Charles Poladian

Apr 11th 2018

The James Webb Technology: Letting Astronomers Peer into the Early Universe


NASA’s James Webb Space Telescope, heralded as the Hubble Space Telescope’s revolutionary successor, will transform our view of the universe when it begins its primary science mission. This incredible feat will result from the innovative work of a global team dedicated to unraveling the mysteries of the earliest galaxies and distant objects. The James Webb technology that will help us explore the universe includes a revolutionary primary mirror, a camera equipped with microshutters and infrared detectors capable of detecting the faintest objects in the galaxy.

A Mirror into the Early Universe

Perhaps the most impressive aspect of James Webb technology is the sheer size of some of its components. The telescope’s primary mirror is a slight misnomer because it’s actually a complex structure of 18 hexagonal segments assembled together that can unfold in space, according to NASA. Each mirror segment is made of beryllium, a durable and lightweight element. Combined, these 18 segments form a mirror that’s 6.5 meters (21 feet, 4 inches) across. For comparison, Hubble’s primary mirror measures 2.4 meters (7 feet, 10 inches).

The James Webb Space Telescope’s primary mirror will be the largest ever launched into space, NASA notes. Once in place, the mirror will collect an incredible amount of light, allowing its onboard suite of instruments to capture faint objects that can be further than 13 billion light-years away. Each segment has an actuator that lets researchers focus on distant galaxies and stars.

Researchers already have many observational candidates to test the new James Webb technology. One focus is GN-z11, a galaxy spotted by Hubble that’s 13.4 light-years away. According to NASA, GN-z11 is the farthest galaxy ever observed. The James Webb Space Telescope can provide new insights into this galaxy and discover other faint galaxies that formed just a few hundred million years after the Big Bang. With so many observation candidates, the telescope’s cameras come equipped with new technology that allows these instruments to observe multiple objects simultaneously.

Take a Picture

As any avid smartphone photographer knows, your eye is only as good as the camera’s shutter. By adjusting the shutter, you’re letting in the right amount of light to capture that perfect outdoor landscape or dimly lit dinner. Projecting outward, the same principles apply for capturing distant galaxies and objects in the universe. Unlike a smartphone camera, the James Webb Space Telescope is equipped with microshutters developed just for the telescope, NASA explains.

Microshutters give astronomers unprecedented control over what objects can be observed at any given moment. The microshutters are found on the telescope’s Near Infrared Spectrograph (NIRSpec) and measure just 100 by 200 microns, according to NASA. Equipped with more than 250,000 microshutters, the NIRSpec instrument can observe 100 objects simultaneously. Researchers can program the microshutter array to let only the light necessary into the NIRSpec instrument. This ability is especially important because the objects James Webb will be tasked to observe, including GN-z11 and similar galaxies, are so faint that it takes many hours of observation before an image can be formed.

The NIRSpec instrument can also help detect new exoplanets along with observing the faintest stars and galaxies, NASA explains. The Bright Object Time Series (BOTS) mode is ideal for observing the transits of exoplanets as they pass in front of distant stars.

The largest mirror launched into space, microshutters that can focus on 100 objects simultaneously and an instrument capable of observing distant objects and discovering exoplanets are just a few components of the innovative James Webb technology. A project of this scope and magnitude requires new ways of thinking to better understand the beginning of the universe — made possible by a team of passionate individuals willing to push the boundaries of science and technology.