![\"Electron](\"https:\/\/cdn.sci.news\/images\/enlarge13\/image_14409e-Bennu-Gum.jpg\")
<\/a><\/p>\nElectron microscopy of a particle from the sample from Bennu. Image credit: Sandford et al., doi: 10.1038\/s41550-025-02694-5.<\/p>\n
Bennu\u2019s ancestral asteroid formed from materials in the Solar Nebula \u2014 the rotating cloud of gas and dust that gave rise to the Solar System \u2014 and contained a variety of minerals and ices.<\/p>\n
As the asteroid began to warm, due to natural radiation, a compound called carbamate formed through a process involving ammonia and carbon dioxide.<\/p>\n
Carbamate is water soluble, but it survived long enough to polymerize, reacting with itself and other molecules to form larger and more complex chains impervious to water.<\/p>\n
This suggests that it formed before the parent body warmed enough to become a watery environment.<\/p>\n
\u201cWith this strange substance, we\u2019re looking at, quite possibly, one of the earliest alterations of materials that occurred in this rock,\u201d said Dr. Scott Sandford, a researcher at NASA\u2019s Ames Research Center.<\/p>\n
\u201cOn this primitive asteroid that formed in the early days of the Solar System, we\u2019re looking at events near the beginning of the beginning.\u201d<\/p>\n
In the study, the authors examined the characteristics of Bennu\u2019s gum-like material.<\/p>\n
As the details emerged, the evidence suggested the substance had been deposited in layers on grains of ice and minerals present in the asteroid.<\/p>\n
It was also flexible \u2014 a pliable material, similar to used gum or even a soft plastic.<\/p>\n
Indeed, during their work with the samples, the researchers noticed the strange material was bendy and dimpled when pressure was applied.<\/p>\n
The stuff was translucent, and exposure to radiation made it brittle, like a lawn chair left too many seasons in the Sun.<\/p>\n
\u201cLooking at its chemical makeup, we see the same kinds of chemical groups that occur in polyurethane on Earth, making this material from Bennu something akin to a \u2018space plastic\u2019,\u201d Dr. Sandford said.<\/p>\n
\u201cThe ancient asteroid stuff isn\u2019t simply polyurethane, though, which is an orderly polymer.\u201d<\/p>\n
\u201cThis one has more random, hodgepodge connections and a composition of elements that differs from particle to particle.\u201d<\/p>\n