Chinanews.com, Beijing, March 2 (Reporter Sun Zifa) Monitoring, evaluation and related research on the potential threat of asteroids and other extraterrestrial objects hitting the earth have attracted widespread attention from the academic community and the world in recent years.
The internationally renowned academic journal "Nature" recently published a group of five astronomy papers, focusing on the observations of the "Double Asteroid Redirection Test" (DART) mission carried out by NASA on a satellite of a near-Earth asteroid The research progress aims to reveal how the impact of the DART spacecraft changes the orbit of the impacted satellite, or how this method can be used to create a defense system to prevent the potential impact of the celestial body with the Earth.
According to reports, in late September 2022, the DART mission crashed a spacecraft into the satellite Dimorphos of the near-Earth asteroid (65803) Didymos. To test the feasibility of the potential method of asteroid deflection in order to change the orbit of the "twin".
Five new papers published in Nature estimate the change in momentum of the twin and describe how momentum is transferred from the spacecraft to the twin:
The first study determined the change in the orbital period of the smaller twin around the larger twin following the DART impact, with two independent methods of measuring the change showing a shortening of its orbital period by about 33 minutes.
The second paper reconstructs the DART spacecraft's impact on the twin, which could help plan future missions and hopefully improve the certainty of outcome predictions.
The researchers also described the location and nature of the impact point, noting that the impact point was between two rocks, one of which was grazed by the spacecraft as it collided with the twin.
A third paper reports Hubble Space Telescope observations of plumes (debris created by the impact) whose velocity and evolution may explain the change in momentum caused by the impact.
The fourth paper studies that the orbital speed of the "twin star" slowed down after the impact.
The researchers believe that the momentum transferred from the spacecraft to the twin was enhanced by the recoil of the ejecta vapor from the impact.
The fifth paper is based on the observation data of the "twin star" before, during and after the impact of the global citizen scientific telescope network (including 3 telescopes on Reunion Island that captured the moment of impact and 1 telescope in Nairobi, Kenya), The researchers estimated the mass and energy of the ejected dust, as well as its evolution over time, which may help to understand the final outcome of the impact mission.
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