NEO stuff page of Joachim Köppen
Here I collect links pertaining to NearEarthObjects and their possible
collisions with Earth.
NASA asteroid and comet impact hazards
MIT's LINEAR asteroid search program
Near Earth Asteroid Tracking system
Uni.of Arizona's Spacewatch program
- Lowell Observatory
Tunguska Home Page at the Physics dept. at the
University of Bologna
U.K. NEO Information Centre
NASA JPL pages
Proceedings of the Planetary Defense Workshop
at LLNL, May 22-26, 1995
simulates the collision of an asteroid with the Earth, in a simple
two-body treatment. It shows the effects of "gravitational focussing",
and that for small approach speeds the Earth presents a larger
effective cross section than its geometric cross section.
allows to study the effect of exploding an asteroid or trying
to deflect it in order to avoid collision of the asteroid with Earth.
This takes place in the gravitational sphere of influence of the
Earth, and addresses what could be done in the very last moments.
Comet Halley's Orbit in the Solar System
is an application of the wonderful Applet OrbitViewer by O.Ajiki and
R.Baalke to the comet Halley. It allows to view the positions of the
planets at any time and to view their orbits from any angle.
Asteroid 1997 XF11's Orbit in the Solar System
Orbits and Travels in the Solar System
uses Keplerian orbits to show how a body travels through the
Solar System, such as a planet, asteroid, or comet. We can inspect
the body's distance from Earth, and see how it could be detectable
by its brightness or velocity. We can also launch a probe from Earth
to intercept the body.
Trip to Jupiter: Schedule departure and
is an extended version. It uses Keplerian orbits to compute the time
windows available for travelling from the Earth to another body
orbiting the Sun, such as a planet, asteroid, or comet. For these
mission windows, it displays the various properties of the mission,
such as departure and arrival speeds, orbital eccentricity and period.
It thus allows to optimize an interplanetary space mission.
Near Earth Objects
are judged to be potential hazards to the Earth. This applet allows
to show how such an object on collision course could be detected
from Earth before the collision, and to estimate the effects of the
impact on the Earth surface. We can also try to find the orbital
trajectory for an intercepting mission.
Hit and Deflect a Near Earth Object
is an extension of the above applet: it also allows to find the launch
windows for an intercept mission, and to estimate how much it would
take to try to deflect the body sufficiently to avoid the collision with
displays on a map of NEO diametre and the speed at its impact on
Earth various data: the energy of the impact (to judge how severe
the consequences of such an event would be). Then the time
before collison at which the body could be detected, given a limiting
visual magnitude. And the energy that would be required to cause
a given deflection of the trajectory, depending on the time of launch
and the speed of an interceptor. All calculations are done in a rather
rough approximation, that the NEO approaches on a straight line
at constant speed. This neglect of the effects of gravity by the Earth
and by the Sun limits such a study to fast objects, but one can still
get a rather good impression about the principal issues.
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last update: 8 Nov. 2010 J.Köppen