Question

The discovery of hot Jupiters led scientists to reconsider the nebular theory. Which of the following best explains why the nebular theory (as it stood before the discoveries of extrasolar planets) had not predicted the existence of hot Jupiters?

A. Hot Jupiters are located very close to their parent stars.

B. The nebular theory only applies to our solar system.

C. Hot Jupiters are composed of unique materials.

D. The nebular theory was developed after the discovery of hot Jupiters.

Answer 1

The nebular theory did not predict hot Jupiters because it assumed giant planets could only form far from their stars, where it's cold enough for water ice to condense. The presence of hot Jupiters close to stars suggests they formed further out and then migrated inward.

Step-by-step explanation:

The discovery of hot Jupiters challenged our previous understanding based on the nebular theory. The traditional model assumed that giant planets would form far from their stars, where temperatures would allow for the condensation of water ice. This is crucial for the formation of such large planets.

However, hot Jupiters are found incredibly close to their stars, a region too hot for water ice to exist, suggesting that they could not have formed there.

To reconcile this, we consider that these planets may have formed further out, where conditions were suitable, and then migrated inward. This leads us to believe that planet-forming models must allow for planet migration or changes in orbits post-formation, as supported by most recent research.