The Celestial Sphere and Star Charts: Practice Problem Solutions

1. They are the points where Earth's axis, extended into space, meets the celestial sphere. The north celestial pole is near Polaris; the south celestial pole is in the opposite direction.

2. The ecliptic is the Sun's apparent yearly path through the stars (really Earth's orbit seen from Earth). It is tilted about 23.5 degrees to the celestial equator because Earth's axis is tilted by that amount.

3. Declination corresponds to latitude and right ascension corresponds to longitude.

4. Earth turns 360 degrees in about 24 hours, which is 15 degrees per hour.

5. The sky around the south celestial pole, including famous southern constellations like the Southern Cross.

6. To find which stars and constellations are visible at a given date and time by turning the dial to match.