Possible Clues:

• Subject to lunar illumination
• Like a romantic evening stroll, perhaps
• Erratic motion around Lagrange point as revealed by satellite
• Show bottom student that item with heavenly illumination
• Ripe for romance, as a stroll
• Low dipstick gathering last drop of oil, visible when dark
• Argue about Northern Line, one not seen in the brightest light
• Milton has nothing scene, say, at night
• Low source of luminance one found in extremes of night -- like this?
• Low walls of national interest illuminated by night