Protecting Earth from asteroid impact with a tethered diversion

Date:
June 18, 2020
Source:
Springer
Summary:
The use of a tether assisted system could prevent an asteroid
impacting Earth without the risk of fragmentation.



FULL STORY ==========================================================================
Our planet exists within the vicinity of thousands of Near-Earth Objects (NEOs), some of which -- Potentially Hazardous Asteroids (PHAs) -- carry
the risk of impacting Earth causing major damage to infrastructure and
loss of life. Methods to mitigate such a collision are highly desirable. A
new paper published in EPJ Special Topics, authored by Flaviane Venditti, Planetary Radar Department, Arecibo Observatory, University of Central
Florida, Arecibo, suggests the use of a tether assisted system to prevent
PHA impact.


==========================================================================
The method suggested by Venditti and her colleagues involves using the
tether - - previously suggested for other uses, such as space/lunar
elevators and tethered satellite system -- to connect the threatening
PHA to another, smaller, asteroid, thus changing the centre of mass of
the two and hopefully raising the PHA to a safer orbit.

Each potential PHA impact mitigation method carries with it, its own set
of benefits and risks. A considerable risk associated with 'high-impact' mitigation techniques, such as the detonation of explosives at the surface
of the PHA, is fragmentation. This makes methods which gradually alter
the orbit of a PHA, and thus prevent the break up of such an object, look
like a less risky prospect. The tether system carries with it little risk
of causing fragmentation and smaller pieces of the PHA falling to earth, something which could itself cause widespread damage.

Using the asteroid Bennu as a test subject, the team used computer
simulations to calculate the dynamics of such a tether system for a
variety of different initial conditions, concluding that it would be
feasible for use as a planetary defence system. The team also suggest
that the system could be of use in both the study and potential mining
of NEOs and other asteroids.

One of the likely drawbacks of such a method is the fact that it could
require a longer lead time than many high impact methods which quickly
deliver kinetic energy to a PHA to knock it out of orbit. Thus, the
continued cataloguing of such objects is needed if such a method is ever
to be viable.


========================================================================== Story Source: Materials provided by Springer. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Flaviane C. F. Venditti, Luis O. Marchi, Arun K. Misra, Diogo
M. Sanchez,
Antonio F. B. A. Prado. Dynamics of tethered asteroid systems to
support planetary defense. The European Physical Journal Special
Topics, 2020; 229 (8): 1463 DOI: 10.1140/epjst/e2020-900183-y ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200618110955.htm

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