The Saros cycle
A) was used in ancient times to predict eclipses.
B) is 18 years, 11 days long.
C) accounts for the tides seen on Earth.
D) was used in ancient times to predict eclipses and is 18 years and 11 days long,
E) None of the other choices are correct.

Question

The Saros cycle
A) was used in ancient times to predict eclipses. 
B) is 18 years, 11 days long. 
C) accounts for the tides seen on Earth. 
D) was used in ancient times to predict eclipses and is 18 years and 11 days long, 
E) None of the other choices are correct.

Quizplus · Accepted Answer

The Saros cycle was used in ancient times to predict eclipses and is 18 years and 11 11ec0318_88e6_ace6_938b_f7602194c5bf_TBX8927_11 days long. It is a period of about 223 synodic months (the period it takes for the Moon to return to the same phase). By knowing the length of a Saros cycle, one can predict when eclipses will occur, as eclipses tend to occur in cycles separated by Saros periods. The Saros cycle has nothing to do with tides on Earth.

The Saros Cycle