▲ Appearance of 37 rocks floating around in space in the aftermath of an experiment in which a spacecraft intentionally crashed into an asteroid. Photo = NASA, ESA, David Jewitt (UCLA); Alyssa Pagan (STScI)
On September 27, 2022, a movie-like experiment of intentionally crashing a spacecraft into an asteroid for the first time in human history was successfully conducted. At the time, the U.S. National Aeronautics and Space Administration (NASA) intentionally collided the DART spacecraft with Dimorphos, a satellite of the asteroid Didymos, located 11 million km away from Earth. On this day, the DART spacecraft flew at 6.1 km per second and met its fate when it collided with its target, Dimorphos.
In the aftermath of the collision, Dimorphos dust and debris formed, and a comet-like tail formed behind the asteroid. NASA analyzed that more than 1,000 tons of dust and rocks were scattered in space due to the spacecraft’s collision with Dimorphos. In particular, during this process, the rocks on the asteroid fell off and started floating around in outer space. The number confirmed by the Hubble Space Telescope was 37, with a diameter of 4 to 7 meters.
▲ The DART spacecraft just before it collided with the asteroid.
So what happened to these rocks that fell into outer space afterwards? Recently, European Space Agency (ESA) astronomer Marco Fenucci and Italira National Institute for Astrophysics Albino Carbonnani published interesting research results on this. The path of these rocks was predicted through computer simulation analysis. As a result, it was determined that there was no possibility of all the rocks flying toward the Earth and impacting it.
However, the research team discovered that the orbits of these rocks intersect with Mars’ orbit in the long term. In particular, four of these rocks are predicted to come close enough to collide with Mars, with two predicted to occur in 6,000 years and the other two to occur in 15,000 years. As a result, the four rocks could have fallen on Mars by mistake, not by human error. In particular, even the smallest rock can be a huge blow to Mars. Mars has a thin atmosphere and is not nearly as protected from celestial bodies as Earth. According to the research team, if this single rock falls vertically, a crater of up to 300 meters could be created on Mars.
▲ The asteroid collision process of the DART spacecraft captured by the Hubble Space Telescope
Regarding this, the research team said, “Based on all observations made so far, it was confirmed to be a successful experiment because the Dart spacecraft collided with Dimorphus and changed its orbital period and did not affect the Earth. However, it was confirmed that the experiment was successful because the material that fell from the asteroid did not affect the surrounding celestial bodies.” “This study suggests that a more cautious approach is needed in future missions because this could have an impact,” he said.
Meanwhile, the reason the DART spacecraft collided with Dimorphos was to test whether the orbit could be changed by colliding with an asteroid that could threaten Earth in the future. It was a grand experiment to change the orbit of an asteroid that could threaten Earth in the future, and the mission ended successfully, with Dimorphos’ orbital period actually changed by about 33 minutes. DART (Double Asteroid Redirection Test) is a small spacecraft weighing about 500 kg that does not carry explosives and was launched on November 24, 2021. Dimorphos, which became the test site for the DART spacecraft, is a small asteroid with a diameter of 160 m, but if it collides with the Earth, it can have the destructive power of a large nuclear weapon.
Reporter Park Jong-ik
