The term 'Orbiter with a Tail' is referring to a COMET, which is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, creating a visible atmosphere or coma, and sometimes also a tail. Comets have been observed since ancient times and are popularly thought of as 'dirty snowballs' made up of loose collections of ice, dust, and small rocky particles.