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2021 The asteroid’s simulation ends in a crash

The artist's concept for the DART mission.

The artist’s concept for the DART mission.
Image: NASA

An international exercise to simulate an asteroid hitting Earth has ended. With only six days left before the fictitious impact, things don’t look good for a 185-mile-wide region between Prague and Munich.

Two years ago the organizers of this event accidentally destroyed New York is now the time for a border region crossing Germany, Austria and the Czech Republic to face the same fate. When I covered the first days of the simulation this week on Wednesday, the experts gathered were weighing their capabilities as a 460-foot-wide asteroid aimed at Central Europe.

This may sound like a grim role-playing game, but it’s a very serious business. Led by NASA’s Jet Propulsion Laboratory Center for the study of objects near the Earth, the asteroid impact simulation aims to prepare scientists, designers and key decision makers for the real thing if it ever happens. The table exercise began last Monday and takes place in practice at 7th IAA Planetary Defense Conference, organized by the United Nations Office for Outer Space Affairs with the assistance of ESA.

“Practice and training for different situations is an important part of preparedness, whether it’s done by medical professionals or sports teams or artists,” explained Andy Rivkin, a research astronomer at Johns Hopkins’ Laboratory for Applied Physics. “For planetary defense, this is our chance to bring together people with different experiences who often don’t have the chance to work together and look at different scenarios. This can help greatly in identifying important issues that we may not identify while working as small groups or individuals. “

Rivkin, who is attending the event, is co-chairing NASA’s double asteroid redirection test, which aims to Smash a spaceship into the asteroid Dimorphos at the end of 2022 (actually). By crashing into an asteroid, a kinetic impact element such as DART could “change the arrival time of the asteroid so that it does not arrive at the intersection at the same time as Earth,” Rivkin said, adding that his group was testing what was happening in detail. when you change the speed of an asteroid, ”in this case Dimorphos.

A distinctive feature of this year’s simulation is that the asteroid has come out of the sky, so to speak. Called the 2021 PDC, it was discovered just six months before its planned encounter with Earth. The chances of impact were initially estimated at 1 in 2,500, but on the first day of the simulation this increased to 1 in 100. By day 2, the chances were increased to a full 100%, with the site of impact being identified as in Central Europe.

For me, a key conclusion from this year’s simulation was the dramatic way in which key variables, such as the likely area of ​​impact and the affected population, were affected by new observations. At one point, for example, North Africa, the United Kingdom and much of Scandinavia were in the potential strike zone.

The participants in the simulation believe that it is impossible to apply mitigation efforts, such as a kinetic impact element or a nuclear bomb, given the short time – a consideration that has not been lost by planetary geologist Angela Stikl, another member of the DART team involved in the exercise.

“The diversion schedule is important,” Stikl, head of the DART Impact Modeling Task Force, said in an email. “Kinetic impact elements work best when they were made years earlier, so the little pressure you give has enough time to really change the incoming orbit away from Earth, so that we can even launch a spacecraft with kinetic hitting like a DART on the table exercise scenario, we may be late to really distract him from the course. ”

Previous desktop exercises provide many years of warning time, but not that. Accordingly, the focus of the exercises was on disaster response and the importance of pre-identification of dangerous asteroids.

For Andy Cheng, chief scientist and head of John Hopkins’ DART investigation team, the moment came when everyone learned that the fictitious asteroid was actually chipped past Earth seven years earlier, but was not discovered “because there is no earth – or space-based telescopic assets that would find it, “he explained in an email. If it was detected at that time, “there would be more than enough warning time to organize space missions to characterize it and mitigate the threat,” such as in a DART-like mission.

Accordingly, the mass simulation has become an exercise in predicting the possible damage that could be caused by the asteroid and where this damage could occur. This was not an easy task, given the many uncertainties about the offending object, such as its size and physical composition. Initial estimates put the asteroid between 35 meters and 2,300 feet (700 meters) long, followed by a more accurate estimate of 140 meters, which “significantly reduces the size of the worst case and the worst random impact energies,” according to the Day 3 report.

Updated map showing the endangered area in Central Europe.

Updated map showing the endangered area in Central Europe.
Image: NASA / JPL

Which brings us to the last day of the exercise (it turns out that this is a four-day project, not five days, as originally reported). Day 4 takes place on October 14, 2021 – just six days before the strike. With the impact now inevitablee the fake asteroid clear in the eyes, the terrible difficulty became clear.

The fictitious impact will occur on October 20, 2021 at 17:02:25 UTC, giving or taking one second. This level of precision is truly captivating and shows the high degree to which we would be prepared for that fateful moment, allowing people in the affected and surrounding areas to evacuate or hide.

Photographs taken by the Goldstone Observatory the day before limit the asteroid’s size to 105 meters. He wasn’t as big as he’d feared, but he was still big enough to cause serious damage. For Mallory DeCoster, a systems and mechanical engineer and member of the DART investigation team of John Hopkins, who is also involved in the exercise, the continuing uncertainty about the size of the asteroid has been worrying.

Map showing the different areas under threat according to the level of severity.

Map showing the different areas under threat according to the level of severity.
Image: NASA / JPL

“We know that one of the most critical pieces of information for decision makers is high-precision information about the size of the asteroid,” she said. “In the hypothetical impact scenario, we saw that the current capabilities of the instrument leave us with a fairly wide range of possible asteroid sizes, ranging from 30 m in diameter with a low threat to 700 m in diameter exploding on the continent. This showed how important it is to invest in instruments such as ground-based radars and space infrared sensors to provide high-resolution performance indicators. “

The false asteroid is expected to hit Earth at speeds of up to 9.5 miles per second (15 km / s), or 34,000 miles per hour (55,000 km / h). Zero Earth was supposed to live within 23 miles, but that number is expected to halve in the coming days as the asteroid approaches. The crash site was concentrated near the borders of three countries: Germany, the Czech Republic and Austria.

This area is predominantly rural and no estimates have been given for the size of the population affected. In the worst case scenario, the asteroid will cause damage extending 150 km in all directions. The threat map identifies the regions identified as incurable, critical, severe and serious. Prague, a city of 1.27 million people, is on the outer border of the serious zone, while Munich seems unable to do any harm.

If this situation were real, the International Asteroid Warning Network – a group that detects, tracks and characterizes potentially dangerous asteroids – would disseminate this information in accordance with a UN General Assembly resolution, according to today’s report. This should be done to “ensure that all countries … are aware of potential threats” and to emphasize the need to develop an effective emergency response and disaster management in the event of an impact on a site close to The earth “, according to resolution.

Stickle said several things stand out for this year’s exercise, including the importance of clear public communication, especially providing people with information about the threat and what can be done to prevent the Earth’s effects.

“I think DART can be a good addition to this as an example of how we prepare and test the necessary technology; the mission provides a good opportunity for public communication and engagement, ”Stickle writes. “The exercise also showed the importance of being able to deploy kinetic impact elements quickly in an emergency scenario.” However, she described the six-month schedule as “quite sporty” as they would have to act very quickly, even with a ready-made mitigation solution.

Mallory DeCoster, a systems and mechanical engineer and member of the DART investigation team, also intervened, saying that “we really need to find and track more asteroids”, adding that this is not surprising, “but this short warning scenario definitely emphasizes the importance from this.”

And that was the end of the round table, because there was really nothing left but to wait for the asteroid to hit. Everything is very painful, but this year’s simulation turned out to be useful. We hope that these exercises will continue to remain in the realm of science fiction.

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