From the Earth, a dark purple triangle begins, slowly enlarging toward the right to cover the area where a small illustration of the James Webb Space Telescope appears and a long, wavy multicolored line. Graphic titled “Redshifted Light from Distant Galaxies.”Ī small full-color illustration of the Earth, which is labeled in white text, appears at far left. Observation of these early days in the universe’s history will shed light on perplexing questions of dark matter and energy, black holes, galaxy evolution over time, what the first stars were like, and how we arrived at the universe we experience today. Through a process called cosmological redshifting, light is stretched as the universe expands, so light from stars that is emitted in shorter ultraviolet and visible wavelengths is stretched to the longer wavelengths of infrared light. In this way, Webb will reveal a “hidden” universe of star and planet formation that is literally not visible.įinally, infrared light holds clues to many mysteries from the beginning of everything, the first stars and galaxies in the early universe, after the big bang. Low-energy brown dwarfs and young protostars forming in the midst of a nebula are among the difficult-to-observe cosmic objects that Webb can study. The longer wavelengths of infrared light slip past dust more easily, and therefore instruments that detect infrared light-like those on Webb-are able to see the objects that emitted that light inside a dusty cloud. Visible light’s short, tight wavelengths are prone to bouncing off dust particles, making it hard for visible light to escape from a dense nebula or protoplanetary cloud of gas and dust. Humans perceive this as heat, while some other animals, like snakes, are able to “see” infrared energy. Some bodies of matter that are cool and do not emit much energy or visible brightness, like people or a young planet, still radiate in the infrared. Infrared light is important to astronomy in three major ways.įirst, some objects are just better observed in infrared wavelengths. The Spitzer Space Telescope has a wavelength range of 3,000 to 160,000 nanometers, corresponding to the right half of the Infrared segment. The James Webb Space Telescope has a wavelength range of 600 to 28,500 nanometers, corresponding to a sliver of red visible light and the left half of the Infrared segment. From left to right: The Hubble Space Telescope has a wavelength range of 90 to 2,500 nanometers, corresponding to the right-most portion of the Ultraviolet segment, all of the Visible, and the left-most sliver of the Infrared segment. The wave pattern above Radio is more extended (longest wavelength).īelow the wavelength bar are line sketches of three telescopes, labeled with the telescope name and wavelength range. The wave pattern above Gamma is tightest (shortest wavelength). The wavelengths increase from left to right. The sine wave patterns are oriented vertically. The Visible segment is rainbow, from purple on the left to red on the right.Ībove each segment is a sine wave pattern indicating the relative wavelength of the band. The Infrared segments is shades of red and orange. The Ultraviolet segment is various shades of purple. Gamma, X-ray, Microwave, and Radio segments are all colored in shades of gray. From left to right these are: Gamma, X-Ray, Ultraviolet, Visible, Infrared, Microwave, and Radio. The diagram includes a horizontal bar consisting of seven labeled segments representing seven different bands of the electromagnetic spectrum. Infographic titled “Electomagnetic Spectrum” comparing the wavelengths of light that can be detected by the Hubble, Webb, and Spitzer space telescopes.
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