The US space agency NASA has released the first images from the James Webb Space Telescope (JWST), the most powerful ever in orbit . Using a system of lenses, filters and prisms to detect infrared signals invisible to the human eye, the telescope is able to look inside the atmosphere of exoplanets and observe some of the oldest galaxies in the universe.
The first composite image, collected in 12.5 hours, shows the clearest image to date of the early universe as it was 13 billion years ago. This is a fragment of SMACS 0723, where you can see the light of thousands of the oldest galaxies, colored in blue, orange and white tones. The light of some galaxies bends around others and after billions of years falls into the field of view of the telescope.
Experts say that this is not the limit: the telescope can see much further, so it is possible to see the Universe at its very beginning - as it was shortly after the Big Bang, which occurred about 13.8 billion years ago. According to scientists, the capabilities of "James Webb" are so superior to those of previous telescopes that its appearance is like opening a window after peering through a gap.
The telescope was launched in December from French Guiana on an Ariane 5 rocket. It now orbits the sun at a distance of 1.6 million kilometers from Earth, in a region of space called the second Lagrange point. It can stay here in a fixed position relative to the Earth and the Sun, and it needs a minimal amount of fuel to correct its course. The main Webb mirror has a width of more than 6.5 meters and consists of 18 gold-plated mirror segments. To obtain high-quality images, the structure must remain as stable as possible, so that it fluctuates by no more than 17 millionths of a millimeter.
Among the first JWST objects are the Karina Nebula, a kind of "celestial nursery" at a distance of about 7600 light, where huge, several times larger than the Sun, stars are formed; giant planet WASP-96 b outside the solar system; the South Rim Nebula, a cloud of gas with a dying star at its center, located 2,000 light-years from Earth; Stefan's Quintet is a compact group of galaxies discovered in 1877.
NASA estimates that Webb has enough fuel to operate in orbit for 20 years. Working alongside the Hubble and Spitzer telescopes, it can help scientists answer fundamental questions about the cosmos.