Once upon a time, there was a little girl named Lily who loved space and stars. She learned about parallax in her astronomy class and was fascinated by the way scientists used it to measure distances between stars. One day, while observing through her telescope, she discovered a pulsar that sent out rhythmic beams of light. She also learned about photometry, the study of measuring brightness of celestial objects.

Lily was amazed to learn about the tiny particles called photons that carry light and the particles called protons that make up the nucleus of an atom. She learned about quasars, bright objects in the universe that emit massive amounts of energy, and was amazed that they could be billions of light-years away.

Lily also learned about radians, a unit of measurement for angles, and how it related to the radius of a circle. With her newfound knowledge, Lily went on many amazing space adventures, discovering new wonders of the universe every day. The end.

Reflections

1. What is parallax and how does it relate to measuring distances in space?
2. What is a pulsar and what makes it special?
3. How do photons and protons differ from each other?
4. What is a quasar and why are they important in studying the universe?
5. What is the relationship between radians and the radius of a circle?