Astronomers Simulate 24 Planets Orbiting in Unison Like Pearls on a String.
Earth and seven other planets revolve in our Solar System, each following its own unique orbit. However, other star systems may host two, three, or even 24 planets trailing each other along the same orbit around their host star, as reported by Popular Science on May 3rd.
The number of planets sharing the same orbit around a host star can reach 24. (Image: BBC).
A computer simulation by a team of international astronomers illustrates how more than twenty planets can share the same orbit, as detailed in a study published in the Monthly Notices of the Royal Astronomical Society. This configuration could remain stable for billions of years, possibly even longer than the star they orbit, according to lead researcher Sean Raymond at the Bordeaux Astrophysics Laboratory.
There are several examples of small celestial bodies sharing an orbit. Our Solar System features some unusual orbits known as horseshoe or tadpole orbits, depending on their shapes. The Trojan asteroids share a tadpole orbit with Jupiter at points ahead of and behind the gas giant. Two of Saturn’s moons, Janus and Epimetheus, orbit the planet in a horseshoe pattern and periodically swap positions. Therefore, researchers suggest that there may exist exoplanets that share the same orbit.
Raymond and his colleagues’ simulations also revealed that co-orbiting planets exhibit distinctive signals that astronomers on Earth can observe. The Kepler Space Telescope and several other observatories can detect Transit Timing Variations (TTV), where the gravitational pull between nearby planets slightly alters when they pass in front of their host star. TTV from a star system containing 24 Earth-sized planets sharing the same orbit would be significant enough for astronomers to observe. However, it would take months to years of monitoring to detect such effects, according to astronomer Rob Zellem at NASA’s Jet Propulsion Laboratory.
