China's Tianwen-2 probe reaches asteroid Kamoʻoalewa for sample collection

China's Tianwen-2 spacecraft has arrived at the near-Earth asteroid Kamoʻoalewa (2016 HO3) after a 400-day, 1-billion-kilometer journey, marking the country's first attempt to collect samples from an asteroid. The probe is now 20 kilometers from the rocky body and has begun scientific observations to prepare for sampling, with sample return expected in 2027. Source: CNA

Size surprise

The asteroid appears smaller than earlier estimates. Initial predictions suggested a diameter of 40–100 meters, but the first close-up image indicates it may be only 20–30 meters across. Source: SCMP Gizmodo reports a width of just over 66 feet (20 meters). Source: Gizmodo This smaller size could make sampling "far more difficult" than previous missions to larger asteroids like Ryugu and Bennu. Source: SCMP

Sampling and objectives

Tianwen-2 carries 11 scientific instruments and is capable of three sampling techniques to adapt to the asteroid's unknown surface. Source: Gizmodo Scientists suspect Kamoʻoalewa may be a fragment of the Moon, based on spectral analysis and crater studies. The mission aims to collect 20–100 milligrams of material to test this hypothesis. Source: Gizmodo

Broader context

The mission is part of China's "space dream" to catch up with the US and Europe in deep-space exploration. Source: DW News After dropping off samples, the spacecraft will continue to comet 311P/PANSTARRS, arriving by 2035. Source: Gizmodo