Asteroid impact avoidance.pdf


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Asteroid impact avoidance
Asteroid impact avoidance comprises a number of methods by which nearEarth objects (NEO) could be diverted, preventing destructiveimpact events.
A sufficiently large impact by an asteroid or other NEOs would cause,
depending on its impact location, massive tsunamis, multiple firestorms and
an impact winter caused by the sunlight-blocking effect of placing large
quantities of pulverized rock dust, and other debris, into thestratosphere.
A collision between the Earth and an approximately 10-kilometre-wide
object 66 million years ago is thought to have produced theChicxulub Crater
and the Cretaceous–Paleogene extinction event, widely held responsible for
the extinction of mostdinosaurs.
While the chances of a major collision are not great in the near term, there is
a high probability that one will happen eventually unless defensive actions
are taken. Recent astronomical events—such as the Shoemaker-Levy 9
impacts on Jupiter and the 2013 Chelyabinsk meteor along with the growing
number of objects on the Sentry Risk Table—have drawn renewed attention
[1]
to such threats. NASA warns that the Earth is unprepared for such an event.

Contents
1

Deflection efforts
1.1
History of government mandates
1.2
Ongoing projects
1.2.1
Sentinel Mission
1.3
1.4
1.5

Prospective projects
Detection from space
Deep Impact

2

Impact probability calculation pattern

3

Collision avoidance strategies
3.1
Nuclear explosive device
3.1.1
Stand-off approach
3.1.2
Surface and subsurface use
3.1.3
Comet deflection possibility
3.1.4
Present capability
3.1.5
Law
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9

Kinetic impact
Asteroid gravity tractor
Ion beam shepherd
Use of focused solar energy
Mass driver
Conventional rocket engine
Asteroid Laser Ablation
Other proposals

4

Deflection technology concerns

5

Planetary defense timeline

Artist's impression of a major impact event.
The collision between Earth and an asteroid
a few kilometres in diameter would release
as much energy as the simultaneous
detonation of several million nuclear
weapons.