DART is not the only option to defend the planet: and paint the asteroid in another color?

NASA is studying other options to divert the trajectory of one of the thousands of asteroids that could hit EarthChanging the color of the asteroid is one of them: it could generate changes in its interaction with the Sun and in its trajectory Launch a nuclear missile, although it is the favorite option of Hollywood, it is the most risky and it would be only a last resort It has been a success. But it is not the only way to do it. Using a ship to hit an asteroid and divert its trajectory, which the DART probe did this morning, is just one of the options that exist. There is more. Some easier, others almost unlikely. “Other options have been studied,” Lindley Johnson, NASA’s planetary defense officer, explained last week. “We have a list of three or four that we would like to try in the future,” he assured at a press conference. What are they? The “gravity tractor” This option consists of using what NASA calls a “gravity tractor”: launching a heavy spacecraft to fly alongside the asteroid. That generates a slight gravitational attraction of the asteroid towards the ship. If that attraction can be sustained for a while, it may be enough to pull the asteroid out of a possible collision course with Earth. “The mutual attraction between the spacecraft and the asteroid will slowly drag that asteroid out of its impact path and will lead to a more benign one,” Johnson explains. “But this technique takes longer to implement, so we would have to be warned in advance to be able to carry it out.” of binary asteroids in which Dimorphos orbited. Ion thrusters have been used for decades in space exploration, using electric fields to accelerate a beam of charged atoms, usually xenon. They generate little thrust, but that thrust is constant, over long periods of time. As with the “gravity tractor”, the idea is that generating slow changes in the asteroid’s trajectory, but sustained over time, can be effective. Paint the asteroid and ally with the Sun But there is more, and this would be the most surprising option: paint the asteroid and then let the Sun do its job. How they hear it. Because changing the color of the asteroid may involve changes in how much it heats up in sunlight, and in the pressure exerted by photons of sunlight bouncing off its surface. And this can also mean a change of direction, over time. Nuclear missiles: the riskiest option There is still another option to try to deflect an asteroid. And it’s Hollywood’s favorite, so it may be the one that most resonates with them: nuclear weapons. It can work, but for NASA it would be, rather, a last resort, a desperate measure if there was no time for “more moderate” options, explains the American newspaper The New York Times. Because in this case, we are talking about making the asteroid explode . And it may not be the solution, if all the pieces end up hitting Earth afterwards, throwing the same amount of energy into the atmosphere and generating a tsunami of shock waves. Asteroids are not simple objects in structure or composition, so that it is not easy to accurately predict the effects of a bomb dropped on them. Could it work though? It looks like it is. Last year, scientists at the University of Maryland found, at least on paper, that an asteroid up to 100 meters in diameter could be annihilated by a one-megaton nuclear missile, diverting 99.9% of its mass away from Earth. Land. Of course, the missile should be launched at least two months before impact. 5,000 “potentially dangerous” asteroids Having these other options on the table is important. Because NASA estimates that there are about 20,000 that could impact our planet. Although they do not pose a real danger, at least in the next 50 years, there are 5,000 of them that he describes as “potentially dangerous”: asteroids that exceed 140 meters in diameter and that are located less than 10 million kilometers from Earth. Dimorphos, 160 meters, was more than 11 million kilometers from our planet, so it did not pose any danger. But it has served as a “guinea pig” to verify that yes, we can avoid a possible impact of these space rocks. And this little asteroid has unknowingly made history.