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NASA’s DART Mission: Paving the Way for Meteor Observations
In a landmark achievement, NASA’s DART spacecraft collied with the Dimorphos asteroid in 2022, effecting a measurable change in its orbital path around the larger Didymos asteroid. This event not only marked a significant moment in planetary defense but also launched debris into space, which new research suggests could eventually reach both Mars and Earth.
The newly published modeling, now available on the preprint server arXiv and set to appear in the upcoming September issue of The Planetary Science Journal, explores how tiny meteoroids from this debris could become observable from our planet in the future, albeit in a harmless way.
On September 26, 2022, the DART spacecraft, weighing about half a ton, impacted Dimorphos at a velocity of approximately 6.1 kilometers per second. This impact succeeded in reducing Dimorphos’ orbit around Didymos by over half an hour, forming part of a global effort towards planetary defense.
In October, the European Space Agency’s Hera mission will launch to conduct a detailed examination of Dimorphos. This investigation aims to collect vital information regarding the asteroid’s mass, structure, and composition, helping establish the kinetic impact method as a reliable planetary defense technique.
As co-author and ESA Hera mission scientist Michael Kueppers notes, the DART impact provides a unique opportunity to study how debris reaches other celestial bodies. The meticulous observations from both the LICIACube—a spacecraft deployed from DART—and ground-based observers allow scientists to simulate the movement of ejecta with remarkable accuracy.
Eloy Peña-Asensio, the lead author from the Department of Aerospace Science and Technology, Politecnico di Milano, shares insights on their findings: “We identified potential trajectories for ejecta particles that could result in meteor events on both Mars and Earth.” Their simulations suggest that material ejected at around 450 meters per second could reach Mars within 13 years, while faster ejecta at 770 m/s could arrive in just seven years. Particles exceeding 1.5 km/s may cross into the Earth-Moon system on a similar timeline.
Peña-Asensio highlights the implications of these findings: “Future meteor observation campaigns will be vital to confirm whether ejecta from the Dimorphos impact will touch down on our planet, leading us to potentially experience the first human-made meteor shower.”
The path that these meteoroids will take—towards Earth or Mars—will hinge on their location within the DART’s impact plume. Material expelled to the north of this plume may be more inclined to travel towards Mars, while debris from the southwest position is more likely to head towards Earth. Notably, even the largest particles produced by this event would only be as big as a softball and would likely disintegrate within Earth’s atmosphere, although they might survive passage through Mars’ thinner atmosphere.
Currently, it seems that only smaller particles would be propelled towards Earth, as these are the fragments expected to be launched with the greatest velocities. The potential for these particles to create observable meteors remains uncertain, underscoring the importance of ongoing night sky observations.
Michael Kueppers further notes, “The precise data we have regarding the impact site and the properties of the impactor—as well as the observations of the ejecta—have allowed us to predict the long-term behavior of this material.” The data from Hera’s future investigation promises a comprehensive look into the source of these meteoroids, enriching our understanding of celestial mechanics.
With over 1,000 known meteoroid streams orbiting the Earth, associated with renowned meteor showers like the Perseids and Taurids, scientists are adept at tracing the origins of meteors. This current study employs a reverse approach to predict the characteristics and timings of meteors resulting from the DART impact.
“Identifying and observing meteors related to the DART impact could be exhilarating, potentially revealing their chemical compositions through their brightness and color,” Kueppers explains. The distinctive orbital patterns of these meteors would allow them to be differentiated from others, likely revealing slow-moving meteors primarily visible from the southern hemisphere, especially in May.
Hera has been transported across the Atlantic from Europe to Cape Canaveral, set for launch aboard a SpaceX Falcon 9 rocket this October. The spacecraft is expected to reach Dimorphos and initiate its scientific mission by late 2026.
As humanity takes steps to harness our understanding of planetary defense, the implications of this research stretch far beyond one mission, paving the way for future exploration and potentially transformative astronomical events.
Source
www.esa.int