Out near the orbit of Jupiter, a faint speck of light is moving through the black of space. At first glance it doesn't look like much -- no brighter than a thousand distant stars speckling in the velvet sky behind it. Indeed, it takes a big telescope to make out that it is a comet. But what a comet it could turn out to be... Later this year, "Comet ISON" could blossom into a striking naked eye object visible even in broad daylight. Whether we'll look back on ISON as the "Comet of the Century" or as an over-hyped cosmic dud remains to be seen. But astronomers are planning to learn the most they can about this unusual visitor no matter what happens.