Earth could be ejected from the solar system, new study suggests

Although the Sun’s demise—turning into a red giant—is expected in about 5 billion years, the fate of the solar system could be far more uncertain in the meantime than previously thought. A new study suggests that passing stars could significantly disrupt the orbits of planets, potentially leading to Earth being flung out of the solar system.

Simulations conducted by Nathan Kaib (Planetary Science Institute) and Sean Raymond (University of Bordeaux) analysed scenarios in which other stars pass near the Sun over the coming billions of years. As ScienceNews reports, the researchers found that, on average, 19 stars pass within one parsec (3.26 light-years) of the Sun every million years, closer than our nearest star, Proxima Centauri, which is 4.25 light-years away.

Earth could be ejected from the Solar System: But not anytime soon

These close encounters can cause significant disturbances. Mercury is particularly vulnerable to instability due to its already elongated orbit and the gravitational influence of Jupiter. According to the study, a passing star could provide enough gravitational momentum to throw Mercury’s orbit into chaos, sparking a domino effect across the inner solar system.

Under such scenarios, Mercury frequently crashes into the Sun or Venus, setting off cascading changes that alter the orbits of Venus, Mars, or even Jupiter. For Earth, this could end in one of three catastrophic outcomes: a collision with another planet, a crash into the Sun, or being ejected into deep space, far from any source of heat or light.