Both Jupiter and Saturn play a significant part in the Earth's existence. In a study published in the journal Astrobiology, researchers revealed that Saturn acts as a primary protector of Earth, slinging away space debris that poses a danger, and Jupiter delivers what's called as "life-enabling volatiles" to the planet.
According to a report from Seeker, Jupiter has always been hailed as a "planetary shield".
Author of this new study and planetary scientist Kevin R. Grazier of NASA's Jet Propulsion Laboratory said that the gas giant's reputation as the major protector of Earth began with a misinterpretation of George Wetherill's 1984 paper in Astrophysics and Space Science. Here, he said that star systems with smaller planets -- those that measure only up to the size of Uranus, Neptune or smaller -- tend to eject fewer comets back into interstellar space. It indicates that size plays a significant part in shielding planetary bodies. Wetherill described it as the "absence of Jupiters," but it should be noted that if size is what's important, Jupiter is not the only large planet in the solar system.
"You see [Jupiter's influence] recreated all the time in documentary TV shows," Grazier pointed out, adding that Saturn is a massive planet as well. "I just thought about that [theory] and I said, 'I don't believe that for a moment.'"
Grazier attempted to replicate Wetherill's work using modern and more powerful technology. His simulations reveal that small bodies between Jupiter and Saturn, such as asteroids and comets, typically get ejected -- most of them after already passing into the solar system. Furthermore, it takes both planets to consistently kick out these space debris. In simulations where either Jupiter or Saturn is dropped, less small bodies get ejected.
However, it's shown that Saturn actually plays a bigger role in shielding Earth compared to its larger partner. On the other hand, Jupiter brings volatiles such as water to the inner solar system planets including Earth.