
The highly tilted orbit of Eris compared to the orbits of Ceres (light blue), Jupiter (maroon), Saturn (orange, Uranus (green), Neptune (blue), Pluto (olive, and MakeMake (red) [image credit: Fandom]
Could a ‘rogue’ star passing nearby have disturbed outer parts of the early solar system? Beyond Neptune things become somewhat different.
The outer reaches of our solar system harbor a number of mysterious features. Astrobites reports on whether a single stellar fly-by could help explain them all.
A star is born from the gravitational collapse of a cloud of gas and dust. Yet not all of the material ends up in the star, and instead forms a flat protoplanetary disk that surrounds the new star. Over time, the materials in this disk coalesce to form planets, moons, asteroids, and most other objects you might expect to find near a typical star.
Since protoplanetary disks are flat, the expectation is that all of the planets and objects orbiting a star that formed out of a protoplanetary disk should orbit on a single plane. So when we find stars with planets that orbit at multiple different inclinations, this raises questions.
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