Related Clues:

• Van Gogh's "— Night"
• Like a night on which the Big Dipper is visible
• Black stuff in hole visible at night
• Subject to lunar illumination
• Like a night sky away from city lights
• Unusual monolith briefly illuminated at night
• Doctor left it after working under night-time conditions?
• Sparkling son has to wait
• Brighter at night?
• Naturally illuminated at night
• Repeated description of the night, in Don McLean's Vincent?
• Like the clear night sky