Instructions: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Input: A giant crater at the moon's south pole may hold the answer to a long-standing mystery about why portions of the lunar crust have a magnetic field and other parts don't.After running sophisticated computer models, a trio of researchers is suggesting that mysterious magnetic material detected on the surface was delivered by a 120-mile-wide asteroid that crashed into the moon about 4.5 billion years ago. The collision left behind a gaping hole on the far side of the moon that is one of the largest-known impact craters in the solar system.The South Pole-Aitken basin is "this huge, whopping crater that's roughly half the size of the U.S.," said Mark Wieczorek, lead author of a paper about the discovery published in Friday's edition of the journal Science. The presence of magnetized patches near its northern rim led Wieczorek and his colleagues to think there might be a connection.The moon doesn't have a global magnetic field as the Earth does, but things may have been different in the distant past.Scientists have detected local magnetic fields in moon rocks and from measurements taken from space, and that leads them to believe that some moonwide field most likely existed at some point. The field could have been generated by energy from asteroid impacts or a dynamo in the moon's metallic core that long ago petered out.Lunar magnetism has no direct impact on the Earth. But scientists are interested in it because it offers a window into the moon's early history — and, since the moon is thought to have broken off from a young Earth, ours as well, said William Bottke, director of the Center for Lunar Origin and Evolution at the Southwest Research Institute in Boulder, Colo., who wasn't involved in the study.Researchers have wondered about the moon's regions of strongly magnetized rock ever since the Apollo 12 crew discovered them in 1969, said Wieczorek, a planetary scientist at the Paris Institute for Global Physics.The magnetic anomalies didn't seem to correlate with any geologic structures that might hold clues about their origins — features such as craters, volcanoes or lava flows. Typical moon rocks have a low iron content, which means that they don't have great potential to become magnetized in the first place.Throw in the moon's present lack of a magnetic field, some sort of which would have been needed to magnetize the rocks, and planetary scientists were stumped.But as spacecraft gathered more data on the South Pole-Aitken basin, Wieczorek and colleagues Benjamin Weiss and Sarah Stewart, both of Harvard University , began to think that the 1,200-mile-wide basin might be involved.The formation is slightly elliptical in shape, suggesting that it was created by an oblique impact from a very large object. The most likely candidate would be an asteroid, which can be 10% to 30% metallic iron by weight and about 100 times more magnetic than typical lunar materials, Wieczorek said.A powerful, angled hit would have sprayed iron material downrange from the impact — corresponding, potentially, to where strong magnetic anomalies had been mapped.If the moon did have a magnetic field at the time of the impact 4.5 billion years ago — a distinct possibility, Wieczorek said — then the metallic debris could have been magnetized as it cooled, leading to the puzzling arrangement of magnetic regions that exists today.The team tested the theory by running computer simulations of impacts. Varying a number of parameters, including the velocity and impact angle of the asteroid as well as its composition and size, they determined that the scenario that best fit the observations was an asteroid hitting the moon at a 45-degree angle while traveling about 9 miles per second.Such an impact would have been normal, Wieczorek said. "We don't require improbable conditions."Others who study the moon said that the team's hypothesis would help researchers get to the bottom of the lunar magnetism mystery."I think it's a good idea. I'm surprised no one really explored it earlier," said Ian Garrick-Bethell, a professor of planetary science at UC Santa Cruz.But some weren't convinced that Wieczorek and his colleagues were on the right track.Lon Hood, a senior research scientist at the Lunar and Planetary Laboratory at the University of Arizona in Tucson, believes that the anomalies were created by more recent impacts on a different part of the moon, which he said correlate more cleanly with evidence from the lunar surface."I wish the moon was simpler than it is," he said.Wieczorek said the next big problem to solve is how and when a magnetic field developed on the moon.Ultimately, the best way to get to the bottom of it all, he added, would be to go back to the moon and collect samples. ||||| by editor 
  
 In the nearly five decades since the first lunar surveys were conducted as part of NASA's Apollo program, scientists have advanced a number of increasingly complex theories to explain the vast swaths of highly magnetic material that had been found in the some parts of the Moon's crust. 
  
 But now a team of researchers from Harvard, MIT and the Institut de Physique du Globe de Paris, have proposed a surprisingly simple explanation for the unusual findings — the magnetic anomalies are remnants of a massive asteroid collision. As described in a paper published March 9 in Science, the researchers believe an asteroid slammed into the moon approximately 4 billion years ago, leaving behind an enormous crater and iron-rich, highly magnetic rock. 
  
 While there is evidence that the Moon once generated its own magnetic field, there is little to suggest it was strong enough to account for the anomalies seen in earlier surveys, Sarah Stewart-Mukhopadhyay, the John L. Loeb Associate Professor of the Natural Sciences, and one of three co-authors of the paper, said. To explain the findings, then, researchers turned to a number of elaborate scenarios. 
  
 "The conundrum has always been that the magnetism we see on the Moon is not correlated with any surface geology," she said. "The theory that has been most commonly cited to explain it is an 'impact-induced field,' in which an impact concentrates and amplifies the Moon's magnetic field. But it was difficult to test — people have tried to model it, but it is right at the edge of what could work. 
  
 "We have a simpler idea," she continued. "Because the fields in this area are stronger than those found in any normal lunar rocks, our hypothesis is that it isn't lunar material. We know the magnetic properties of asteroidal material are much higher than that of the Moon. It is possible that metallic iron from an asteroid could have been magnetized by the impact, and deposited on the Moon." 
  
 Ironically, their first clue came from the surveys that had long confounded scientists. 
  
 When combined with more recent, hyper-accurate topographical surveys of the Moon's surface, it quickly became clear that most of the magnetic anomalies are scattered around the rim of an enormous, 2,400 kilometer-diameter crater known as South Pole-Aitken. 
  
 The oldest definitive structure on the Moon, the crater is between 3.9 and 4.5 billion years old, and is slightly elongated, suggesting it was formed by an object that struck the moon at an oblique angle. 
  
 Testing that hypothesis, however, proved tricky. 
  
 "The question was whether the projectile material could survive and stay on the Moon, and where it would end up," Stewart-Mukhopadhyay said. "What I did was model the impact and formation of the basin using computer codes that are typically used to model explosives." 
  
 To create those models, Stewart-Mukhopadhyay started with "equations of state," mathematical formulas that describe the asteroid and the Moon's crust, mantle and core. The far trickier part of modeling the impact, however, is in describing the rheology — the conditions under which each material deforms and flows. 
  
 "We modeled a number of scenarios using faster or slower impacts and more shallow or more vertical angles," she said. "Each time, the model produced similar results to what we see on the Moon." 
  
 Beyond its surprisingly simple explanation to a decades-old scientific puzzle, the paper suggests new ways to answer questions about what the early solar system was like, and how the magnetic fields of the planets were formed. 
  
 "We don't have much evidence of what was hitting the Earth before 3.9 billion years ago," Stewart-Mukhopadhyay said. "And there are some big questions about where those projectiles were coming from. Presumably if you picked up even the soil from this part of the Moon, you would have some of the material that came along with this large impact event. 
  
 "It may also be true that extra-terrestrial materials play a larger role in the magnetic fields of other planets than anyone has appreciated," she continued. "Magnetism is one of the clues that let us construct a geologic history of the surface of a planet. If we now have to consider that it may have come from a collision like this one, that's something we need to be aware of." 
  
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Output:
One of the moon's oddest anomalies is how parts of its crust have a magnetic field and others don't. But now scientists say they have a relatively simple theory for this inconsistency—a 120-mile-wide asteroid that smashed into the moon's south pole 4.5 billion years ago left behind magnetic rock, reports the Los Angeles Times and Red Orbit. The collision left "this huge, whopping crater that's roughly half the size of the US," says the paper's lead author. The asteroid may have struck in an area where the moon once had a magnetic field, which would have magnetized the asteroid's iron-rich rock. "I think it's a good idea," says a planetary science professor at UC Santa Cruz. "I'm surprised no one really explored it earlier." But not everyone is convinced, as other astronomers think the magnetic anomalies are the result of smaller and more recent impacts. "I wish the moon was simpler than it is," says one.