Earth’s Second Moon Could Be a Lost Piece of the Moon, Scientists Say
The Daily Galaxy • • science
Key Points:
- Astronomers have debated whether Earth's co-orbital asteroids like 2016 HO3 and Kamo’oalewa are lunar fragments or main-belt asteroids, with recent simulations favoring an asteroid belt origin.
- Kamo’oalewa's surface composition resembles lunar silicates, fueling speculation it could be debris from the moon, possibly ejected by the impact that formed the Giordano Bruno crater.
- Simulations show that the likelihood of a lunar fragment achieving a stable quasi-satellite orbit is extremely low, with an estimated 21% chance of lunar origin, making the asteroid belt hypothesis more probable.
- Supercomputer models tracked thousands of particles launched from the moon and predicted only a few could maintain stable co-orbital orbits, whereas models from the asteroid belt suggest a much larger population of potential co-orbitals near Earth.
- Future spacecraft missions aiming to return physical samples from these co-orbitals may provide definitive evidence about their origins.