MadSci Network: Astronomy |
The earth rotates from east to west: that's the reason the sun rises in the east and sets in the west. So that fact doesn't change if you're observing sunrises/sunsets in the southern hemisphere. Whether it arcs across the northern or southern part of the sky in the southern hemisphere depends on the observer's latitude. From December 21 or 22 to March 20-21, the sun passes directly overhead at noon, from latitudes 22.5 South to the equator. So, for an observer in the southern tropics, he may see the sun span across to the north or south, depending on the time of the year. Imagine yourself at a specific spot on a globe and use a light bulb as the sun. So for example if you're in Lima, Peru (13 S) for Christmas when the sun is at the zenith at noon in Rio (22 S), the sun will rise slightly to the south of east, arc across the southern sky and set slightly to the south of west. But in the spring when the sun is at the zenith at noon above the equator, the sun in Lima will rise slightly to the north of east, arc across the NORTHERN sky and set slightly to the north of west. For latitudes below 22S, then the sun will always arc in the northern part of the sky between sunrise and sunset. Enrico Uva
Try the links in the MadSci Library for more information on Astronomy.