Halley's Comet has an orbital period of 76 years. What is the average distance of Halley's Comet from the sun? a. 51 AU b.) 18 AU c. 114AU d. 660 AU e. 38 AU

Option (b) 18 AU

Explanation:

Data provided:

Orbital period = 76 years

Now,

From the Kepler's third law

we have the relation

a³ = T²

here,

T is the orbital period in years

and,

a is the average distance from the sun (in AU)

on substituting the value in the above relation, we get

a³ = 76²

or

a³ = 5776

or

a = ∛5776

or

a = 17.94 ≈ 18 AU

hence, the correct answer is option (b) 18 AU