In 2021 NASA plans to launch the James Webb Space Telescope, the successor to the Hubble Space Telescope. The Hubble Space Telescope was launched in 1990 with the aim of gathering light from cosmic objects so that we can better understand the universe we call home.
Since it’s launch, the telescope has provided scientists and space enthusiasts with a dazzling array of images of the cosmos. These images range from space objects close to home like The Moon, as well as galaxies, supernovas, and nebulas far beyond us.
But like all cutting edge technology, it eventually becomes out of date and is surpassed with more advanced technology. This isn’t to say The Hubble Telescope is a failing piece of technology, quite the opposite. The Hubble Telescope is still working great and still making discoveries all the time, for example in 2017 Hubble discovered a stratosphere on a huge exoplanet, captured ultrabright galaxies and observed the farthest known active comet. It is expected that the telescope will continue to capture the cosmos beyond the release of The James Webb Telescope, which is intended to complement and extend these discoveries.
Four Science Goals For The James Webb Space Telescope
NASA’s science goals for the groundbreaking telescope can be split into four areas. The aim behind these areas is to answer some key questions about our universe and its origins.
First Light and Reionization.
One bold aim of the JWST is to capture the first light of the universe. The first light refers to a point in the Universe’s infancy when the universe was an ocean of different particles and light wasn’t visible until the universe began to cool. Using infrared, the telescope will essentially be able to peer back in time 13.5 billion years.
Reionization refers to the “epoch of reionization”, a time just after the first stars had formed. The name comes from how in this early universe, hydrogen was ionized by radiation from the first stars. Capturing evidence of this is another key aim of JWST.
Cosmic microwave background radiation (CMB) A remnant from an early stage of the universe
Assembly of Galaxies
Galaxies are the cosmic shapeshifters of the Universe, they can change shape over time, resulting in what we see today. The shape is changed because of how matter gathers on large scales. JWST aims to look back at the Universe’s early galaxies to understand how this process takes place.
The Birth of Stars and Proplanetary Systems
Hubble image of a new star being born | credit: NASA
JWST’s new technological capabilities really become obvious with this one. The new telescope will be able to see through clouds of dust that have previously been obstructed and closed off to the Hubble Telescope.
Planetary Systems and Origins of Life
The aim here is to learn more about the atmospheres of extrasolar planets and maybe even find evidence of life elsewhere, and the building blocks of that life. This could lead to some huge breakthroughs in astronomy and astrobiology.
Cosmic Wow Factor
The JWST’s primary mirror is made up of 18 hexagonal mirror segments of gold coated beryllium. The diameter of the mirror is a whopping 6.5 meters, much larger than Hubble’s 2.4 meters, and the largest mirror sent to space. Having such a large mirror will allow the telescope to collect more light from the objects it observes, meaning it will be able to see with greater sensitivity than the Hubble telescope.