NASA is planning to deflect an asteroid in 2022 — to learn how to protect Earth

Joseph Stromberg in Vox:

This is all part of a joint mission NASA's planning with the European Space Agency called Asteroid Impact & Deflection Assessment (AIDA). It will start with the launch of a European craft in 2020 to study and map the asteroid first. ESA entered the preliminary design phase of that initial reconnaissance mission earlier this week.

The goal is to develop the technology and expertise that might be necessary to nudge an asteroid out of its orbit if we ever discovered one heading for Earth. It might sound far-fetched, but the truth is that asteroids are apotentially serious threat — and foresighted missions like this could theoretically be the difference between a closely averted disaster and catastrophe.

In 2020, the European Space Agency plans to launch its Asteroid Impact Mission, or AIM probe. It'll travel to an asteroid named Didymos, which is orbited by a relatively small (about 550 feet wide) asteroid called Didymoon.

Over the course of a year or so, AIM will orbit Didymoon, mapping its surface and collecting data on its mass and overall structure. Current plans also call for it to send out a pair of smaller satellites to collect more data, as well as a lander that would touch down on Didymoon itself — becoming just the fourth craft (if Japan's current Hayabusa-2 mission is a success) to make a controlled landing on an asteroid.

More here.