Author Question: Process of Science: Name a testable hypothesis of nebular theory that was shown to be false in ... (Read 89 times)

Engineer · **on:** Jul 27, 2018

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?

Question 2

Describe two methods that have already been used to study extrasolar planets, and which one gives us the most information.

What will be an ideal response?

kkenney · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

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.

Answer to Question 2

Most have been detected by the Doppler shifts they induce in the motion of their home stars, with the periodicity of these shifts telling us their periods. But in the cases where the planet transits its sun, the timing of this light loss gives us the actual masses, sizes, and even densities of the transiting planets.