-- I am like a slip of comet,That master comet discoverer David Levy has convincing shown that the lines were inspired by Hopkins' observation of Comet Tempel about a month earlier. Tempel was the first comet to be observed spectroscopically. But what about that phrase "To single Saturn, last and solitary?" In 1864, Saturn was known to be neither last nor solitary. But the poem was meant to be a speech in a play set in Renaissance Italy, before the discovery of Saturn's rings or moons, and before the discovery of Uranus, Neptune or Pluto.
Scarce worth discovery, in some corner seen
Bridging the slender difference of two stars,
Come out of space, or suddenly engender'd
By heady elements, for no man knows;
But when she sights the sun she grows and sizes
And spins her skirts out, while her central star
Shakes its cocooning mists; and so she comes
To fields of light; millions of travelling rays
Pierce her; she hangs upon the flame-cased sun,
And sucks the light as full as Gideons's fleece:
But then her tether calls her; she falls off,
And as she dwindles shreds her smock of gold
Amidst the sistering planets, till she comes
To single Saturn, last and solitary;
And then goes out into the cavernous dark.
So I go out: my little sweet is done:
I have drawn heat from this contagious sun:
To not ungentle death now forth I run.
And, last evening, a slip of Moon, Amor's bow, shooting its arrow straight into the setting Sun.