What heavenly body is believed by some scientists to have been captured by the sun's gravity rather than originally forming in our solar system?

• A. Pluto
• B. Eris
• C. Ceres
• D. Planet X

Answer: (A)

Gravitational capture is when a body that didn’t form in the Sun’s local neighborhood ends up bound to the Sun, usually through complex gravitational interactions in the early Solar System. Pluto fits this idea because it is a distant, small icy world with an orbit that is notably different from the planets’ orbits, which has led some scientists to propose that it could have originated outside the main planet-forming region and been captured into the Solar System’s gravity.

Other objects listed formed where they are now: Ceres is a dwarf planet in the asteroid belt between Mars and Jupiter, Eris is a Kuiper Belt Object believed to have formed in the outer Solar System like Pluto, and Planet X is a hypothetical distant planet not proposed as a captured body. Therefore, Pluto is the best-known candidate among these for a capture scenario.