Solar wind selectively destroys specific organic compounds on asteroid surfaces

Laboratory experiments simulating solar wind exposure on a carbonaceous meteorite revealed that charged-particle radiation selectively destroys specific organic compounds. Tech Times reported that helium ion bombardment preferentially breaks down aliphatic hydrocarbons, which are straight or branched open chains of carbon atoms, while leaving aromatic hydrocarbons based on stable carbon rings largely intact. The study was published on October 31, 2026, in the Journal of Geophysical Research: Planets. [1]

Researchers conducted the experiments on a pristine slice of the Murchison carbonaceous meteorite to simulate approximately 800 years of solar wind exposure. Tech Times reported that the bombardment altered the chemical composition of the meteorite surface. This selective destruction causes reflectance spectra gathered from carbonaceous C-type asteroids to systematically underestimate their true aliphatic hydrocarbon content. [1]

The finding provides critical context for analyzing space missions that observe or retrieve material from asteroids. According to Tech Times, remote spectroscopic observations of asteroid surfaces reflect space weathering rather than the true bulk composition of the bodies. Samples returned directly from celestial bodies, such as those collected from asteroid 162173 Ryugu, help scientists compare altered surface layers against pristine subsurface material. [1][3]

The Hayabusa2 mission, operated by the Japanese space agency JAXA, collected samples from Ryugu and returned them to Earth in December 2020. The spacecraft previously surveyed the asteroid for 18 months starting in June 2018. Understanding the bias in surface spectra helps researchers properly evaluate the pristine organic molecules preserved within early solar system objects. [1][3]