Asteroid belt: an exploded planet?
552556
It is certainly possible that some of the many tiny moons of the larger, gas giant, planets could have come from the asteroid belt.  Those massive planets' gravitational field are prone to capture a lot of debris from the solar system.\n\nWow, FishRN, it must have taken a lot out of you to copy paste that whole thing from the wikipedia article, so much so that you couldnt even list your source.\nhttp://en.wikipedia.org/wiki/Asteroid_belt
824414
The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found.
335043
Yes. Here's the proof: There has been talk that the asteroid 1997XF11 will crash into the Earth in the year 2028. The bottom line is that this asteroid poses no threat to the planet Earth in the next century. But, it will pass by the Earth over and over again in the next centuries, so it is worth knowing what our countermeasures are if it ever gets too close!\n\nRight now, they have the technology to divert a comet or asteroid coming towards the Earth. Our rockets and explosives would be sufficient to break apart even a large object of about 1 kilometer in diameter. We would of course need some lead time (10 years would be a nice minimum notice). Blowing up an asteroid or a comet too near to the Earth, would just create a chaotic mess of smaller pieces flying towards the Earth. If we were to discover an object coming towards the Earth with only 1-2 years notice before impact, our technologies might not be adequate. The best we could hope to do would be to evacuate the impact site. So the best plan right now is to continue surveying for Near Earth Objects, so that we will know where these asteroids and comets are in time to prepare any countermeasures that might be necessary.
508585
There have been many systems identified, some with multiple planets and a few with asteroid belts. The problem is that they are mostly discovered by measuring the minute movements of the star caused by gravitational influences of nearby orbiting objects, so most of the discoveries to date have been systems with relatively large planets (many times larger than our Jupiter) and quite close to the star so that the movement is more easily detected. Recently however, there have been more sensitive sensor arrays which have been able to resolve more "normal" configurations using sophisticated imagery, so there is hope for discoveries of systems more similar to our own in the near future. In any event, given the tremendous distances involved, the resolution of optical telescopes available in the foreseeable future would pretty much preclude any traditional photograph of such a system if it were to be found. There have been some rather blurry computer images generated from these other imaging systems, but I'd hardly call them photographs. Try monitoring <space.com>
777012
i suppose a planet.cause it is denser then asteroids
227911
The inner planets are the 4 planets who's orbits are closest to the sun (Mercury, Venus, Earth, and Mars).  The asteroid belt (and millions and millions of miles) seperates the inner planets from the outer planets.\n\nCompared to the distances in between the outer planets, the inner planets might as well be right next to eachother, the distances really start getting big in the outer solar system.
749360
There are no earth size asteroids. The earth is the 6th largest object in the solar system after the Sun and the 4 gas giants and bigger than Mars Venus and Mercury. So if there were an object as big as the Earth and therefore bigger than Mars Venus and Mercury, it would have long ago been classified as a planet, not an asteroid!\n\nYou appear to be unaware that there is international co-operation between NASA, the European Space Agency and others on a project called Spaceguard. which keeps an eye open for asteroids, comets and other objects that may perhaps be on a collision course with the Earth.\n\nThe term Spaceguard loosely refers to a number of efforts to discover and study near-Earth objects (NEO). Arthur C. Clarke coined the term in his novel Rendezvous with Rama where SPACEGUARD was the name of an early warning system created following a catastrophic asteroid impact on Italy. This name was later adopted by a number of real life efforts to discover and study Near-Earth Objects.\n\nA 1992 U.S. Congressional study produced a "Spaceguard Survey Report" which led to a mandate that NASA locate 90% of large near-Earth asteroids within 10 years\n\nWe know as of September 2006 of some 342,536 asteroids, But of these. only a relatively small number come inside Mars' orbit and less than 5,000 are classed as Near-Earth Objects.\n\nAs of August 31, 2006, 4,187 NEO's have been discovered: 57 near-Earth comets and 4,130 near-Earth asteroids. There are 792 NEO's which are classified as potentially hazardous asteroids.  \n\nEstimating the risks\n\nThere are two schemes for classification of impact hazards: the simple Torino Scale and the more complex Palermo Technical Impact Hazard Scale \n\nOn 25 December 2004, minor planet 99942 Apophis was assigned a 4 on the Torino scale, the highest rating so far. At 27 December 2004 there was a 2.7% chance of Earth impact on the 13 April 2029. However, on 28 December 2004, the risk of impact dropped to zero for 2029, but, due to a resonant return possibility the Torino rating for an April 2036 impact rose to 4 in early 2005 and, as of August 2006, has dropped gradually to a Torino rating of 0 (zero). The Palermo rating (August 2006) is −2.25.\n\nOnce the Spaceguard community is alerted to a potential impactor its orbit is immediately studied in great detail to get a more accurate projection of whether there will be an impact scenario or not. \n\nAs you can see the immediate threat anticipated on 25th Dec 2004 of an impact 25 years later was able to confidently be rejected, 3 days later. Word went round immediately there was an alert and the work needed was done, even though it was Christmas.\n\nSo the astronomers are on the case. and the paranoid should not let their uninformed imaginations run riot.\n\nCurrently, the only known NEO with a Palermo scale value greater than zero is (29075) 1950 DA, which is predicted to pass very close to or collide with the Earth (p≤0.003) in the year 2880. If this collision were to happen, the energy released by a collision with (29075) 1950 DA would cause an extinction event which would destroy most life on the planet. However, humanity has over 800 years to refine its estimates of the orbit of (29075) 1950 DA, and to deflect it if necessary.\n\nNASA maintains a continuously updated web page of the most significant NEO threats in the next 100 years - all or nearly all of which are highly likely to drop off the list eventually as more data comes in enabling more accurate predictions; however, that page does not, of course, include 1950 DA, because that will not strike for at least 800 years.\n\nSo it is down to vigilance so as to anticipate danger, precision so as to quantify it, and technical knowhow, so as to avert it.
1170805
Well that is a very good question, and one that is being debated as we speak. We now know that Pluto is much smaller than we previously thought (it is a very small planet and a moon) And we have now discovered a very large asteroid that some people want to call planet 10. In fact some people want to reclassify Pluto as they think it is too small to be called a planet.\n\nThe problem is that there is really no "exact" definition of what a planet is. I mean obviously a large body that orbits a star, is part of the definition. but when you get to smaller objects in irregular orbits, are they planets? planetoids? asteroids? something else?\nSo as for how large does an object have to be?\nwe will have to wait for the IAU (International Astronomical Union)\nto come up with a rigidly defined definition.\n\npersonally, I say an object that has enough mass to cause gravity to shape it into a sphere and has its own atmosphere should be called a planet. But hey that is just my personal opinion.\ncheck out these articles.\n\nhttp://news.bbc.co.uk/2/hi/science/nature/259767.stm\n\nhttp://www.space.com/scienceastronomy/planet_denitions_030227.html
568351
Nuke it, propel it away with rockets, or just accept it.  \n\nhttp://search.yahoo.com/search?p=protect+the+earth+from+a+major+asteroid+impact+&toggle=1&ei=UTF-8&xargs=0&pstart=1&fr=FP-tab-web-t-403&b=11
586535
A continuing effort to identify even near Earth asteroids which are relatively easy to track and have a greater possibility of collision is still incomplete, with only a fraction of their orbits plotted. Since the orbital periods of comets and other Oort cloud entities are in the tens, hundreds, or even thousands of years, many of these objects have never been seen in recorded history, much less their orbits calculated and possibility of collision with Earth evaluated. With this in mind, an event such as this might be possible at any point in the future, although since objects from the outer solar system tend to be rather reflective, chances are that they would be spotted and we would have some advance warning of a likely intersection with Earth orbit presenting a cause for concern. That said, the chance of it happening in any particular year is extremely remote, the likelihood of it happening sometime in the next several million years greater.
354331
The asteroid belt idiot.  The closest star is 27 trillion miles away!
556842
The truth is ...\nAn asteroid discovered just weeks ago has become the most threatening object yet detected in space. \nA preliminary orbit suggests that 2002 NT7 is on an impact course with Earth and could strike the planet on 1 February, 2019 - although the uncertainties are large. \n\nAstronomers have given the object a rating on the so-called Palermo technical scale of threat of 0.06, making NT7 the first object to be given a positive value. \n\nFrom its brightness, astronomers estimate it is about two kilometres wide, large enough to cause continent-wide devastation on Earth.
701683
My opinion is that we would have to change course of an asteroid headed for Earth.  That means that we would have to detect it years in advance.  With enough notice, we could build a Nuclear Electric Propulsion (NEP) system.  Actually we would have to build several and attach them to the asteroid and start pushing.   They would need to be refueled, so we have to make several visits.   If successful, a project like this would be a real boon to the space program, the economy, and scientific knowlege.
1037864
There are a large number of balls of ice and rock of various sizes scattered around the solar system. Some are small enough that they are irregularly shaped. Some have highly elliptical orbits. Some are very, very small.  So part of the difficulty is that there is not an agreed upon definition of what a 'planet' really is. By one definition, Pluto is not a planet, but rather is the first of a class of medium sized balls of ice and rock to be discovered at the edges of our system (the Kuiper belt objects). There are many others, some of which are comparable in size. Furthermore, these objects are far enough away from the sun that they don't reflect much light back to us, so they are very hard to locate.\n\nOn the other hand, we can estimate the distances to some fairly bright galaxies and determine that they are billions of light years away. That means that the light from these galaxies has taken a billion years to get to us. That, in turn, means that we are seeing now what happened there billions of years ago. This allows us to say what the universe was like at that time with some confidence.
1026139
It's Asteroid 2003 YN107, and it has been looping around the earth for seven years. :)\n\nEdit: Well, according to NASA as of June 9, 2006 anyway ^_^. Oops, I've just read that it's about to leave the earth; it was just corkscrewing around the planet.\n\nYeah, I think Sunil's right, its Cruithne.
382749
are they sure that it will hit earth in that year? Maybe it will hit earth much later, or maybe they'll find a way to stop it. I don't know, the size, but asteroids sure are large, but maybe it'll be just a small collision that the earth will not split up and humankind will not be...destroyed.
522372
No, Because only one asteroid is that big. It is named Ceres and we know it's orbit very well it never comes anywhere near Earth.