Possible Clues:

• Where 5 10 is unable to be made out
• Gaseous cloud
• 'The world of existence to him seemed to have lazily melted down into a mere —' (Dinah Maria Craik, John Halifax, Gentleman)
• Orion ___
• Cloud of gas or dust in space
• Annual science fiction award
• Ophthalmologist is looking into The Cloud
• A lot of moonshine filling most of neighbouring astronomical object
• Space cloud of gas and dust
• Gassy, dusty cloud