This is an activity about astrology and the scientific reasons behind the zodiac cycle. Learners will form a model by sitting in a circle, holding constellation signs, and placing a light source representing the Sun in the middle. Then, using the... (View More) model, they will explain why one cannot see their zodiac constellation or sun sign on their birthday, and predict how long they would have to wait to see it in the nighttime sky. Finally, learners will understand why the ecliptic, which contains the zodiac constellations, changes over time as a result of the Earth's precessional cycle. This is Activity K-1 of Universe at Your Fingertips 2.0: A Collection of Activities and Resources for Teaching Astronomy DVD-ROM, which is available for purchase. (View Less)

This is an activity about the expansion of the Universe. Learners will use a special set of transparency and master sheets with dots representing clusters of galaxies at two different eras of the Universe's history. After aligning the transparency... (View More) and underlying page, learners then observe and measure clusters moving away from particular locations, graph their data, compute a slope and relate the slope to the age of the Universe. This is Actividad 8.4 as part of El Universo a Sus Pies, a Spanish-language curriculum, available for purchase. (View Less)