[2026] PTE Academic Reading - Multiple Choice, Multiple Answers

Launched in December 2021, the James Webb Space Telescope (JWST) represents a monumental leap in infrared astronomy.Unlike its predecessor, the Hubble Space Telescope, which primarily observes visible and ultraviolet light, JWST is designed to detect faint infrared signals.This capability allows astronomers to peer through dense clouds of cosmic dust that obscure the view of visible-light telescopes, revealing the birth of new stars and planetary systems.

One of the primary scientific goals of the JWST is to study the very first galaxies that formed in the early universe, shortly after the Big Bang.Because the universe is expanding, the light from these distant galaxies is stretched into longer, redder wavelengths by the time it reaches Earth, a phenomenon known as cosmological redshift.By capturing this highly redshifted infrared light, JWST functions essentially as a time machine, looking back over 13.5 billion years into the past.

To function properly, the telescope's sensitive instruments must be kept incredibly cold, at temperatures below 50 Kelvin.To achieve this, JWST is equipped with a tennis-court-sized sunshield that blocks heat and light from the Sun, Earth, and Moon.Additionally, it operates from a specific location in space called the second Lagrange point (L2), which allows the telescope to stay in a fixed position relative to the Earth and Sun, maintaining a stable thermal environment.