Tag Archives: deflection

NASA’s Asteroid Deflection Experiment Yields Surprising and Mysterious Outcomes

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The NASA DART probe, depicted on the upper right, is on a trajectory to collide with the asteroid Dimorphos, shown on the left.

Steve Gribben/Johns Hopkins APL/NASA/AP/ALAMY

Following the collision of NASA’s spacecraft with an asteroid, its orbit is expected to change gradually next month, leaving astronomers puzzled.

In 2022, the Double Asteroid Redirect Test (DART) sent a nearly 600-kilometer spacecraft towards a small asteroid known as Dimorphos.

Prior to the collision, Dimorphos completed an orbit every 11 hours and 55 minutes. Observations soon indicated that the impact shortened this orbital period by approximately 30 minutes, although in the following weeks and months, the orbital period diminished by an additional 30 seconds.

Astronomers have proposed that this phenomenon might be due to the release of small debris during the impact, which could gradually cause energy loss and result in a reduced orbital path.

Recently, Harrison Agrusa and Camille Chattanette from the University of Côte d’Azur in Nice, France, asserted that debris ejection cannot solely explain the observations.

“The boulders can be flung by Dimorphos, leading to a wider dispersion. This momentum will eventually revert and be transferred back to Dimorphos,” Agrusa explains.

Agrusa theorizes that a more plausible reason for Dimorphos’ shifting trajectory is that its impact affects its rotation in a complex manner, causing rocks on its surface to shift. The friction generated by these rocks could lead to heat production from their collisions. The resultant energy loss as heat might clarify the decrease in the asteroid’s orbital path, although this study has not modeled that aspect.

“When you rearrange materials on a surface, you’re altering the gravitational potential energy of Dimorphos itself,” Agrusa states. “This adjustment could feasibly slow down the orbital period within a month, as this would be a prolonged process.”

This highlights the challenges in predicting how asteroid orbits will alter post-impact, yet according to Agrusa, this phenomenon is less concerning when deflecting an asteroid heading towards Earth. This is because binary asteroid systems like Didymos and Dimorphos are quite uncommon, making it unlikely that similar effects will occur for a solitary asteroid orbiting the Sun.

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Source: www.newscientist.com

National Laboratory Simulates Core Deflection of Armageddon-Type Asteroid

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Last year’s successful double asteroid redirection experiment, which involved firing a satellite bomb into an asteroid, has been followed by a detailed simulation of a nuclear deflection scenario, similar to the plot of the 1998 space disaster movie Armageddon.

Researchers at Lawrence Livermore National Laboratory, led by Mary Varkey, have published a paper advancing the active field of research on planetary defense against asteroid threats. They propose that detonating a nuclear explosive device as close as possible to an incoming asteroid may be the best strategy, considering that using satellites as missiles is not always practical.

The challenge, however, lies in precisely deflecting the asteroid’s nucleus to avoid potential impact with Earth, as depicted in the movie Armageddon, or the widespread destruction scenario depicted in the film Deep Impact.

In their paper published in the Planetary Science Journal, Burkey et al. explain the complexities involved in simulating the energy storage and the interaction of X-rays from a nuclear explosion with the asteroid’s surface, emphasizing the high computational cost and the need to break down the problem into stages for accurate modeling.

The team’s efforts have resulted in a comprehensive simulation of the nuclear deflection scenario, offering insight into the potential outcomes of such an event. The team also highlights the need for faster simulations, potentially utilizing machine learning to optimize response times for specific threats.

Image credits: Varkey et al.

By simulating the nuclear deflection scenario, the team aims to further advance the understanding of potential strategies for planetary defense against asteroid threats and minimize response times for future events.

Source: techcrunch.com