Jupiter, the largest planet in the solar system, has long been perceived as an active protector of the inner solar system from dangerous comets and asteroids and acting as a gigantic celestial shield in space, known as the Jupiter Shield theory.

But now, the theory is under radar after a new study found that instead of deflecting, the planet is sling-shooting objects into the inner solar system that could have devastating impacts on Earth and can even cause mass-extinction events.

Jupiter and asteroids
Jupiter is shooting objects into the inner solar system that could impact the Earth NASA

Kevin Grazier explains the process

Space expert Kevin Grazier has questioned the theory and published several paper, including one published in the Astronomical Journal in 2018 and the other in the monthly notices of the Royal Astronomical Journal in 2019. Grazier's papers explained his stand as to why he feels that Jupiter is a 'sniper rather than a shield'.

In his first paper, the scientist analyses the complex ways in which objects in the outer solar system are affected by the Jovian planets such as Jupiter, Saturn, Neptune, and Uranus, while in the second paper Grazier focused at a specific family of icy bodies and how they're transformed into potentially deadly comets by Jupiter.

"Actually, I wouldn't say that it's in jeopardy -- I would say that it has been laid to rest," Grazier commented about the Jupiter Shield Theory. "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."

Planet Jupiter a shield or not?

Grazier collaborated with NASA's Jet Propulsion Laboratory and the university of Southern Queensland to demonstrate how Jupiter could turn passing objects into potentially Eath-threatening comets. However, Grazier has also admitted that though his models can show how Jupiter picks up debris into its orbit and flings it out, the planet can also act as a shield in some cases.

Grazier said: "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."