A scientist suggests painting asteroids with metallic paint to distract them from Earth

Painting an asteroid with metallic paint might be a cheap and effective alternative to keeping it off Earth. The idea, put forward by astronomer Jonathan Katz, of the University of Washington, is to turn a celestial body into a kind of mirror globe (yes, the ones that are characteristic of nightclubs), so that it reflects more light, thus changing its orbit.

Astronomers estimate that every 500,000 years or so, an asteroid about one kilometer in diameter could collide with Earth. For now, we remain safe, but if such an event occurs, we must be prepared to prevent a global tragedy.

a NASA And other space agencies continue to monitor any object approaching our planet. Currently, only 40% of Nearby asteroids known, but the goal is to find out about threats that range in size from kilometers to meters.

missions like The DART (Double Asteroid Redirection Test), launched by NASA In November last year, a spacecraft collided with an asteroid to change its course. But for astronomer Jonathan Katz, coating a celestial body in metal would be a simple and effective alternative for the same purpose.

The colorful asteroid will be pushed by the sun

In practice, the impulse from an asteroid reversal will not be much, but Katz believes that once the object is determined in advance, as well as its trajectory, this force in the long run will be enough to change its orbit.

Small asteroids can be Powered by the Yarkovsky Effect. Basically, the celestial body is heated by the sun’s rays, so it re-emits this energy and acquires a small boost. Katz’s proposal points to a more urgent rush, which should facilitate calculations of its trajectory.

Coating an asteroid’s surface with lithium or sodium could increase its reflectivity. One kilogram of metal is enough to cover the celestial body with a layer with a thickness of a micrometer. “An asteroid 50 meters in diameter can deviate by 3,000 km within a century, or 1,000 km in 30 years,” Katz added.

An alternative method is to cover only half of the asteroid to generate more targeted thrust. “The spacecraft should be in a polar orbit over an asteroid emitting metal in the form of vapor that is able to coat the entire body or parts of it,” Katz said.

The proposal was presented in the scientific journal Earth and Planetary Astrophysics.

source: Astrophysics of Earth and Planets, via Astronomy.com