Researchers have recently developed the "most accurate model to date" of solar wind affecting an asteroid - a phenomenon that, you may be surprised to learn, could be very dangerous to unprepared astronauts during asteroid missions planned for the near future.
According to NASA, without their own strong magnetic fields and atmospheres to buffer the effects of solar winds, airless objects like moons and asteroids develop a strong positive electric charge in sunlit areas. This occurs after electrically conducting plasma gas in solar wind ejects negatively charged electrons and positively charged ions from matter.
"While areas in sunlight can charge positive, areas in shadow get a strong negative charge when electrons in the solar wind rush in ahead of heavier ions to fill voids created as the solar wind flows by," NASA reports.
This could prove disastrous for astronauts slated to make contact with a captured asteroid in the near future.
And that's why NASA-sponsored researchers have developed a new computer model that can better visualize and predict interactions between solar wind, solar radiation, and the surface of asteroids.
"Understanding the electrical environment around an asteroid could help identify locations where astronauts can safely make first contact with the object," researcher William Farrell of NASA's Goddard Space Flight Center, said in a statement. "If an astronaut is tethered to a spacecraft that is in sunlight and positively charged, and touches a negatively charged asteroid surface in shadow, there could be an unexpected current flow between the two systems upon contact. We simply can't speculate on the nature of that current without this model."
According to Michael Zimmerman, the lead investigator on this project, his team's new model supports some theories of solar wind flow based off lunar observations - and can predict these phenomena in a tenth of the time of previous models. However, nothing can be verified with finality until an actual mission to an asteroid in the near future.
[Credit: M.I. Zimmerman/W.M. Farrell/A.R. Poppe]