Jupiter is flinging asteroids at Earth ‘like a sniper’, top scientist warns Jupiter is being accused of actively flinging dangerous objects into the inner solar system that could impact Earth. Some space experts believe the huge planet protects Earth from comets and asteroids but new research has suggested that it may actually be doing the opposite. The popular Jupiter Shield theory proposes that the planet acts like a giant space shield due to its huge mass causing it to suck in or deflect dangerous debris However, this shield theory is slowly falling out of favor and one of the leading critics is space expert Kevin Grazier. He's published several papers explaining why he thinks Jupiter is a "sniper rather than a shield". Recently, he's been aiming to prove how this 'sniper-like' process works. Grazier's extensive work could put the Jupiter Shield theory in jeopardy. He told Gizmodo: "Actually, I wouldn’t say that it’s in jeopardy—I would say that it has been laid to rest. "Our simulations show that Jupiter is just as likely to send comets at Earth as deflect them away, and we’ve seen that in the real solar system." Grazier's work provides new scientific models that demonstrate the complex processes behind how a celestial object can be turned into a threat. He collaborated with Nasa’s Jet Propulsion Laboratory and the University of Southern Queensland to demonstrate how Jupiter could turn passing objects into potentially Earth-threatening comets. Both Grazier and his colleagues have admitted that although their models can show how Jupiter picks up debris into its orbit and flings it back out, the planet can also act as a shield at the same time. Jonti Horner, an astronomer at the University of Southern Queensland, told Gizmodo: "It takes things that threaten Earth and flings them away, clearing space near our planet. "So in that sense, it is something of a shield. "On the flip side, though, it takes things that come nowhere near Earth and flings them our way, meaning it is also a threat. "To find out which side is more important—to determine whether Jupiter is truly friend or foe—you need to look at the story in some detail." Grazier added: "We already know that Earth is in the cosmic cross-hairs. There are hundreds of near-Earth objects that are potentially hazardous. "I think we now just have to pay more attention to what’s happening a bit farther away in Jupiter’s neighborhood." Comet and asteroid strikes are such a cause for concern because they can have devastating impacts on Earth and can even cause mass-extinction events. However, comets and asteroids hitting Earth when it was young are thought to be the reason that it had the essential ingredients to create life in the first place.