What is the largest asteroid ever discovered called?
604080
Ceres is the most massive asteroid: it contains more than 30% of the total mass of all asteroids taken together.\n\nIt is also the largest asteroid and the first to be discovered on January 1, 1801 (easy to remember).
950664
I don't know the name, I think it just has a number.\n\nIt is about 1,000,000 km away and is a captured asteroid about 1km across.  It is irregular in shape.  It is in an unstable orbit and will eventually leave the Earth's orbit and enter solar orbit.
147446
A heffalump!\nBe afraid, be very afriad!\nhttp://disney.wretch.cc/mvdata/data/Pooh_Heffalump_Movie.jpg\n\nAs you probably know, the largest known animal on Earth is the blue whale. But most scientist believe that the blue whale is also the largest amimal that has ever lived.\nThey can weigh over 200 tons, so how can you beat that?\n\nBut as far as land animals go: the African elephant is the largest!\n\nAn extinct species of the rhinoceros called Baluchitherium grangeri was around 30 tons. That would be the largest land-dwelling mammal ever.\nThe largest dinosaur was the sauropod.\nhttp://www.dinosaurios.net/rama/rm_sale/rm_diplo01g.jpg
141215
i dont think anyone really knows for sure. probably like thousands of millions of years. unless it gets hit by a ginormus asteroid and explodes into teeny tiny peices!! lol
871143
Largest known to date is the "puffy planet" HAT-P-1b orbiting the sunlike star ADS 16402 B, one of a binary pair of G0 V stars 450 light yeard away, in the constellation Lacerta. Our sun is of spectral class G2 V i.e. a little cooler than ADS 16402 B.\n\nHAT-P-1b has a radius of 1.36 x the radius of Jupiter. \n\nIt was discovered on 13 September 2006 and is 450 light years away. It has the lowest density of any known extrasolar planet. It also has the name Krais.\n\nIt was announced as follows:\n\n"Using small automated telescopes in Arizona and Hawaii, the HATNet project has detected an object transiting one member of the double star system ADS 16402 AB. This system is a pair of G0 main-sequence stars with age about 3 billion years, at a distance of ~139 parsecs and projected separation of ~1550 AU. The transit signal has a period of 4.46529 days."\n\nNote: Only the radii of transiting planets are known.
282066
"Largest" is usually based on the overall mass of the animal, not just the length. While anacondas can get considerably longer than crocodiles, they aren't nearly as massive.
1034963
Xena, though the final verdict on whether it is the tenth planet is yet to come.\n\n2003 UB313 is a trans-Neptunian object (TNO) larger than the planet Pluto. It has been described as our solar system's tenth planet by its Mount Palomar-based discovery team, NASA, and some media outlets. The International Astronomical Union (IAU) is scheduled to publish the definition of the term "planet" in early September 2006, which will determine whether or not 2003 UB313 is classified as a planet. Its discoverer, Michael E. Brown, has given it the unofficial name "Xena".\n\n90377 Sedna is a trans-Neptunian object, discovered by Michael Brown (Caltech), Chad Trujillo (Gemini Observatory) and David Rabinowitz (Yale University) on November 14, 2003. At the time of its discovery it was the most distant observed natural solar system body, though this has now been exceeded by 2003 UB313. Sedna is described as a cold planetoid, perhaps as large as two-thirds the size of Pluto.\n\nA Planetoid is the term given to minor bodies orbiting the sun, that are bigger than meteoroids, but smaller than planets.
1039181
It is a theoretical planet. There have been numerous reports of finding it. It is most likely the same kind of thing as Pluto, which is an asteroid that gets lightly caught in the suns gravity. They are actually starting to think there are a lot of little asteroids that are "mini-planets" like that out past Pluto.
423720
Sure, in simple terms the main theory right now is that of a large meteoritic impact, proposed back in 1980.  It fits the requirement of a rapid and sudden kill-off event.  What killed the dinosuars?  Well the immediate effect of a large asteroid impact would be global firestorms.  The ejecta reaches low earth orbit and then superheats as it re-enters the atmosphere.  This pretty much covers much of the planet in fire.  Other bad things happen, toxic metals in the air and water, dust obscuring the sun, many bad things, but the main killing factor is the global fire storm.\n\nAs scientists we really like the asteroid impact theory as it is supported with the following eveidence (I have not heard any serious arguments about a double impact by the way):\n\n1. The boundry layer in which the extinction occured is ultra-rich in the element irridum.  These irridium levels are not found on earth, but match very well to those of meteoritic samples that we have.  This boundry layer with irridium has been found all over the globe.\n\n2. Shocked quartz deposits have been found in the regions near central to lower north america, indicating a large shockwave propagated across the area\n\n3. Tiny glass beads have been found in the same regions, with larger ones more concentrated near the Yucatan.  Thes glass bead are most closely related to objects we call Tektites, glass that forms from meteorite impact ejecta.  (cool science thing: you can get tektites for a couple dollars at any rock shop!)\n\n4. Tsunami deposits from that era have been found in the gulf of mexico region, indicating massive tidal wave events\n\n5. A crater caused an impact large enough to cause all of these things has been found right on the coast of the Yucatan, centered on Chicxulub, and dating to the right time period.
551304
Asteroid comes from Greek meaning 'starlike'. You know 'aster' = 'star'. It has nothing to do w/ the bum!!!\n\n;P
235413
Neptune has 13 known moons. The largest by far, and the only one massive enough to be spheroidal, is Triton, discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons, Triton has a retrograde orbit, indicating that it was captured, and probably represents the largest known example of a Kuiper Belt object (although clearly no longer in the Kuiper Belt). It is close enough to Neptune to be locked into a synchronous orbit, and is slowly spiraling inward. Triton is the coldest object that has been measured in the solar system.\n\nNeptune's second known satellite, the irregular moon Nereid, has one of the most eccentric orbits of any satellite in the solar system.\n\nFrom July to September 1989, Voyager 2 discovered six new Neptunian moons. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second most massive Neptunian moon, it is only one quarter of one percent of the mass of Triton. Neptune's innermost four moons, Naiad, Thalassa, Despina, and Galatea, orbit close enough to be within Neptune's rings. The next farthest out, Larissa was originally discovered in 1981 when it had blocked a star. This was attributed to ring arcs, but when Voyager 2 observed Neptune in 1989, it was found to have been caused by the moon. Five new irregular moons discovered between 2002 and 2003 were announced in 2004.
483988
A new object, 2003 UB303, was discovered in orbit beyond Pluto. It's preliminary name is Lila. There is still debate as to whether or not it is actually a planet or a large asteroid. This is the same as the current debate about Pluto.
330206
In the last few years of the 18 cetury (I estimate between 1793-1799) Baron Franz Xaver von Zach ordered a group of 24 astronomers to find a "missing planet" (the planet we know now as neptune) to solve the mystery of uranus's strange rotation.  However, the first asteroid discovered, 1 ceres, was discovered by accident by Giuseppe Piazzi.  Later, there were several other found.  The ammount keep going on through today!
669912
An asteroid is a small, solid object in our Solar System, orbiting the Sun. An asteroid is an example of a minor planet (or planetoid). These minor planets are much less massive than even small planets such as Mercury or Mars. It is believed that most asteroids are remnants of the protoplanetary disc. The incorporation of these remnants into the planets during the formation of the Solar System was prevented by large gravitational perturbations induced by Jupiter. Some asteroids have moons. The vast majority of the asteroids are within the main asteroid belt, with elliptical orbits between those of Mars and Jupiter.
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.
825274
There are some 432,536 asteroids at the latest count. Less than 5,000 of these are Near Earth Objects i.e. come inside the orbit of Mars.\n\nThe two you may have heard about are 99942 Apophis (320 metres in diameter) and 29075 1950 DA (1.1 - 1.4 kilometres in diameter).\n\n1950 DA\n\n29075 1950 DA is the Near Earth Object with the highest known possible probability of impacting Earth, according to the Palermo Technical Impact Hazard Scale. For a few days in December 2004 it was temporarily surpassed by 99942 Apophis (which at the time was named only by its provisional designation 2004 MN4).\n\nIf 1950 DA continues on its present orbit, it will approach near to the Earth on March 16, 2880. Over the intervening time, the rotation of the asteroid will cause its orbit to change (by the Yarkovsky effect). (See second link.)\n\nA preliminary analysis shows two possible pole directions (Giorgini, et al., 2002 "Asteroid 1950 DA's 2880 Encounter with Earth"). One trajectory misses the Earth by tens of millions of kilometers, while the other has an impact probability of 1⁄300. The radar observations are currently being reanalyzed, in combination with the optical lightcurves.\n\nThe energy released by a collision with an object the size of 1950 DA would cause major effects on the climate and biosphere which would be devastating to human civilization.\n\nThe discovery of the potential impact has heightened interest in asteroid deflection strategies. (See third link.) \n\nDespite the fatalism of one contributor above, there is plenty that could be done about avoiding an impact, especially with over 800 years notice of one!\n\nAPOPHIS\n\nIn July 2005, former Apollo astronaut Rusty Schweickart formally asked NASA to investigate the possibility that the asteroid's post-2029 orbit could be in orbital resonance with the Earth, which would increase the probability of future impacts. Schweickart asked for an investigation of the necessity of placing a transponder on the asteroid for more accurate tracking of how its orbit is affected by the Yarkovsky effect.\n\nIf this project were undertaken, we would have a spy in the sky to tell us of any impending problems. This is just one example of how mankind can intervene in its own destiny.\n\nDISCOVERY AND NAMING \n\nApophis was discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi of the NASA-funded University of Hawaii Asteroid Survey from Kitt Peak National Observatory in Arizona. This group observed for two nights. The new object received the provisional designation 2004 MN4.\n\nOn December 18, the object was rediscovered from Australia by Gordon Garradd of the Siding Spring Survey, another NASA-funded NEA survey. Further observations from around the globe over the next several days allowed the Minor Planet Center to confirm the connection to the June discovery.\n\nWhen first discovered, the object received the provisional designation 2004 MN4 and news and scientific articles about it referred to it by that name. When its orbit was sufficiently well calculated it received the permanent number 99942 (on June 24, 2005). Receiving a permanent number made it eligible for naming, and it promptly received the name "Apophis" as of July 19, 2005. Apophis is the Greek name of the Ancient Egyptian god Apep, "the Destroyer", who dwells in the eternal darkness of the Duat (underworld) and tries to destroy the Sun during its nightly passage.\n\nPOSSIBLE IMPACTS\n\nApophis has an orbital period of 323.6 earth days and crosses our orbit twice a year. Only a minority of its approaches will find us at a point of our orbit where an impact may occur.\n\nThe 2029 approach was thought at first to be potentially hazardous, but further observations ruled that out. Then an impact in 2035 was considered a possibility and further observations then ruled that out, too.\n\nOn August 5, 2006, Apophis was lowered to a Level 0 Torino impact hazard scale. As
993967
several large asteroids have earth-crossing orbits, but we know of no asteroids that will come close to us at this time.  Odds are, if an asteroid that was 1 mile across or bigger coming at us soon, we wouldn't know it at all in advance.  We're working on finding them all and getting their orbits mapped.