What is the transit method of finding extrasolar planets?
A) measuring the spectrum of the star for a periodic variation in its Doppler shift
B) monitoring a star to detect periodic dips in its brightness from the planet passing behind the star
C) monitoring a star to detect periodic dips in its brightness from the planet passing in front of the star
D) observing a star during the rare occasion of another star passing directly in front of it; slight changes in how the light is bent by gravity can indicate the presence of planets around the closer star
Question 2
The total number of stars in the observable universe is about ________.
A) the same as the number of grains of sand on all the beaches on Earth
B) the same as the number of grains of sand in a school sandbox
C) 100 billion
D) the same as the number of atoms that make up the Earth