Researchers in Hawaii have discovered an intriguing asteroid named Kamo’oalewa, which they believe could be a fragment of the moon, according to a new study published in Nature Astronomy. The study suggests that this fast-spinning asteroid may have originated from the Giordano Bruno crater on the far side of the moon. The asteroid’s light reflectance, size, age, and spin all align with characteristics of the lunar crater, leading researchers to speculate on its lunar origins.
China is planning to launch a sample-return mission called Tianwen-2 to the asteroid in 2025. The mission aims to bring back pieces of Kamo’oalewa for further study. This unexpected possibility of a lunar-derived origin adds a new level of intrigue to the mission, presenting additional technical challenges for the sample return, as noted by planetary scientist Bin Cheng, one of the study’s co-authors.
Kamo’oalewa was first discovered in 2016 and has a diameter of about 100 to 200 feet, spinning rapidly with one rotation every 28 minutes. Its orbit around the sun is similar to Earth’s path, occasionally coming within 10 million miles of our planet. Follow-up studies have shown that the light spectra reflected by Kamo’oalewa closely resembles that of samples brought back from lunar missions and moon meteorites.
The research team calculated the size and speed of impact needed to eject a fragment like Kamo’oalewa from the lunar surface, pinpointing Giordano Bruno crater as the likely source. By examining young craters on the moon, the team narrowed down potential contenders, ultimately focusing on Giordano Bruno as the most probable origin of the asteroid. Confirmation of this theory will come after the Tianwen-2 mission retrieves a piece of Kamo’oalewa for further analysis.
Researchers are eager to compare the asteroid with samples believed to be ejecta from the Giordano Bruno crater brought back to Earth in a past NASA mission. This comparative analysis will help verify Kamo’oalewa’s lunar origin, shedding light on the mysterious connection between the asteroid and the moon.