Process of Science: Name a testable hypothesis of nebular theory that was shown to be false in observations of extrasolar planets. Must we throw out the theory and start from scratch, i.e

, is the observation completely inconsistent with a nebular formation?


At face value, the nebular theory predicts that massive, gas rich planets should form far from the star beyond the snowline. However, astronomers have discovered a large number of large planets that orbit close to their stars ("hot Jupiters"). This is partially because they are easiest to find, but still their existence was surprising and requires that the nebular theory be discarded or modified. Because it explains so many other facts, astronomers have preferred to modify the theory and have invoked planetary migration as a means to move massive planets that formed far from the star to much closer in.

Physics & Space Science

You might also like to view...

A capacitor in a single-loop RC circuit is charged to 85% of its final potential difference in 2.4 s. What is the time constant for this circuit?

a. 1.5 s b. 1.3 s c. 1.7 s d. 1.9 s e. 2.9 s

Physics & Space Science

A 100-N force has a horizontal component of 80 N and a vertical component of 60 N. The force is applied to a cart on a level frictionless floor. The cart starts from rest and moves 2.0 m horizontally along the floor due to this force

What is the cart's final kinetic energy? A) 160 J B) zero C) 120 J D) 200 J

Physics & Space Science

For safety in climbing, a mountaineer uses a 50-m long nylon rope that is 1.0 cm in diameter. When supporting a 90-kg climber, the rope elongates 1.6 m. Find the Young's modulus for the rope material.

What will be an ideal response?

Physics & Space Science

If you carry a heavy bag of groceries and bang your hand against the wall, the concept that best explains why your hand hurts is

A) inertia. B) gravity. C) resistance. D) none of the above

Physics & Space Science