There are 434 known Potentially Hazerdous Asteroids near our planet!
Use this NASA orbit analyzer to check out the orbit of the
Asteroid 2003 KG4
A HUGE ROCK HURTLING TOWARDS EARTH!!
We may not get to see the next episode of Survivor after all!
Even Donald Trumps hair isn't safe anymore!
Yes it is true. The most dangerous objects flying towards you may not be a pair of silicon implants! It could be a big rock from outer space...and we're not talking about a big rock like the so-called rock band The Darkness who are also considered a danger to our planet...No...we are talking the end of the world in the most extreme sense of the verb...so just be carefull what you wish for because...hey...after all...
it might show up in a TV commercial after the smurf hits the fan!
|Fifteen years ago the mere idea of "Near-Earth Objects" (NEOs)
was a concept that gripped only a small group of astronomers and scientists.
The rest of us were too busy with the latest reality television shows
on TV. Most of us were too busy trying to figure out who should be voted
off the island or would be the next to hear the words "you're fired"
to bother thinking about such things as collosal chunks of granite hurtling
towards our planet. But today, if people stop chatting on their cellphones
long enough to think about the immense chaos of the universe, the entire
first world, in all their egostistical glory, has finally started to take
notice of the cosmic hail of bullets that is threatening us from beyond.
Let's take it from the beginning:
Asteroids are rocky bodies larger than 50 meters across. The largest of these known within near-Earth space is 1036 Ganymed, which has an estimated diameter of 41 kilometers (about 25 miles). The second largest is 433 Eros. This 23-kilometer (14-mile) asteroid will be the next target for the Near-Earth Asteroid Rendezvous (NEAR) mission launched in early 1996.
We can distinguish between a comet and an asteroid solely on the basis of the object's appearance through a telescope. If a newly discovered object appears fuzzy, then it is a comet. The "outgassing" that gives a comet its distinctive appearance is the result of ices vaporizing from the object's surface. It is likely that, for many comets, the surface ices evaporate completely after dozens of orbits around the Sun. If and when such extinct comets are found, their star-like appearance leads us to classify them as asteroids, even though they have a cometary origin.
Scientists categorize asteroids in near-Earth space as Atens, Apollos
or Amors. Names for each group come from their best known members --
2062 Aten, 1862 Apollo and 1221 Amor. At present, about 200 near-Earth
asteroids have been discovered. There are probably about 10,000 of these
objects larger than 0.5 kilometers (0.3 miles) in diameter, suggesting
that we have so far detected only a small percentage of their total
population. Scientists categorize objects displaying cometary properties
according to their orbital period. At present we only know of about
200 short-period comets -- a small fraction of their total population.
Although most have orbits that carry them well above and below the plane
of Earth's path, approximately 30 short-period comets have low enough
inclinations to make them accessible from Earth with modest propulsion
systems. Objects in this category include Giacobini-Zinner, the first
comet to be visited by a spacecraft -- the International Cometary Explorer
(ICE) in 1985 -- and Comet Encke, perhaps the most carefully studied
comet after Halley's Comet and Comet Hale-Bopp. The nuclei of these
comets, which are about 10 kilometers (6.2 miles) across, may store
virtually unaltered material from the early protoplanetary nebula. And
one of these materials -- water -- may prove to be a valuable resource
for future human space explorers.
According to one hypothesis, the fresh supply of asteroids comes from the asteroid belt, the region between Mars and Jupiter where nearly 20,000 objects have known orbits. A process called chaotic dynamics may remove these objects from the asteroid belt and place them on trajectories that bring them near Earth. Suspect supply areas include the famous Kirkwood gaps, highly depicted regions within the main belt that American astronomer Daniel Kirkwood first noted in 1867. The locations of these gaps correspond exactly to positions of mean motion resonances with Jupiter. At these locations, the orbital period of an asteroid is an exact integer ratio of Jupiter's. For example, at the 3 to I resonance, an asteroid completes exactly three revolutions in the time it takes Jupiter to complete one.
Danger from the Skies?
Surveys sponsored in part by The Planetary Society are just the beginning to achieve a census of the near-Earth population. Larger surveys, such as the Spaceguard Survey, can reveal the full nature of the near-Earth environment. Using the information these surveys collect, we can make careful plans to protect Earth from future cosmic impacts.
Richard P Binzel is the editor of The NEO News and an associate professor
of planetary science at the Massachusetts Institute of Technology.
Push the button >> to make it start....you can change the date and stuff too...it's cooool!!
1 AU = 1 Astronomical Unit = 149,597,871 kilometers
Additional Notes: the orbits shown in the applet are color coded. The planets are white lines, and the asteroid/comet is a blue line. The bright white line indicates the portion of the orbit that is above the ecliptic plane, and the darker portion is below the ecliptic plane. Likewise for the asteroid/comet orbit, the light blue indicates the portion above the ecliptic plane, and the dark blue the portion below the ecliptic plane.