NASA's New Horizons mission, which encountered Pluto in 2015 is now riding through the deepest depths of the Kuiper Belt, is encountering a cosmic dust storm that hints there may be more going on in the outermost reaches of the solar system than we imagine.
Space is filled with dust formed of tiny particles just microns — millionths of a meter — in size. Much of the dust in our solar system is leftover residue from the formation of the planets, which was a violent affair that saw a multitude of objects smash into one another. Today, this ancient dust is also joined by fresh dust sputtered off the surfaces of asteroids and comets by micrometeorite impacts. This dust content, both fresh and ancient, gives rise to the enigmatic "Zodiacal light." The dust extends into the farthest reaches of the solar system. Astronomers still are not entirely sure of the make-up of this final frontier.
