Comets! We are not ready for the catastrophic threat

Comets! We are not ready for the catastrophic threat

As a rule, information about asteroids flashes in the headlines, but comets also carry a clear danger.

If you are afraid of only asteroids, then it's time to expand your consciousness. Comets can also cause natural disasters on Earth and politicians should take measures to counter the threat. So says Joseph Nuth, a research fellow at NASA's Goddard Space Flight Center in Greenbelt, MD.

“People interested in protecting the planet simply ignore this danger,” Nuth said during a press conference on Monday (December 12) at the annual autumn session of the American Geographical Union (AGU).

The main reason for the lack of attention lies in the difficulties associated with detecting and tracking ice bodies. But we can do something.

Dangerous comets

Asteroid focusing is understandable. After all, they are much more in near-Earth space and, therefore, they represent the main impact force.

Near-Earth asteroids (OZA) are easier to find and track, because their orbits are close to Earth. But comets most of their life are located in the dark depths of the outer part of the Solar System, which prevents astronomers from detecting them before they pass nearby. (For example, the famous Halley's comet flies around the Sun every 75 years).

“Their appearance is unpredictable,” said Nuth during a scientific talk before the meeting.

As an example, he cited C / 2013 A1 (McNota) 0.3 miles wide (0.5 km), opened in January 2013. After 22 months in October 2014, she was already buzzing over Mars, having traveled within 87,000 miles (140,000 km) near the Red Planet. Therefore, there is an element of surprise. And this affects the preparation of the launch of the device, which would change the cometary course or destroy.

“If you study the schedule of building high-reliability space mechanisms, you will realize that it takes 5 years,” said Nut.

There are other problems. For example, a typical comet is larger than the average AOR, and cuts into the surface with a higher relative velocity due to an elliptical orbit (favorable for direct impacts). At OZA it is 44700 miles per hour (71940 km / h), and the comet flies twice as fast. If you recall the case of Mars, then the C / 2013 A1 was driving 125,000 miles per hour (200,000 km / h).

And although cometary strikes are rare, they will cause much more damage. That's why you need to sound the alarm.

What to do?

Nuth believes that the world must prepare for a strike now or in the near future. Because, postponing until the last minute, we deprive ourselves of the possibility of protection.

“It’s important to reduce the response time,” he says, referring to the five-year delay between mission approval and launch.

His plan is to build two spacecraft (an observer and an interceptor), which will be inactive until needed. If an uninvited guest arrives, the first one will go on reconnaissance and help find out the orbital path and assess the threat. If it is serious, then the second will perform its task.

The interceptor will be able to install a nuclear bomb (required for very large objects). This plan works not only for comets, but also for asteroids, slipped past the attention of astronomers.

To implement the project, NASA will have to make a request to Congress.

“This is a significant amount,” said Nut. “Probably several hundred million dollars for one machine.”

“I’m a NASA scientist,” he added. - “I do not take part in politics. Do not even belong to the administration. Therefore, I reason only as a researcher. ”

How about a laser?

This is also a way out. For example, powerful laser explosions could evaporate the surface of a dangerous comet from afar, causing an eruption of jets that would bring down the original trajectory.

“These effects were observed with solar heating,” said lead author Kwicheng Zhang, a student physicist at the University of Santa Barbara.

He created a computer model of exactly the same lasers that I plan to build for the Starshot project, aimed at the explosion of Alpha Centauri nano-probes at the level of 20% of the speed of light.

“A large enough laser array will cope with any comet,” he and his team say in the study.

Zhang added that the array could also theoretically solve the problem of space debris and perform many other tasks.

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