Dart hits bull's eye, more to follow

NASA's spacecraft Dart rammed into an asteroid 11.3 million kilometers away at a speed that altered the asteroid's orbit and lowered its cycle period by 15 minutes, the space organization announced on Monday.

Some said the move shows the world might now be able to prevent asteroids — the kind that made the dinosaurs extinct — from hitting the Earth. The asteroid that was controlled belonged to a double-asteroid system. It had a 160-meter diameter while the other asteroid's diameter is over 500 meters. The bigger asteroid can be compared to the one that ended the dinosaur era 67 million years ago. A hit from an asteroid that size can cause unimaginable destruction.

However, it is too early to assert that the world has gained the ability to prevent asteroids from hitting us. The asteroid that was controlled was only 160 meters in size. Its cycle period was changed, without changing its orbit significantly. It is still not clear if the orbit of a much larger asteroid headed toward the Earth can be altered as successfully.

In a nutshell, NASA's success in altering the course of a harmful asteroid is definitely commendable, but much more needs to be done before we can say the world's security from some erratic asteroid is foolproof.

It should be noted that changing the orbit of an asteroid involves more than just sending an object into space and commanding it to hit the asteroid. While it is hard enough to hit an asteroid, it is even more difficult to lock onto one in the first place. It means having the ability to observe approaching asteroids, measuring their respective speeds, and deciding which ones might pose a danger to the Earth.

Therefore, there's more to Dart hitting the asteroid than meets the eye. And these are key areas where global scientists need to work harder in the future.

— SHI HAO, AN ENGINEER AT CHINA AEROSPACE SCIENCE AND TECHNOLOGY CORPORATION