The James Webb Space Telescope (JWST) is a next-generation space observatory developed by NASA, in collaboration with the European Space Agency (ESA) and the Canadian Space Agency (CSA). It is designed to explore the universe in the infrared spectrum, allowing it to see farther into space than previous telescopes like the Hubble Space Telescope (HST).
Key Differences Between the JWST and Hubble:
- Wavelength Range:
- JWST: Primarily observes in the infrared spectrum (0.6 to 28 microns), which allows it to see through dust clouds and observe objects that are too faint or distant for visible light telescopes.
- Hubble: Observes mainly in the ultraviolet (UV), visible, and near-infrared wavelengths, which limits its ability to observe certain objects or phenomena, particularly in the early universe.
- Location:
- JWST: Located at the second Lagrange point (L2), about 1.5 million kilometers (approximately 1 million miles) from Earth. This position offers a stable environment, reducing interference from Earth’s atmosphere and thermal radiation.
- Hubble: Orbiting Earth at an altitude of about 547 km (340 miles), meaning it operates in a low-Earth orbit, and can be serviced by astronauts.
- Mirror Size:
- JWST: Has a large, segmented primary mirror that measures 6.5 meters (21.3 feet) in diameter, significantly larger than Hubble’s mirror. This allows JWST to gather more light, improving its ability to detect faint objects in the distant universe.
- Hubble: Has a smaller primary mirror, measuring 2.4 meters (7.9 feet) in diameter, which limits its light-gathering capability compared to JWST.
- Scientific Goals:
- JWST: Primarily aims to study the early universe, exoplanets, star and galaxy formation, and the atmospheres of distant planets, especially those in the habitable zone. Its infrared capabilities enable it to observe the first galaxies formed after the Big Bang and look inside dense molecular clouds where stars and planetary systems are born.
- Hubble: Focuses more on visible and ultraviolet observations, helping to understand the structure and dynamics of galaxies, the formation of stars, and the nature of black holes. While it also observed distant galaxies and the early universe, its main strength is in optical and ultraviolet astronomy.
- Technological Advances:
- JWST: Equipped with advanced instruments like a highly sensitive infrared camera, a spectrometer, and a fine guidance system. It also features a sunshield the size of a tennis court, protecting the telescope from heat and light from the Sun and Earth.
- Hubble: While it also has remarkable instruments like cameras and spectrometers, its technology is now over three decades old, and it primarily operates in the optical and ultraviolet bands.