Scientists are observing and recording data for two different planets, planet X and planet Y. Each planet orbits a different star. The planets have the same mass. The scientists record the following data.

Question

Star X – Planet X Star Y – Planet Y
Distance (millions of kilometers) 100 100
Orbital period of the planet
(Earth days) 390 260

Which of the following statements is most likely true?
A.
The star close to planet Y has more mass.
B.
The star close to planet Y has less mass.
C.
The star close to planet Y is hotter.
D.
The star close to planet Y is cooler.

Answer 1

A. The star close to planet Y has more mass.

This can be inferred because the orbital period of planet Y is shorter than that of planet X, indicating that the gravitational pull of the star close to planet Y is stronger. This suggests that the star close to planet Y is more massive than the star close to planet X.