Travel for less for Immediately around the nucleus is the brightest region of the coma, known as the pseudonucleus. Comas may be anything from very small to mind-bogglingly massive. In space, the diameter of Hale-Bopp’s coma is reckoned to have been twice the diameter of the Sun in , and Comet Holmes grew to be more than times the diameter of the Sun in ? . From the perspective of Earth, comas can look extremely large, because they really are huge in space and/or because they are so close to us. Due to the fact that they made especially close approaches to Earth, the relatively small comets Hyakutake with a nucleus about km in diameter in and Lexell in appeared respectively to be and ? times the diameter of the Sun. If the large comet Hale-Bopp had come closer to the Sun and Earth, it would have appeared to be something like or degrees in diameter when AU away from Earth and considerably larger if nearer still. Astronomers believe that Earth’s skies hosted countless comets with huge, bright comas in the past. Travel for less 2016.