The Japan Aerospace Exploration Agency, or JAXA, said Hayabusa2 dropped a small explosive box which sent a copper ball the size of a baseball slamming into the asteroid, and that data confirmed the spacecraft had safely evacuated and remained intact. JAXA later confirmed the impact from images transmitted from a camera left behind by the spacecraft which showed the impactor being released and fine particles later spraying dozens of meters (yards) out from a spot on the asteroid.
AP
April 5, 2019. A day that will live in famy. But NASA beat them for the first deliberate crash into an asteroid. Deep Impact in 2013. The technology should come in handy though for future asteroid deflection missions to fend off the kind of event that killed the dinosaurs. Here’s an overview of the technology.
Most deflection efforts for a large object require from a year to decades of warning, allowing time to prepare and carry out a collision avoidance project, as no known planetary defense hardware has yet been developed. It has been estimated that a velocity change of just 3.5/t × 10−2 m·s−1 (where t is the number of years until potential impact) is needed to successfully deflect a body on a direct collision trajectory. In addition, under certain circumstances, much smaller velocity changes are needed
Wikipedia
Back in the ’50s there was a plan to nuke the moon.
The recent Chelyabinsk meteorite was the second atomic bomb sized object to hit Earth within a 100 yearWikipedia