The orbiting observatory, which is designed to be about 100 times more powerful than Hubble, has a gigantic golden mirror measuring just over 21ft across that is made up of 18 individual hexagonal segments that can fold up and unfold.
This is because light from distant objects is stretched out by the expansion of our universe - an effect known as redshift - pushing the light out of the visible range and into infrared. This is because of the time it takes light to travel from the object to us The further away an object is, the further back in time we are looking. Webb's infrared capabilities allow it to 'see back in time' to the Big Bang, which happened 13.8 billion years ago. Light waves move extremely fast, about 186,000 miles (300,000 km) per second, every second. Infrared light can penetrate these obstacles. Its ability to view the universe in longer wavelength infrared light is also important because recently formed stars and planets are often hidden behind masses of dust that absorb visible light. Since the Webb telescope has a much bigger mirror than Hubble, it can look further back in time. The size of a telescope's mirror area determines its sensitivity, or how much detail it can see. With James Webb's larger mirror, it will be able to see almost the whole way back to the beginning of the universe, more than 13.5 billion years ago. To see objects so faint and far away, the telescope needs a giant mirror to collect the light. Therefore, we see objects not as they are now but as they were at the time when they released the light that has travelled for billions of years across the universe to reach us. It takes time for the light the telescope is receiving to travel through space.
When a telescope looks further away, it is also looking back in time. What does it mean to be looking at the distant universe? Webb also doesn't orbit Earth, like its predecessor Hubble does, but rather orbits the sun 1 million miles (1.5 million km) from our planet at what is called the second Lagrange point or L2. Only telescopes that can detect infrared light can see the faintest light from distant galaxies and other objects, and therefore make images of them, which is what Webb is capable of doing. This means that by the time the light reaches Earth, that stretching process has transformed short wavelengths of visible and ultraviolet light into the longer wavelengths of infrared light.
This is what makes Webb special, because it detects infrared light at longer wavelengths than can be sensed by our eyes.Įssentially, as light from the universe's most distant galaxies travels through space, it is stretched by the expansion of space. Unlike large observatories on the ground, Webb has been blasted into the cosmos so that it can observe distant objects without having its view disrupted by Earth's atmosphere, which blocks wavelengths of light in the red to mid-infrared spectrum. James Webb is basically a huge telescope in space. MailOnline has spoken to a number of astronomers to get the answers to all your big questions. It is hoped the $10 billion (£7.4 billion) telescope will also observe the very first stars to shine, detect habitable planets in far-away galaxies and peer back in time to within 100-200 million years of the Big Bang.īut apart from being dazzling, beautiful images of galaxies, nebulae and even the atmospheric spectrum of distant world WASP-96 b, what are the significance of the images to scientists, members of the public and humanity in general? What is even more exciting, however, is that astronomers say this is just 'the tip of the iceberg'. James Webb captured an unprecedented look at a 'stellar nursery', a dying star cloaked by dust and a 'cosmic dance' between a group of galaxies, along with hints of water vapor in the atmosphere of a remote exoplanet. Spectacular and groundbreaking snapshots of the early cosmos gripped the world earlier this week when NASA released the first images from its new super space telescope.
0 kommentar(er)
