Nasa dart impact changed asteroid orbit around the sun, study finds

Saturday 07 - 07:00

By: Dakir Madiha

Nasa dart impact changed asteroid orbit around the sun, study finds

When NASA deliberately crashed a spacecraft into the asteroid moon Dimorphos in 2022, scientists quickly confirmed the collision shortened its orbit around its larger companion, Didymos. A new study now shows the impact also altered the path of the entire asteroid pair around the Sun, marking the first confirmed case of humans shifting an asteroid’s solar orbit.

The findings, published in the journal Science Advances, provide fresh evidence that kinetic impact missions could serve as a practical method for defending Earth against potentially hazardous asteroids.

Researchers found that the Double Asteroid Redirection Test, or DART, slightly slowed the binary system’s orbit around the Sun. The change measured about 11.7 micrometers per second, roughly 4.3 centimeters per hour. As a result, the solar orbit of Dimorphos and Didymos shrank by about 365 meters, shortening their 769 day journey around the Sun by approximately 0.15 seconds.

“This is the first time we have demonstrated that an asteroid has been moved into a different orbit by human intervention,” said Steven Chesley, a senior research scientist at NASA’s Jet Propulsion Laboratory. He noted that the results confirm the feasibility of redirecting asteroids through controlled impacts.

The research team, led by Rahil Makadia of the University of Illinois Urbana Champaign, analyzed 5,955 ground based radar measurements and 22 stellar occultation observations collected between October 2022 and March 2025. Stellar occultations occur when an asteroid briefly blocks light from a distant star. Many of the measurements came from amateur astronomers who tracked the asteroid system from multiple locations worldwide.

Scientists also determined that debris blasted from Dimorphos during the collision played a significant role in the orbital change. Some of the ejecta escaped the gravity of the asteroid pair, carrying momentum away and effectively doubling the deflection caused by the spacecraft impact alone.

“The asteroid receives a push in the opposite direction because of the ejecta recoil,” Chesley explained.

Although the shift in the asteroid system’s orbit is extremely small, researchers say it demonstrates the principle behind planetary defense strategies. A small nudge applied years in advance could be enough to steer a dangerous asteroid away from Earth.

Further confirmation may come later this year when the European Space Agency’s Hera spacecraft arrives at the Didymos system. Hera will map Dimorphos in high resolution and measure its mass, allowing scientists to refine calculations of how the collision altered the asteroid’s motion.

Researchers say each asteroid behaves differently, but the DART mission provides an important real world test of techniques designed to protect Earth from future asteroid threats.