Twinkle, Twinkle, Nighttime Sky:How I wonder what you are let's explore beyond our star! Everyday, the sun sets and the sky grows dark. Twinkling stars start to shine, and we watch the moon as it changes phases throughout the month. But the sky we see each night is only a small piece of our huge universe. What else is out there in the nighttime sky? Twinkle, Twinkle, Nighttime Sky is the second board book in the Skytime series, following Twinkle, Twinkle, Daytime Star. Based on the