NASA found a series of “erosion features” on Mars that may be smaller or infant versions of larger erosion features called “spiders.”
These “spiders” are a result of carbon dioxide being released from under ice during the spring season when the ice thaws.
The carbon dioxide builds up and eventually erupts out. As it erupts, it picks up sand and dust, which then falls back onto the ground, appearing as dark streaks on the surface.
These streaks- or channels- can be from tens to hundreds of meters across, and they would often be converging from the center, similar to a spider, hence the term.
“We have seen for the first time these smaller features that survive and extend from year to year, and this is how the larger spiders get started,” says Ganna Portyankina, the lead author from the University of Colorado, Boulder, in a statement.
“These are in sand-dune areas, so we don’t know whether they will keep getting bigger or will disappear under moving sand.”
This process is incredibly slow and takes around 1,000 Martian years (1,900 Earth years). For the first time, scientists saw a number of “infant spiders” growing on mars over a number of years.
“Much of Mars looks like Utah if you stripped away all vegetation, but ‘spiders’ are a uniquely Martian landform,” said co-author Candice Hansen of the Planetary Science Institute in Tucson, Arizona, in a statement.
These spiders oddly only appear in the South polar region of Mars, and not the North. Scientists hypothesize that it might be because there’s less sand in the South and so the channels are less likely to be filled up, and therefore more visible.
“There are dunes where we see these dendritic [branching] troughs in the south, but in this area, there is less sand than around the north pole,” Portyankina said.