Defining a fatal asteroid has become much less dangerous

If an asteroid was heading for a deadly impact with the earth, could we push it out of the course without aggravating the situation? Yes, thanks to a new system to calculate the perfect place to hit a spacecraft in an incoming asteroid.

Directing an asteroid to Earth is a business with high issues, and we did not have much practice. In 2023, the NASA double asteroid redirection test (DART) showed for the first time that we can divert a space rock by breaking a small probe in the tiny asteroid dimorphos, which orbit a larger asteroid called Didymos and by modifying its 30 -minute orbit.

But such a maneuver is not without risk. The displacement of an asteroid in a new orbit can in turn push it through a small window, called gravitational lock hole, where the gravity of a larger body as the earth can change its orbital path enough to make it boomerang and strike the planet to a later date.

Now Rahil Makadia at the University of Illinois in Urbana-Champaign and his colleagues have developed a system to locate the ideal place for a collision satellite in order to minimize this risk. The team used data collected from the DART mission, as well as information on the form, mass and speed of rotation of an asteroid, to predict how different impact locations modify the asteroid path. This can be used to produce a probability map of the surface of an asteroid, each point giving a different chance of pushing the object through a gravitational lock hole. Scientists can then choose the lowest probability impact site.

“The mapping of these key holes on asteroids is possible and everything it costs even before the mission is lifted by the computing power, so we should do so to make sure that we can choose the best possible targeting point on the surface of the asteroid for any kinetic impact,” said Makadia on September 9.

Makadia and her team tested their method on the Bennu asteroid, identifying more than 2,000 key holes possible to produce a map of locations that could be safe with a spacecraft.

The collection of specific information for an asteroid would be better achieved with a personalized probe sent to collect information, but that may not always be possible if the asteroid was discovered near a potential impact of the earth. However, an approximate analysis should always be possible using information from telescopes on earth, explains Makadia.

A safe test for the collection of this type of data will be when the Apophis asteroid made an extraordinarily close to the earth in 2029. Astronomers calculated that the space rock 450 meters long does not pose any risk for the earth, but an object of its massage in mass so close to the earth is an event of 1 over 7500 years, So Astronomers is ready to obtain space missions to intercep the tram in the four years.

“We have seen a lot of asteroids, but we have never seen an asteroid undergo this type of stress and natural vibrations of the gravitational force of the earth,” Richard Binzel told Massachusets Institute of Technology at EPSC on September 8.

The two Osiris-Apex spacecraft of NASA, which initially visited the asteroid Bennu, but which has now been redirected to visit Apophis, and the European spacecraft spacecraft will be, hopefully, ready to see the asteroid when it passes on the ground.

In addition to orbit the asteroid at a safe distance and collect key information such as its composition and its shape, astronomers also hope to land with a small small -sized 4 -size entrepreneurs on its surface to measure what is happening in its interior, including a long -term seismic activity which occurs when an asteroid passes near a large body like the earth.

Understanding these properties for a future asteroid threatening the earth could be crucial, said Binzel. “If we had to face a threat of real asteroid, from Apophis or any object, we would certainly want to know these properties, such as the spin or the state of tumbling [of an asteroid]. “”

Nudging Apophis during the course will not be necessary because its orbital path has been so well calculated by astronomers, and there is also no risk that the spacecraft Ramses could accidentally put it on a dangerous orbit, explains Paolo Martino, project manager of the mission. The spacecraft has sensors that allowed it to avoid independently, and even if an impact occurred, its weak mass means that it would have little effect on Apophis, he says.

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