top of page

Satellite images

Satellite photography

Hubble Space Telescope (HST):

  1. Launch and Operation:

  • Launch Date: Hubble was launched into low Earth orbit in April 1990 aboard the Space Shuttle Discovery.

  • Location: It orbits the Earth at an altitude of about 547 kilometers (340 miles).

  • Service Missions: Hubble has been serviced and upgraded several times by space shuttle missions, extending its operational life and capabilities.

  1. Primary Mirrors and Instruments:

  • Primary Mirror: Hubble has a 2.4-meter (7.9-foot) diameter primary mirror.

  • Instruments: It is equipped with a suite of scientific instruments, including cameras and spectrographs, covering ultraviolet, visible, and near-infrared wavelengths.

  1. Observational Capabilities:

  • Wavelength Range: Hubble primarily observes in the ultraviolet, visible, and near-infrared parts of the spectrum.

  • Targets: It has observed a wide range of celestial objects, from planets within our Solar System to distant galaxies.

  1. Achievements:

  • Discoveries: Hubble has made numerous groundbreaking discoveries, including measuring the rate of expansion of the universe (Hubble's law), imaging exoplanets, and studying distant galaxies and black holes.

James Webb Space Telescope (JWST):

  1. Launch and Location:

  • Planned Launch: JWST is planned to be launched into orbit around the Sun-Earth Lagrange Point 2 (L2), which is about 1.5 million kilometers (0.93 million miles) from Earth.

  • Launch Date: As of my last update, JWST was scheduled for launch in December 2021 (dates may have changed, so please verify).

  • Stable Orbit: JWST will maintain a stable position relative to Earth as it orbits the Sun together with Earth.

  1. Primary Mirror and Instruments:

  • Primary Mirror: JWST has a much larger primary mirror than Hubble, spanning 6.5 meters (21.3 feet) in diameter. This larger mirror allows for higher resolution and sensitivity in the infrared spectrum.

  • Instruments: It is equipped with sophisticated infrared instruments, designed to study the universe in wavelengths ranging from 0.6 to 28 micrometers.

  1. Observational Capabilities:

  • Wavelength Range: JWST specializes in observing in the infrared spectrum, which is particularly useful for studying the formation of stars and galaxies, as well as detecting exoplanets.

  • Targets: JWST will focus on studying the early universe, the formation of stars and planetary systems, and the characterization of exoplanetary atmospheres.

  1. Technological Advances:

  • Sunshield: JWST is equipped with a large, five-layer sunshield to protect its sensitive instruments from heat and light from the Sun and Earth.

  • Cooling System: Its instruments and primary mirror are actively cooled to temperatures below 50 Kelvin (-223 degrees Celsius or -370 degrees Fahrenheit) to reduce infrared emissions that could interfere with its observations.

Comparison Summary:

  • Primary Functionality: Hubble observes primarily in the ultraviolet, visible, and near-infrared, while JWST specializes in the infrared spectrum.

  • Primary Mirror Size: Hubble has a 2.4-meter mirror, whereas JWST boasts a larger 6.5-meter mirror.

  • Observational Location: Hubble orbits Earth, while JWST will orbit the Sun-Earth L2 point.

  • Scientific Objectives: Hubble has provided a wealth of knowledge across a broad range of astronomical topics, while JWST aims to delve deeper into the early universe, star formation, and exoplanetary studies, focusing heavily on the infrared universe.

Both telescopes have significantly advanced our understanding of the cosmos and continue to shape our view of the universe in complementary ways, from the nearby Solar System to the distant reaches of space and time.

1 view0 comments

Recent Posts

See All


bottom of page