Oh Heavens! A Three-Planet, Figure-8 Orbit Works in Einstein's Universe

May 11, 2007

In principle, three (or more) equal-mass planets looping endlessly in a figure-8 pattern is a possibility — even under the exacting conditions of Einstein's general theory of relativity, say researchers at Japan's Hirosaki University.

In the early 1990s, University of New Mexico physicist Cristopher Moore postulated that, under Newtonian physics, three planets could forever chase each other in a figure-8 orbit. Whether such an idea would fly under Einstein's theory remained a question mark — until now. Taking into account gravitational warping of time and space, Hideki Asada, Takamasa Chiba, and Tatsunori Imai demonstrated that a planetary trio could accomplish a figure-8 orbit. Their results are slated to appear in Physical Review Letters.

According to a report in Science Now, theoretical physicist Luc Blanchet, from the Institute of Astrophysics in Paris, confirmed the result, calling it "amazing." But, he said, "don't expect" the figure 8 to last. Circulating planets generate space-time ripples, allowing energy to radiate away. Eventually, any trio of planets would be unable to sustain such a singular — and beautiful — orbit.

Source: Science Now