After a journey of some 1 billion kilometers over roughly 400 days, China’s Tianwen-2 spacecraft has reached Kamoʻoalewa, a small asteroid that shadows the Earth as a “quasi-moon,” the China National Space Administration announced July 6. Space News reports that CNSA released humanity’s first close-up image of the roughly 20-meter rock, an elongated body that some suspect is a stray fragment of our own Moon, a question the mission may finally settle. Tianwen-2 will now attempt to seize a sample by one of three methods and return it to Earth in 2027, before pressing on toward a comet.
To learn what the near-Earth object is made of and how it holds together—loose rubble pile or solid rock—is the type of knowledge that will help develop the ability to deflect one that might, someday, be on a collision course. This is the Strategic Defense of Earth in practice: not the war of nations against each other, but the common enterprise of a humanity able to reach across the solar system to guard our shared home.
