New Scientist reports that a new strategy developed by NASA astronaut Edward Lu to stop asteroids involves placing a massive object, likely a huge spaceship, near the incoming asteroid and use gravity to pull the object out of an orbit that will hit planet Earth.
Lu’s team finally realised that the spacecraft might not need to land at all. Placing a heavy enough object near the asteroid for long enough could produce sufficient gravitational tug to change its orbit.
For a 200-metre-wide asteroid, the spacecraft would need to weigh about 20 tonnes and lurk 50 metres from its target for about a year to change its velocity enough to knock it off course.
"This is hands down the best idea I have seen," says Erik Asphaug, a planetary scientist at the University of California at Santa Cruz. "This will work, but you need to put a large enough spacecraft out there at the right time."
The article also said that Lu thinks creating spacecraft that are large enough is perfectly feasible. Obviously you would need to have construction plans in place well ahead of the asteroid's impact date which is why discovering asteroids that might strike Earth is such an important field of astronomy.
