Our planet is in close proximity to thousands of Near-Earth Objects (NEOs), some of which are potentially hazardous asteroids (PHAs) and carry the risk of impact on the Earth that could lead to devastating consequences and loss of life.
One of the possible ways to prevent PHAs from colliding with the Earth is to bombard the asteroid with nuclear or thermonuclear charges. However, this method is fraught with the fact that our planet will be in the rain of radioactive debris.
A new softer method, developed by Flavian Venditti of the Arecibo Observatory and the University of Central Florida, proposes to change the trajectory of a potentially dangerous asteroid by tying it with a strong cable to another small celestial body. According to Venditti, the center of gravity of such a system will shift, and, consequently, the orbit of PHAs will also shift.
The researchers tested their idea using a computer model. The object for it was the near-Earth asteroid (101955) Bennu, which with a probability of 1: 4000 may collide with the Earth in the second half of the XXII century. Calculations have shown that the tether system is indeed capable of changing the trajectory of a celestial body without additional energy consumption.
One likely drawback of this method is the fact that it may require a longer execution time than many high impact methods that rapidly deliver kinetic energy to PHAs to knock it out of orbit. So, according to the calculations of the researchers, it will take decades to change Bennu's orbit.