The Uranus Puzzle
The Uranus Puzzle
This Demonstration deals with the orbits of the planets Uranus and Neptune. It allows us to reenact a highlight of nineteenth-century astronomy. During the period 1781–1846, when Uranus had been discovered, whereas Neptune was still unknown, astronomers were puzzled by the observed motion of Uranus. It turned out that it was impossible to set up initial conditions for Uranus which together with the forces from the Sun, Jupiter, and Saturn would result in an orbit consistent with observation for more than a few decades (from old stellar catalogs Uranus positions had become available back to 1690). The idea was born that a trans-Uranian planet might cause the anomaly of Uranus' orbit and that a thorough analysis of these anomalies should allow one to calculate the position of the causative planet. As is well known, this program worked, and the computational results of Urbain Le Verrier triggered the discovery of the planet, which finally was baptized Neptune. This Demonstration simulates this Uranus orbit puzzle and lets us solve it by proposing a suitable celestial body. With some trial and error we can do much better than Le Verrier and come much closer to the true properties of Neptune.
The action of each control is described by a tooltip.