The James Webb Space Telescope is the largest, most powerful space telescope ever built. It will allow scientists to look at what our universe was like about 200 million years after the Big Bang. The telescope will be able to capture images of some of the first galaxies ever formed.
- To search for light from the first stars and galaxies that formed in the universe after the Big Bang
- To study galaxy formation and evolution
- To understand star formation and planet formation
- To study planetary systems and the origins of life
It will also be able to observe objects in our solar system from Mars outward, look inside dust clouds to see where new stars and planets are forming, and examine the atmospheres of planets orbiting other stars.
The Webb telescope is as tall as a 3-story building and as long as a tennis court! It is so big that it has to fold origami-style to fit inside the rocket to launch. The telescope will unfold, sun-shield first, once in space.
The James Webb Telescope orbits the Sun near the second Lagrange point (L2) of the Sun-Earth system, which is 930,000 mi farther from the Sun than the Earth’s orbit, and about four times farther than the Moon’s orbit. Normally an object circling the Sun farther out than Earth would take longer than one year to complete its orbit.
But near the L2 point, the combined gravitational pull of the Earth and the Sun allows a spacecraft to orbit the Sun at the same time that it takes the Earth. Staying close to Earth allows data rates to be much faster for a given size of the antenna. The telescope is named after James E. Webb, who was the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and much of the Apollo programs.
The James Webb Space Telescope will use its infrared cameras to see through dust in our universe. Stars and planets form inside those dust clouds, so peeking inside could lead to exciting new discoveries! It will also be able to see objects (like the first galaxies) that are so far away that the expansion of the universe has made their light shift from visible to infrared!
Webb has a sun-shield to protect its instruments and mirrors. The telescope’s sun-shield is about the size of a tennis court. The temperature difference between the sun-facing and shaded sides of the telescope is more than 600 degrees Fahrenheit.
The gold-coated mirrors help them reflect infrared light. The larger the mirrors the more the telescope can see but these are limited by what can fit into the spaceship. Engineers gave the Webb telescope 18 smaller mirrors that fit together like a puzzle. The mirrors fold up inside the rocket, then unfold to form one large mirror in orbit. It was launched December 25, 2021, on an ESA Ariane 5 rocket from Kourou, French Guiana, and is intended to succeed the Hubble Space Telescope as NASA’s flagship mission in astrophysics.
- Near-Infrared Camera, or NIRCam – provided by the University of Arizona
- Near-Infrared Spectrograph, or NIRSpec – provided by ESA, with components provided by NASA/GSFC.
- Mid-Infrared Instrument, or MIRI – provided by the European Consortium with the European Space Agency (ESA), and by the NASA Jet Propulsion Laboratory (JPL)
- Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph , or FGS/NIRISS- provided by the Canadian Space Agency
The telescope was released from the rocket’s upper stage 27 minutes after launch, which NASA described as “flawless” and “perfect”. As of January 24, 2022, the sun-shield, mirrors, and other components were fully unfolded to their operational configuration.
The spacecraft entered orbit at its destination, and all instruments were successfully powered on. On February 3, 2022, NASA tweeted that the telescope detected its first photons, and on February 11, 2022, NASA announced the telescope had almost completed phase 1 of alignment.
Every segment of its primary mirror has located, imaged, and approximately centered the target star HD 84406. Several weeks are still needed for the telescope to cool to its operational temperature. Mirror alignment and focusing and final testing and calibration will take about five months, potentially including the first formal images, before planned research begins.
The James Webb Space Telescope will help to study the atmospheres of exoplanets. Could the atmospheres of some exoplanets hold the building blocks for life? We will find out soon! Follow the progress at James Webb Space Telescope.