Entry No. 59 — the Chicago file — filed under: after-dark

Dearborn Observatory (Northwestern University)

Inside a domed 1888 limestone building on Northwestern's lakefront campus lives an 18.5-inch refractor that was once among the largest in the world. Every Friday night the dome cranks open and physics and astronomy volunteers walk small groups up several staircases to look through the antique brass-and-glass instrument, free of charge, rain or shine. The dome has no heat or air conditioning, so the experience changes dramatically with the season.

The move: Reserve the early Friday hour, climb up to the historic refractor together, and let a grad student point it at whatever is highest in the sky that night.

📍 Before you go Free Friday nights (9-11pm spring/summer, 8-10pm fall/winter); first hour is reservation-only. Not ADA-accessible due to staircases. Cloudy nights still run as building tours.

• 📍 Evanston
• 💸 $
• ⚡ Low-key
• 🌗 Outdoors

Where: 2131 Tech Dr, Evanston, IL 60208

Hours: Added 2026-06-23 — confirm current hours before you go.

⚠ Seasonal or scheduled — always check before you go.

Plan a visit & invite your people →

Proof: source 1 · source 2 · source 3 · source 4

last checked: 2026-06-23