Pluto
...aves a torus around Jupiter, and the Moon is believed to have a tail made of sodium. The skeptics like to think of Pluto as a large comet, but again think of its size. Remember Comet Hale-Bopp's appearance in our skies several years back? What a surreal impression it made, as it hung in the sky. One could understand how the ancients believed comets were a sign of doom. But Hale-Bopp was only 25 miles in diameter! Imagine a comet 1,500 miles in diameter and the same distance from the Earth. I think that if we encountered an object of that magnitude, we'd all head for the hills! Better yet, imagine Comet Pluto being the same distance that Comet Hyakutake was, just 9 million miles away. Wouldn't the media proclaim a "worlds in collision" sort of event? Wouldn't Comet Pluto be a dazzling object in the daytime sky? Wouldn't high tide be a little higher? Wouldn't the stock market be a little crazier? And wouldn't Neil Tyson be a regular on the evening news? Pluto is very different from other planets. It may even be what you could call a proto- planet, a planet nearly formed, what our planet may have been in the beginning before the Sun shone. But until another pathfinder comes its way, the Pluto Express mission perhaps, Pluto should keep its planetary status. It is a world like many others in the solar system. First, it has an atmosphere of methane and nitrogen, though very tenuous. It may even have primitive weather. Second, it has a moon, Charon, which swings around it in a tight orbit. Its tidal interaction with the moon Charon may produce pools or lakes of liquid nitrogen and underground water-ammonia oases. And most important, Pluto is not only spherical, but is also larger than most moons, and all comets and asteroids. Pluto probably looks and is similar to Triton, moon of Neptune, which was probably a rogue planet itself once. Had Voyager ...