A planet's density can be measured by combining
A)Doppler and astrometric observations.
B)Doppler and transit observations.
C)spectral observations of the planet's atmosphere.
D)any method that measures the gravitational tug of the planet on the star.
E)direct imaging from the new generation of space telescopes.

Question

Quizplus · Accepted Answer

Doppler observations can give us information about the planet's mass, while transit observations can give us the planet's radius. Combining these two measurements allows us to calculate the planet's density. The other options listed may be used for other measurements, but are not the most effective for measuring a planet's density.

A Planet's Density Can Be Measured by Combining