Chapter 2 — Motions of Heavenly Bodies
Astronomy learning hub
HTML5 versions of the UNL ClassAction / NAAP lab animations. Hong Kong is the default observer. No science background required.
Motion of Stars
Earth's rotation makes stars rise in the east and set in the west. Near Polaris, circumpolar stars never set.
Open simulator →Motion of the Sun
The Sun moves along the ecliptic through the zodiac, creating seasons and changing day length.
Open simulator →Motion of the Moon
The Moon's synodic month is about 29.5 days. Its phases follow its position relative to the Sun.
Open simulator →Motion of Planets
Inner planets swing near the Sun; outer planets show retrograde loops when Earth overtakes them.
Open simulator →