# Explain various indirect methods for measuring large distances?

Explain various indirect methods for measuring large distances? 1. The method of parallax

Heliocentric parallax:

In its simplest form: two observations

of heavenly bodies taken after 6 months when earth is its orbital major axis (D) apart. The angle θ is the difference in the angle between two observations Since D << d

D = θd

=> d = D/θ

Thus distance of the heavenly body is calculated.

2. Method of echo or reflection

A laser is directed on the heavenly body and the time taken by the signal to return is noted and then using the following formula distance is calculated.

Let distance of the heavenly body = d

Velocity of the light = c

T = Time taken by the signal to return

c = 2D/T

3. The standard candle method:

Nearer objects are brighter and distance objects are fainter. Thus knowing the brightness of an object placed at a certain distance we can compute the distance of the object that is kept far away. It is one of the most important methods for determination of stellar distances.

• 1
What are you looking for?