NASA Invites the World to Watch the Double Asteroid Redirection Test (DART) Impact Event to Prevent Asteroid Collision with Earth at 6:14 AM on September 27 (Hanoi Time).
On August 23, NASA announced that the agency is preparing to crash a spacecraft into an asteroid as part of the world’s first mission to test technology for protecting Earth from potential asteroid or comet threats. They also invite the world to follow this unique event.
NASA’s DART spacecraft before colliding with the asteroid Dimorphos in the binary system. (Photo: NASA)
Viewers can watch the live broadcast of the DART spacecraft collision on NASA TV and the NASA website. The public can also view the event on NASA’s social media accounts, including Facebook, Twitter, and YouTube. Before the collision on September 27, NASA will hold a brief press conference from the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, where the DART spacecraft was designed and managed.
DART is the world’s first planetary defense test mission, conducting a deliberate impact on the asteroid Dimorphos to change its motion in space. Although the asteroid does not pose a threat to Earth, the DART mission will demonstrate that a spacecraft can autonomously navigate to collide with a relatively small target asteroid, and this technique is feasible for redirecting a celestial body that could potentially collide with Earth. DART is set to approach its target on September 26. “DART will provide crucial data that will help us better prepare if we detect an asteroid that poses a risk of colliding with Earth,” NASA stated.
According to NASA, the target of DART is the near-Earth binary asteroid system Didymos. This system includes the Didymos asteroid, which is 780 meters in diameter, and the smaller body Dimorphos, which is 162 meters in diameter. DART will collide with Dimorphos.
Using some of the world’s most powerful telescopes, the DART research team completed a 6-night observation campaign in August 2022 to confirm initial calculations about Dimorphos’s orbit around the larger parent asteroid Didymos, verifying the celestial body’s position for the impact. This is the world’s first effort to change the speed and trajectory of an asteroid moving through space, testing a redirection method that could be useful for Earth defense in the future.
“The measurements the research team conducted since early 2021 were crucial to ensure DART arrives at the right location and time for the impact with Dimorphos,” shared Andy Rivkin, co-lead of the DART research team at APL. “Confirming the measurement results through new observations shows that we do not need to change the trajectory and are getting close to the target.”
If DART successfully alters Dimorphos’s trajectory, this celestial body will move closer to Didymos, shortening its orbital period. However, scientists need to confirm that nothing else affects the asteroid’s orbit, including radiation from the asteroid’s surface that could push and alter its trajectory.
From late September to early October, around the time of the DART collision, Didymos and Dimorphos will come closest to Earth in recent years, at a distance of 10.8 million kilometers. Since March 2021, the Didymos binary system has been beyond the observational range of most ground-based telescopes due to its distance from Earth. However, in early July, the DART research team utilized powerful telescopes in Arizona and Chile—including the Lowell Discovery Telescope at the Lowell Observatory, the Magellan Telescope at the Las Campanas Observatory, and the Southern Astrophysical Research (SOAR) Telescope—to monitor the asteroid system and search for changes in its brightness. These changes occur when one of the two asteroids passes in front of the other, as Dimorphos’s orbit partially blocks the light they emit.
Studying the changes in brightness allows scientists to accurately determine how long it takes Dimorphos to orbit the larger asteroid, enabling them to predict Dimorphos’s position at various times, including the moment the DART spacecraft impacts. The results align with previous calculations. Through the latest observations, the research team can adjust their approach to determine whether DART successfully altered Dimorphos’s orbit after the collision and to what extent.
In October of this year, the research team will again use ground-based telescopes around the world to calculate Dimorphos’s new orbit. They hope that the smaller asteroid’s orbital period around Didymos will shift by a few minutes.
