First Unprecedented Photos of Earth's 'Second Moon' Obtained

For the first time, humanity has obtained unprecedented close-up photographs of Kamoʻoalewa, the enigmatic object referred to as Earth's "second moon." These historic images were captured by China's Tianwen-2 mission, which is currently studying this small celestial body to unravel its origins and composition.

While often called a "second moon," Kamoʻoalewa is not a natural satellite. It is classified as a quasi-satellite, meaning it orbits the Sun on a trajectory closely mirroring Earth's, allowing it to remain in proximity to our planet for significant durations. Its name originates from the Hawaiian language, as it was first discovered in 2016 by a telescope in Hawaii. Since then, its peculiar orbital characteristics and potential connection to the Moon have intrigued the scientific community.

Unlike Earth's natural moon, Kamoʻoalewa does not orbit our planet directly. Its movement is primarily governed by the Sun, yet its orbit maintains a very close relationship with Earth's. Astronomers estimate its diameter to be between 40 and 100 meters, making it one of the smallest space objects ever visited by a scientific mission. Its orbit brings it relatively close to Earth approximately every 45 years, engaging in a gravitational "dance" as both bodies traverse the solar system.

The detailed images were acquired by the Tianwen-2 probe, China's inaugural space mission dedicated to asteroid study. Launched in 2025, the spacecraft traveled approximately one billion kilometers to reach Kamoʻoalewa. Upon arrival, it maneuvered to within about 20 kilometers of the object's surface, enabling the capture of the most detailed photographs ever recorded. The mission will continue its observations for about a year before attempting a complex maneuver: collecting samples of the space rock for return and analysis on Earth. A key question researchers aim to answer is Kamoʻoalewa's origin, with some studies suggesting it could be a fragment of the Moon ejected by a massive meteorite impact millions of years ago.