Scientists Capture First Close-Up Images of Earth's Second Moon

Chinese astronomers have captured the first close-up images of a mini-moon that has been orbiting around the Earth. Here is a look at the mission and what it hopes to discover.

First Images of Earth's Mini-Moon Released

While astronomers have been referring to 2016 HO3 as a mini-moon, the celestial body is actually an asteroid orbiting the sun. Also known as Kamo'oalewa, this space rock only comes within close orbit of Earth every 45 years, making it one of seven known quasi-satellites to circle our planet. 2016 HO3 is distinguished as the closest of the seven satellites, spinning about 25.8 million miles away from the surface of Earth.

According to the China National Space Administration (CNSA) mission, the Tianwen-2 probe traveled a distance of 621 million miles over 400 days to come within 12.4 miles of 2016 HO3. The mission originated at the Xichang Satellite Launch Center.

Scientists are hopeful that the mission will provide information about the composition of HO3. The probe could also answer questions about the asteroid's orbit, whether it is home to water, and more. There is also the possibility that astronomers may learn if this asteroid was once part of the moon.

Astronomers warn that the recon effort is a bit of a challenge. The small size of the mini-moon makes it more difficult to sample compared to larger celestial bodies. Exacerbating the challenges is the fact that the small asteroid is also spinning at a rate of one full revolution per 28 minutes, making it a difficult target when trying to capture data. Lastly, the uneven gravitational field and the rocky terrain of the surface pose even more challenges.

There is a chance that the probe could bounce off the rapidly rotating target when trying to make a landing. As such, the team of scientists is using special hovering and anchoring capabilities on the probe to help to collect the samples. CNSA noted that “Tianwen-2’s mission is far more complex than previous deep-space explorations and represents a completely new path for humanity’s exploration of the universe."

Despite all of the challenges in gathering the data, the scientists believe that the mission will possibly answer “fundamental questions about the origins of Earth’s quasi-satellites and the dynamical evolution of their orbits.”