Sunrise+Sunset Observation

Recently, the days have been getting longer. Sunrise comes earlier and sunset occurs later. Looking at the recent [rapid noticeable] elongation of the day in March, and how the temperature is rising rapidly, we can guess that we sit on the smaller-sector side of our orbital ellipse.

From Kepler's second law, "A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time."

Verifying on a seasonal orbit diagram for March, we are indeed closer to the periapsis than the apoapsis.

Working backwards from experimental data may have resulted in deducing an elliptical orbit, eventually leading to how these laws were established.

source: http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Seasons1.svg/2000px-Seasons1.svg.png

http://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion