The scientists National Aeronautics and Space Administration (NASA)NASA’s DART asteroid impact mission aims to paint a more detailed picture of its asteroid targets, Didymos and Dimorphos, a study that could help better understand the formation and evolution of such binary asteroids.
dirtstands for “Double Asteroid Deflection Test,” and it only impacted the smaller object in the double asteroid system, the moon. Dimorphousorbiting a larger space rock DidymusStill, the goal was to see how such a collision would affect both objects, and the data collected from this successful mission may help scientists plan better. Planetary Defense Missions Divert an asteroid that could collide with Earth.
DART was able to take images of the two moons before colliding with Dimorphos on September 26, 2023. Near-Earth AsteroidsItalian asteroid observation cubesat (LICIA Cube) Through the mission, researchers were able to identify some of the geological and physical characteristics of Didymos and Dimorphos.
A research team led by Olivier Barnouin of the Johns Hopkins University Applied Physics Laboratory studied the surface of Didymos, the larger of the two asteroids. The researchers found that at high altitudes, Didymos is rough, with large boulders ranging from 33 to 525 feet (10 to 160 meters) in length, and several craters. At lower altitudes, the asteroid’s surface is smoother, with fewer large boulders and craters.
small Ozuki The companion star, Dimorphos, has a wider range of rocks on its surface, and while it has few craters, it does have some cracks, or “faults,” running through it.
This discovery led Barnuan and his colleagues to conclude that Dimorphos probably formed from material blown off Didymos, which then clumped together under the influence of gravity.
The team estimated the ages of the two asteroids based on the number of craters they have, and found that the parent body, Didymos, is 12.5 million years old, making it 40 to 130 times older than Dimorphos, while the moon is estimated to be about 300,000 years old.
Related: NASA’s asteroid impact DART mission completely changes target geometry
Another team of scientists, led by Maurizio Pajola of the INAF Astronomical Observatory in Padua, looked at the size and distribution of the rocks across Dimorphos and concluded that they were not formed all at once, but at different times.
This means that the surface rocks of Dimorphos are a direct descendant of Didymos. Binary asteroids These objects form from material ejected from larger partners, a process that may also explain the distinctive ridge at the equator of the parent body, Didymos.
Another team, led by Naomi Murdoch of the University of Toulouse, looked at rock tracks left on Didymos’s surface, and found that it is made up of a very loose material that could support much less weight than dry sand on Earth or lunar soil.
Meanwhile, Alice Luchetti of the INAF Observatory in Padua and her colleagues found that the rocks on Dimorphos’ surface have been breaking down over about 100,000 years through a process called “thermal fatigue,” in which temperature changes cause microscopic cracks to form in the rocks.
100,000 years may seem an incredibly long time to us, but geologically, it is a very long time, especially The solar system is about 4.6 billion years old. This means that the heat exhaustion experienced by Dimorphos is rapid. Rocky asteroids It is composed of silicate material and nickel-iron.
A third team, led by University of Toulouse researcher Colas Robin, compared 34 rocks measuring between 5.5 feet (1.67 meters) and 22 feet (6.7 meters) across on Dimorphos’ surface with rocks found on loose “rubble pile” asteroids. Itokawa, Ryuguand Bennu.
They found similarities in the rock morphology of all these asteroids, suggesting to Robin and his colleagues a common mechanism for their formation and evolution.
The team’s findings build a detailed picture of the Didymos system before DART collided with Dimorphos. Hera Mission From the European Space Agency (ESA).
Hera, scheduled to launch this October, will encounter Didymos and Dimorphos in September 2026. Launching into the Didymos binary star system, Hera will capture high-resolution data that will allow a more comprehensive study of the system after the DART collision. This will allow scientists to: Aftermath of the DART collision With Dimorphos.
Three teams the study paper was Published Tuesday (July 30th) Journal Nature.
