They artificially alter the movement of the asteroid

For the first time, mankind was able to change the motion of a celestial body in space with a space probe used as a projectile.

Analysis of data obtained by NASA’s DART mission research team over the past two weeks shows that the deliberate impact of the DART spacecraft on its target asteroid, Dimorphos, has successfully altered the asteroid’s orbit. This experiment is the first large-scale demonstration of this asteroid deflection technology.

The benefit of this technology is to protect the Earth from the impact of asteroids, diverting the paths of all those who have a collision course with our planet or who will come dangerously close.

Before the DART collision, Demorphos took 11 hours and 55 minutes to orbit the larger asteroid, Didymus. Since DART’s collision with Dimorphos on September 26, astronomers have used ground-based telescopes to measure how much time has been spent making a complete revolution around Didymos. Now, the research team has confirmed that the spacecraft’s impact changed Demorphos’ orbit around Didymus by 32 minutes, shortening the orbit from 11 hours 55 minutes to 11 hours 23 minutes. This measurement has a margin of error of about two minutes.

Prior to the collision, NASA defined the minimum successful change in Demorphos’ orbital period as a change of 73 seconds or more. These early data show that DART exceeded this lower limit of the norm by more than 25 times.

“This finding is an important step in understanding the full impact of DART’s impact on its target asteroid,” explained Laurie Glaese, director of NASA’s Planetary Science Division. “With new data coming in daily, astronomers will be able to better assess whether a mission like DART could be used in the future to help protect Earth from an asteroid collision, if one day we find it, and how can we do it?”

This image, taken by NASA’s Hubble Space Telescope on October 8, 2022, shows debris dislodged from the surface of Demorphos 285 hours after the DART impact on September 26. The shape of the rest of the awakening has changed over time. This substance and how it moves in space is still being studied. (Image: NASA/ESA/STScI/Hubble)

The research team still gets data from ground-based observatories around the world, as well as from radar facilities such as NASA’s Jet Propulsion Laboratory (JPL) in Goldstone, California, and the Green Bank Observatory at the US National Science Foundation in West Virginia. Scientists update the period measurement with frequent observations to improve its accuracy.

The “ejection” of many tons of rock from the asteroid, which was displaced and thrown into space due to the collision, is also currently being analyzed. The recoil from this debris explosion significantly boosted the DART’s thrust against the Dimorphos, just like the way the air coming out of a balloon sends the balloon in the opposite direction.

To fully understand the effect of ejection rebounds, more information is needed about the physical properties of the asteroid, such as its surface features and how strong or weak it is. These issues are still under investigation.

For the analyses, the astronomers will continue to study images of Dimorphos obtained by DART itself moments before the collision, and images obtained by the Italian CubeSat LICIACube, provided by the Italian Space Agency and which traveled with DART until it separated on its arrival. . Near the binary asteroid system. It is expected that the analysis of all these images will assist in obtaining a reasonably accurate estimate of the mass and shape of the asteroid.

In about four years, the European Space Agency’s Hera project will conduct detailed studies of both Dimorphos and Didymos, paying particular attention to the crater left by the DART collision and making more precise measurements of Dimorphos’ mass.

Both Dimorphos and Didymos pose no danger to Earth, before or after DART’s collision with Dimorphos. (Source: NASA)