Difference between James Webb Space Telescope and Hubble Space Telescope

The James Webb Space Telescope (JWST) and the Hubble Space Telescope (HST) are two significant astronomical observatories, but they have different design, capabilities, and scientific goals. Here's a comparison between the James Webb Space Telescope and the Hubble Space Telescope!

James Webb Space Telescope (JWST)

1. Launch and Location:

   • The JWST was launched into space on 25 December 2021 and positioned at the second Lagrange point (L2), which is located approximately 1.5 million kilometers (about 930,000 miles) away from Earth. This location provides a stable environment and allows the telescope to observe the universe in the infrared part of the electromagnetic spectrum.

2. Primary Objective:

   • The primary scientific goal of the JWST is to observe the universe in the infrared wavelength range, which Hubble cannot do as effectively. It aims to study the early universe, the formation of stars and galaxies, and the atmospheres of exoplanets, among other objectives.

3. Infrared Capabilities:

   • The JWST is equipped with specialized instruments and a large, segmented primary mirror that can capture infrared radiation. This allows it to peer through dust clouds, study cool objects, and detect the light from the first galaxies that formed in the early universe.

4. Size and Instruments:

   • The JWST is significantly larger than Hubble, with a primary mirror that is 6.5 meters (21.3 feet) in diameter. It carries a suite of scientific instruments designed for infrared observations.

5. Sunshield:

   • The JWST has a five-layer sunshield that keeps its instruments extremely cold. This is crucial for its infrared observations, as the instruments need to be colder than the objects they are observing.

Hubble Space Telescope (HST)

1. Location:

   • Hubble has been in orbit around Earth since its launch in 1990. It orbits at a relatively low altitude above Earth's atmosphere.

2. Primary Objective:

   • Hubble's primary goal is to observe the universe across a wide range of wavelengths, from ultraviolet to visible and near-infrared. It has provided valuable data on distant galaxies, nebulae, stars, and planets.

3. Visible and Ultraviolet Capabilities:

   • Hubble is optimized for visible and ultraviolet observations, making it ideal for capturing detailed images of celestial objects and phenomena in these wavelengths.

4. Size and Instruments:

   • Hubble has a 2.4-meter (7.9-foot) primary mirror and a range of scientific instruments, including cameras, spectrographs, and detectors. These instruments have been upgraded over the years to enhance its capabilities.

5. Repair and Maintenance:

   • Unlike the JWST, Hubble has been serviced by astronauts on several occasions. These servicing missions allowed for instrument repairs and upgrades, extending its operational lifespan.