"Humans Luckier Than Dinosaurs"...Asteroid Impact and Trajectory Change Success [Reading Science]

US NASA Announces Success of 'DART' Results on 11th
Small Spacecraft Collided with Asteroid on 26th Last Month
Study Attempts to Change Earth-Threatening Asteroid's Path via Physical Impact
Orbit Period Shortened by 32 Minutes, More Than Expected

[Asia Economy Reporter Kim Bong-su] "Humanity was luckier than the dinosaurs." This is the assessment of an American scientist regarding the successful completion of the world's first planetary defense experiment. It has been practically proven that if an asteroid, identified as a cause of Earth's mass extinction including the dinosaurs, approaches, its trajectory can be altered by colliding a spacecraft with it.

The U.S. National Aeronautics and Space Administration (NASA) held a press conference on the afternoon of the 11th (Eastern Time) and announced that in the Double Asteroid Redirection Test (DART) conducted on the 26th of last month, the orbit of the asteroid Dimorphos, which was struck by the DART spacecraft, changed, shortening its orbital period around its parent asteroid Didymos by 32 minutes. Originally, Dimorphos had an orbital period of 11 hours and 55 minutes, but after the DART spacecraft collision, it was reduced to 11 hours and 23 minutes.

This change was much greater than NASA had initially predicted. NASA collided the 570 kg DART spacecraft with Dimorphos, which is about 160 meters in diameter, at a speed of 6.2 km/s, or 22,530 km/h, and had predicted that the orbital period would shorten by at least 73 seconds to about 10 minutes. The actual effect was more than about 25 times greater than expected.

NASA explained that the collision of the DART spacecraft generated many fragments and dust, which may have pushed Dimorphos away from Didymos like the thrust generated on the opposite side when a balloon is punctured.

Bill Nelson, NASA Administrator, said, "This is a pivotal moment for all humanity and planetary defense," adding, "This experiment showed that we are making efforts to prepare for any threats that may arise in space."

This project was jointly conducted by the United States and European countries. The U.S. spent $314 million to build and launch the DART spacecraft. The Italian Space Agency (ISA) produced the small observation satellite LICIACube, which accompanied the mission, and the European Space Agency (ESA) plans to launch the Hera spacecraft after 2026 to conduct detailed follow-up observations.

The DART spacecraft was launched last November aboard a Falcon 9 rocket and traveled approximately 11 million kilometers over about 10 months to conduct this collision experiment near Jupiter. This planetary defense experiment was designed to prepare for an asteroid impact scenario similar to the one that ended the dinosaur era about 66 million years ago. The key point was whether the orbit of an asteroid approaching Earth could be altered by physically colliding a spacecraft with it. NASA expects no threat to Earth from this experiment. Although Didymos and Dimorphos are classified as Near-Earth Objects (NEOs) that approach within 48 million kilometers of Earth, NASA's analysis suggests that aside from a slight shortening of Didymos's solar orbital period, there will be no significant changes. Based on the results of this experiment, NASA plans to improve computer models developed through laboratory collision experiments and establish strategies to defend Earth from asteroids on collision courses with our planet.