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DART

  • Illustration of the DART mission. Credit: NASA/Johns Hopkins APL
  • DART impacting the smaller of the two Didymos asteroids, as seen from the larger body. Credits: ESA.

Asteroid impact risk

DART is the first kinetic impact mission dedicated to demonstrating the method of asteroid deflection in a Potentially Hazardous Asteroid. On Sept 22, 2022 DART spacecraft collided with asteroid Dimorphos, a 160 metres in diameter satellite of the four times larger asteroid Didymos. DART changed successfully the orbit of Dimorphos within the binary system, and its orbital period decreased in 33 minutes. Both asteroids in the Didymos system are presumably rubble-piles, bodies catastrophically disrupted by impacts and reaggregated. These rocky asteroids are composed of big blocks, called boulders, with sizes up to tens of metres that are embedded in fine-grained materials.


A new age of planetary defence

NASA's Double Asteroid Redirection Test (DART) spacecraft hurtled toward a binary asteroid while it was 11 million kilometres from Earth at a speed of 22.530 km/h. The spacecraft was equipped with a state-of-the-art imaging system that worked together with a state-of-the-art onboard set of targeting, guidance, navigation and control algorithms. The huge technological challenge of colliding with an asteroid at hypervelocity was achieved with success on September 22, 2022. All together, this NASA mission autonomously identified and distinguished between the two asteroids in its final moments, finally targeting the smaller body called Dimorphos, obtaining valuable science and finally crashing into it. As a consequence, DART impact shortened the orbital period of Dimorphos within the binary system in 33 minutes, a big success for the application of the kinetic impactor technique to planetary defence.

The success of the DART mission started a new age of planetary defence. This new area of planetary science is associated with the study of minor bodies: asteroids and comets. In a context of applied science, space exploration needs facts: we need to know the real physico-chemical properties of all the objects surrounding the Sun. Asteroids and comets have several properties that make them very different from planetary bodies. Then, planetary defence tries to develop our capabilities to study these bodies and to detect, and mitigate the risk from potential asteroid or comet impacts with Earth. In some sense, planetary defence can be considered "applied planetary science", a new discipline to address any future risk of impact by Near Earth Objects (NEOs).

Infographic showing the effect of DART's impact on the orbit of Dimorphos Credit: NASA/Johns Hopkins APL

ICE-CSIC's participation

As part of the DART Investigation Team, Dr. Josep M. Trigo-Rodríguez has promoted state-of-the-art experiments and techniques to infer the mechanical properties of the chondritic materials that form the Didymos system, used to evaluate the effectiveness of this mitigation approach. It is particularly relevant to know the contribution of the target properties and structure to the impact outcome: the Beta factor increases due to inelastic contribution from the material released in the impact plume as a consequence of the kinetic impact.

In addition, we share our know-how about the main processes affecting the reflectivity, and surface properties of chondritic asteroids. The surface of these undifferentiated bodies is exposed to what is known as space weathering. Solar wind reaches continuously asteroid surfaces, while small-scale collisions also excavate craters, contributing to heat locally the surface, and producing brecciated materials. Over time asteroid surfaces are fractured and mixed with implanted foreign materials. Then, all these processes change the reflectance properties and require careful study and interpretation. ICE-CSIC laboratory studies of the reflectance spectra of a diversity of chondritic meteorites is useful in the interpretation of DART observations.

 In addition, we have also contributed to the study of the evolution of the DART’s impact plume using ground-based modern telescopes. We participated in the photometric monitoring of DART’s impact effects. We are studying the dynamics of the particles released by DART impact, and infer their evolution into separate orbits, once detached from Dimorphos.

 

Senior institute member involved

Meet the senior researcher who leads our participation in the DART mission.

  • Josep M. Trigo-Rodríguez

    Josep M. Trigo-Rodríguez