Based on how an asteroid's spin alters during a near approach with Earth, astronomers have discovered a mechanism to detect the internal structure of asteroids.
With DART, the Double Asteroid Redirection Test, NASA successfully flew a spacecraft directly at the centre of a close asteroid in late September. The stadium-sized space rock was struck by the one-way kamikaze mission, which successfully reset the asteroid's orbit. DART was the first attempt at a planetary defence system, showing that experts might be able to divert an asteroid that was headed for Earth.
MIT scientists now have a device that could help future asteroid-targeting missions be more effective. Based on how an asteroid's rotation alters during near encounters with larger bodies like the Earth, the team has created a method to map the internal structure, or density distribution.
Scientists could devise the most effective defence by understanding how the density is dispersed inside an asteroid. In contrast to deflecting an asteroid with a denser, less balanced interior, a DART-like spacecraft could be aimed differently if the interior of the object were relatively light and uniform.
The novel method of mapping asteroids was created by Jack Dinsmore '22, a physics major at MIT who argues that if you knew the density distribution of the asteroid, you may hit it at just the correct point to make it go away.
The team is keen to use the technique on Apophis, a near-Earth asteroid that is thought to provide a serious threat should it make contact. For at least a century, experts have discounted the possibility of a collision during Apophis' upcoming flybys. Beyond that, their predictions become hazy.
According to Dinsmore, a PHD student at Stanford University, "Apophis will skip Earth in 2029, and scientists have cleaned it for its upcoming encounters, but we can't clear it forever." Therefore, it is beneficial to comprehend this asteroid's characteristics because it will be crucial to know its composition if we ever need to reroute it.
In a report that is published today in the Monthly Notices of the Royal Astronomical Society, Dinsmore and Julien de Wit, assistant professor in MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS), describe their innovative methodology.
Contrasting raw versus cooked
Dinsmore's participation in a de Wit-taught MIT course last year served as the inspiration for the team's asteroid-mapping technique. The course 12.401 (Essentials of Planetary Sciences) presents the fundamental concepts and processes that govern the formation of planets, asteroids, and other solar system bodies. Dinsmore studied the behaviour of an asteroid during a near contact for his capstone project.
He created a piece of computer code in class to model different asteroid sizes and forms as well as how their orbital and spin dynamics alter in response to the gravitational attraction of a larger object, such as the Earth.
"At first, I only sought to inquire as to what occurs when an asteroid passes by Earth. Does it even react? Because I wasn't sure," recalls Dinsmore. "And the answer is that it does, but in a way that heavily depends on the shape and physical characteristics of the asteroid," she continued.
That first insight sparked a further inquiry: Could the physics of an asteroid's close approach be utilised to forecast not only its form and size but also its internal composition? Through the MIT Undergraduate Research Opportunities Program (UROP), which allows students to do original research with a faculty member, Dinsmore continued the experiment with de Wit to find a solution.
He and de Wit investigated the dynamics of a close contact in further detail, using a more intricate computer programme that they used to model a variety of asteroids, each with a unique size, shape, interior composition, or density distribution. They then carried out the simulation in the future to see how each asteroid's spin should fluctuate or change as it approaches close to a gravitationally-pulling object of a given mass.
De Wit says, "It's like how you can detect the difference between a raw and boiled egg." "The egg responds and spins differently when you spin it, depending on the characteristics of its interior. The same is true of an asteroid during a close encounter: By seeing how it reacts to the intense gravitational forces it encounters during a flyby, you can gain an understanding of what is happening on the inside.
A close contest
The group is presenting their findings in a brand-new software "toolkit" called AIME, which stands for Asteroid Interior Mapping from Encounters and also means "love" in French. From observations of an asteroid's spin change during space travel, the software can be used to recreate the interior density distribution of an asteroids a close encounter.
Comments
Post a Comment