Study: NASA Space Strike Might Have Reshaped an Asteroid

2024 · VOA Learning English

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Transcript

1. A new study suggests that an asteroid strike by an American spacecraft likely changed the shape of the targeted object.

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2. NASA crashed the DART spacecraft into the asteroid Dimorphos in 2022.

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3. The asteroid strike happened about 11 million kilometers from Earth.

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4. The experiment tested a method for changing the orbit of some asteroids to prevent them from possibly crashing into our planet in the future.

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5. NASA has said its studies of the crash showed it was successful because the force of the strike changed the asteroid’s orbit around a larger

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6. asteroid Didymos. NASA’s measurements also found the strike reduced the orbital period of Dimorphos by 33 minutes.

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7. Such a major crash would normally create a large crater in the targeted object.

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8. But a new study presents evidence that the crash made more than a hole it likely changed the shape of the whole asteroid.

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9. Astronomers at the University of Bern, in Switzerland carried out the research. A study detailing the findings recently appeared in the publication Nature Astronomy

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10. The team used a computer simulation system to study the changes to Dimorphos that resulted from the crash.

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11. The system aimed to recreate the breakup of space objects that have been hit.

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12. The researchers said their simulation method has been used in the past to recreate space objects crashing into each other.

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13. For example, the team said it confirmed the results of a Japanese spacecraft collecting a sample from the Ryugu asteroid in 2019.

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14. Sabina Raducan is with the Physics Institute of the University of Bern. She helped lead the project.

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15. Raducan described the simulation process in a statement as “computationally intensive.”

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16. In total, she said 250 simulations were completed, which reproduced the first two hours after the asteroid strike.

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17. The researchers used all available information about NASA’s operation.

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18. These included the predicted shape of Dimorphos, data on the strike itself, as well as the size of the cloud the crash left behind.

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19. In addition, the team aimed to estimate unknown details about the asteroid and the surrounding area.

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20. “Then what we did is check which of the simulation run outcomes most closely match observed reality,” Raducan said.

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21. She added that results of the research provided clear evidence that the crash turned Dimorphos into a relatively weak rubble pile asteroid.

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22. Raducan explained this meant that the object is currently being held together “by the asteroid’s extremely weak gravity” rather than a solid and strong mass.

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23. The researchers noted that the results of the simulation and the team’s examinations partly explain why the crash was so effective in changing the path of the

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24. Raducan said the results also persuaded the team that “the likelihood is that the crater grew to encompass the entire body itself, so that Dimorphos ended up

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25. being completely reshaped.” It is therefore unlikely that a crater still exists after the crash.

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26. The researchers said the existence of a crater can be investigated further by a European Space Agency (ESA) spacecraft.

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27. The spacecraft, called Hera, is preparing for a possible launch in October.

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28. ESA says Hera’s cameras and instruments will carry out detailed studies of Dimorphos and the asteroid it orbits, Didymos.

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29. During the operation, the spacecraft will aim to collect the most data yet on such an asteroid system. I’m Bryan Lynn.

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