Practice Tests
IELTS Reading (AC) Task 1 #185

A. The James Webb Space Telescope (JWST) is a large, infrared-optimised space telescope that represents the next great observatory for astronomy. Launched in 2021, it is the successor to the Hubble Space Telescope but is significantly larger and more powerful. Its primary mission is to peer deeper into the cosmos than ever before, to study the first galaxies that formed after the Big Bang, the birth of stars and planetary systems, and the atmospheres of exoplanets in search of potential signs of life.

B. One of the JWST''s key features is its massive primary mirror, which is 6.5 metres in diameter—nearly three times the size of Hubble''s. This large mirror, composed of 18 gold-coated hexagonal segments, gives the telescope exceptional light-gathering ability, allowing it to see faint and distant objects. To detect the faint infrared light from the early universe, the telescope must be kept extremely cold. It is positioned at a special point in space about 1.5 million kilometres from Earth and is protected by a five-layer sunshield the size of a tennis court, which blocks heat from the Sun, Earth, and Moon.

C. The JWST is designed to observe the universe primarily in the infrared part of the spectrum. This is crucial because the light from the very first stars and galaxies has been stretched by the expansion of the universe into longer, redder wavelengths, a phenomenon known as cosmological redshift. Infrared observation also allows the telescope to see through the clouds of cosmic dust that obscure the birthplaces of stars and planets.

D. The James Webb Space Telescope is one of the most complex and ambitious scientific projects ever undertaken. Its early images have already provided breathtaking and unprecedented views of the universe, revealing a wealth of new detail about cosmic structures and processes. It is expected to revolutionise our understanding of the universe''s origins and our place within it, driving astronomical discoveries for decades to come.