What a wonderful juxtaposition that is, though – human footprints, from the volcanic plains of the African continent to the surface of our Moon in just a few millennia. More than anything, these two distinct time capsules of human evolution are a beautiful illustration of how far we’ve come from such humble beginnings.
One of Buzz Aldrin's footprints on the lunar surface. NASA