Earth's orbit threatened by passing stars
Astronomers Nathan Kaib and Sean Raymond found that if a star passes close enough to our solar system, it could mess with the orbits of planets—including Earth.
A Sun-like star flying by within 10,000 astronomical units might trigger chaos in the Oort Cloud and make Mercury's orbit way more unstable.
A stellar flyby might trigger these events
The research shows that a stellar flyby could set off rare but wild events: Venus or Mars could crash into Earth, or Earth itself could get flung out of the solar system—or even pulled into the Sun.
The odds are tiny (about 0.2% for Earth over five billion years), but Pluto and Mars face slightly higher risks of orbital trouble.
Future of solar system may be more unstable than thought
Earlier models didn't factor in these passing stars, so scientists may have underestimated how shaky our solar system's future really is.
As Kaib noted, flybys can significantly increase instability.
Raymond emphasized that understanding these outside influences is key to predicting what happens to our planets down the line.