NASA’s Perseverance is exploring the famous delta of Jezero Crater but many images that have come out of the last few weeks are not of pristine geological structures but of the rubbish that the Entry, Descent, and Landing hardware (EDL) left behind when delivering the rover to Mars. A peculiar ball of string (or spaghetti) spotted by Perseverence a couple of weeks ago in Hogwallow Flats is among them, and astronomers now believe they know what it is.

The string is a piece of the Dacron netting material, which was used in the thermal blankets of the EDL. A few weeks previously, Perseverance spotted some of it looking like strange shed snake skin. The knotted material is much more degraded.

“The hardware teams suspect that this is another piece of Dacron netting, based on the observed 2x2 mm2 grid mesh pattern. They noted that this particular piece of netting appears to have undergone significant unraveling/shredding, suggesting that it was subjected to strong forces,” Justin Maki, Imaging Scientist and Mastcam-Z Deputy Principal Investigator at NASA's Jet Propulsion Laboratory, wrote in a blog post.

Finding debris from the EDL stage is not unusual for rovers but the amount Perseverance has come across and how far away they are seems a bit unexpected. The EDL was purposely crash-landed a couple of kilometers (just over a mile) away from the science investigation site but the rover continues to spot the remains of the collision between the skycrane and the Martian ground. 

The team believes it's possible some of these fragments were thrown up in the air by the crash, but most of them seem to have been carried about by the wind over the course of the year.

“Hogwallow Flats appears to be a natural collecting point for windblown EDL debris. Perseverance team members are reviewing images of the debris, checking to see if the material may pose as a potential contamination source for the sample tubes from this area," Maki explained. 

"Although there are no immediate concerns identified by the teams at this time, the teams are documenting the EDL debris materials as they are identified.”

The team will continue to study this debris both to make sure they don’t affect the mission, but also to improve future missions to this and other worlds.