Spitzer Space Telescope
A passing star may have buzzed the solar system billions of years ago, sending thousands of small icy worlds beyond Neptune’s orbit careening into interstellar space and leaving others in wildly tilted paths around the sun.
This scenario, dreamt up by Susanne Pfalzner at the Max Planck Institute for Radio Astronomy in Bonn, Germany and her colleagues, could explain some unusual features of the outer system.
Certain objects beyond the orbit of Neptune have very inclined and elongated orbits, relative to the rest of the …