Answer to Question #306255 in Astronomy | Astrophysics for Rohan

Question

Why is it important to position the JWST behind the Earth?

Answer 1

Sun is a powerful source of visible, infrared and ultraviolet emission. Therefore, the Earth is a kind of shield for JWST to prevent powerful illumination from the Sun. Therefore, JWST will be able to receive quite small amount of infrared radiation from celestial objects. For JWST to stay always behind the Earth is is important to place it at Sun–Earth L₂ orbit, because this is a point of equilibrium for small-mass objectunder the influence of two massive orbiting bodies.