Context: China is about to launch a space mission called Tianwen-2 to explore a small asteroid named Kamo‘oalewa.
Relevance of the Topic: Prelims: Key facts related to Tianwen-2 Mission.
Tianwen-2 Mission:
- Tianwen-2 aims to explore a near Earth asteroid named Kamo‘oalewa.
- The mission will use touch-and-go technique, which has been successfully implemented by the United States’ OSIRIS-Rex and Japan’s Hayabusa2 missions. In touch-and-go technique, the spacecraft hovers close to the surface of the asteroid, while a robotic arm fires an object or burst of gas to knock fragments into a collection chamber.
- Depending on the surface conditions, the Tianwen-2 probe might also use anchor and attach technique. In this technique, four robotic arms extend and drill into the surface to retrieve material.
- After collecting the samples, the mission will drop them on Earth. The probe will then head towards the main asteroid belt for another mission (towards comet 311P/PANSTARRS). The fragments collected by Tianwen-2 will return to Earth about 2.5 years after the launch.
- If successful, China will join the US and Japan as the third country to bring back asteroid samples to Earth.
Kamo‘oalewa Asteroid:
- It is a near-Earth asteroid discovered in 2016 by the Pan-STARRS 1 telescope in Hawaii. It is quite small, measuring just 40 to 100 metres in diameter.
- It belongs to a rare class called quasi-satellites- celestial bodies that orbit the Sun but remain gravitationally close to Earth.
- It appears to follow Earth’s orbit in a "leading and trailing" motion due to its highly elliptical path. This gives the impression the asteroid orbits Earth.
Significance of the Mission
- Kamo‘oalewa has garnered attention due to its unusual orbit and unknown origin. Scientists believe exploring this asteroid would help them find clues about quasi-satellites, and how their orbits evolved over time.
- Some researchers suggest that Kamo‘oalewa could be the first known asteroid composed of lunar material. The exploration of the asteroid could settle the hypothesis that the Moon was formed as a result of a collision between the Earth and another small planet (Kamo‘oalewa could be a small remnant of that collision).