Nearly 20 year-old software used to protect humanity gets an upgrade
NASA has upgraded its near-Earth asteroid monitoring algorithm to model hazardous space rocks more accurately after nearly two decades, it announced on Tuesday. The new system, dubbed Sentry-II, is more powerful than its predecessor, Sentry. Astronomers working at the space agency’s Center for Near Earth Object Studies can now automatically calculate thermal influences that nudge an asteroid’s orbit, potentially sending it hurtling towards our home planet. The so-called Yarkovsky effect describes the subtle and gradual change of motion when asteroids are heated by the Sun’s light. When asteroids spin, one side of its surface exposed to the star gets heated. As it continues to rotate, the hot region enters shade and cools down. Infrared energy is radiated outwards; the photons carry momentum and impart a tiny thrust on the asteroid. Over long periods of time, these small kicks can change their paths and knock them out of their original orbit. Although NASA’s old Sentry system could adjust orbital calculations for an asteroid by considering the gravitational effects of the Sun and planets as it whizzed around space, it couldn’t take other external factors into account like the Yarkovsky effect.
