by Kirsti Melto
Lately we have learned about rare visitors, interstellar objects passing through our solar system. First there was ‘Oumuamua, the “first distant messenger,” which was already heading away from the Sun when it was discovered in October 1917. Then in August 2019 came Comet Borisov. Surprisingly there is one that has been with us all along and aims to stay, namely asteroid 514107 Ka’epaoka’awela.
The Full Moon in Gemini happens on Dec. 12, 2019. Opposite the Moon in Sagittarius is the unusual asteroid Ka’epaoka’awela in conjunction with the Sun. Ka’epaoka’awela is outstanding in many ways.
Ka’epaoka’awela’s orbit is retrograde. In other words, it moves in the opposite direction to most other bodies in the solar system. It is in a resonant, co-orbital motion with Jupiter. It is the first known asteroid in a 1:1 resonance with any of the planets. Its orbital period around the Sun is close to that of Jupiter.
How come Ka’epaoka’awela avoids crashing into the gas giant Jupiter? It passes either inside or outside Jupiter’s orbit, and each time it passes near Jupiter, its orbital elements are slightly altered. Scientists have concluded that Ka’epaoka’awela is originally an interstellar body and it has been in its retrograde resonance with Jupiter since the origin of the solar system. How it got captured into its orbit is still a mystery.