Planetary SecurityFirst Planetary Defense Test

Published 28 November 2021

An asteroid slammed into Earth 63 billion years ago, igniting vast fires which threw smoke and soot into the atmosphere, plunging the planet into a prolonged winter, killing many plants on which herbivores depended. The extinction of the dinosaurs was only one consequence of that event. NASA wants to make sure there is no repetition of such a calamity: The agency is planning the first-ever planetary defense test, which deliberately collides a spacecraft into an asteroid called Dimorphos. The aim is to try and deflect the asteroid away from its Earth-bound trajectory. 

Lawrence Livermore National Laboratory (LLNL) is taking part in NASA’s first-ever planetary defense test, which deliberately collides a spacecraft into an asteroid called Dimorphos.

The Double Asteroid Redirect Test (DART) will examine technologies that will prevent an impact of Earth by a hazardous asteroid. DART is the first demonstration of the kinetic impactor technique to change the motion of an asteroid in space. The asteroid is a small moon of a larger asteroid called Didymos. The impact into Dimorphos does not pose any danger to Earth.

LLNL’s role as participants in the DART mission include a working group focused on modeling the impact and deflection of the asteroid.

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Megan Bruck Syal, who leads LLNL’s Planetary Defense group, said she looks forward to the experiment and is excited to assist NASA and the Lab’s mission partners to use this experiment to help advance the science of planetary defense.

“Our team has been supporting DART with impact simulations and analysis since 2015, and it is an incredible feeling to be on the precipice of its launch,” Bruck Syal said. “DART is an essential first test of kinetic impact deflection effectiveness and will inform how we model asteroid response to a variety of mitigation techniques in the future. Many students, postdocs and staff at LLNL have contributed to our preparedness for this experiment; it is a true interdisciplinary team effort.”

Katie Kumamoto, a LLNL geoscientist and a member of the LLNL impact modeling team, said DART is a groundbreaking mission and a big step toward practical asteroid preparedness.

“We don’t have a lot of data on the properties of asteroids, like their strength or density, but these properties can have a large effect on the magnitude of the deflection we would get from a kinetic impact,” she said. “DART is thus a two-fold opportunity, to both demonstrate that we can actually deflect an asteroid in space and get us more data on the properties of asteroids, which will help us prepare for potential future impacts.”

Team member Cody Raskin has helped develop simulation tools and methods for the inverse problem of determining the asteroid’s material properties by measuring its response to the impact of the DART spacecraft. This includes adapting machine learning techniques to characterizing the mapping that connects asteroid material properties to the change in momentum imparted by the impact.

“One of the major unanswered questions in the field of planetary defense is just what these near-Earth asteroids are