We have liftoff

| December 26, 2021

A “game changing” new telescope has blasted into space to begin a lonely 1.5-million-kilometre orbit around the Sun to provide a clearer view of the ever-expanding universe.

The James Webb Space Telescope (JWST) was named after the NASA scientist who led the Apollo moon landings and called for a space telescope in the 1960s.  It has been developed by NASA with contributions from the European Space Agency (ESA) and the Canadian Space Agency (CSA) since planning began in 1996.

Dwarfing the Hubble’s 2.4 metre mirror, the JWST’s 6.5 metre mirror makes it the largest telescope ever to be launched into space.  Although the project has been dogged by delays, technical difficulties and cost-overruns, hopes are high that the project will now bear fruit for significant scientific discoveries.

It will be used by astronomers around the world, including University of Queensland researchers, to observe asteroids and newborn planets, as well as black holes in distant galaxies.  As it is able to observe low-frequency infrared emissions, it should be able to view some of the most distant events and objects in the universe, including the formation of the first galaxies, and generate detailed atmospheric profiles of potentially habitable exoplanets.

The telescope must be kept cold to observe infrared without interference, and so rather than sit in Earth orbit, the massive telescope will be deployed near the Sun–Earth L2 Lagrange point, about 1.5 million kilometres (930,000 mi) from Earth – 3.9 times further than the moon.

There are five Lagrange Points where the opposing gravity from the sun and Earth balance the orbital motion of a satellite to keep it in a stable position relative to Earth with minimal energy required for micro-course corrections.  The position also helps the telescope radiate heat from the sun away from its delicate components.

UQ astrophysicist Dr Benjamin Pope said he’s excited by the capabilities of the JWST, widely considered as the successor to the famed Hubble Space Telescope, which launched in 1990. However, unlike the Hubble, any physical faults on the telescope will be far out of reach of mankind’s ability to reach and fix by hand.

“The JWST will go dramatically beyond what any telescope has been able to do – it will see some of the first stars in the universe, billions of light years away,” Dr Pope said.

The more distant an object is, the younger it appears, as its light has taken longer to reach human observers. Because the universe is expanding, light becomes red-shifted as it travels through space, and objects at extreme distances are therefore easier to see if viewed in the infrared, as they are less impeded by cosmic dust clouds. JWST’s infrared capabilities could let it see back in time to the first galaxies forming just a few hundred million years after the Big Bang.

Furthermore, once it achieves its planned position in late January 2022, the telescope will allow the analysis of exoplanet atmospheres, potentially proving that life exists on other worlds by detecting oxygen as well as water.

“By looking at exoplanets as they transit, it will measure their atmospheric composition and detect water and other molecules that could indicate planets capable of sustaining life.

“It changes the game on how we observe planets, stars, asteroids, and the universe around us.”

After more than a decade of delays, on December 24 the telescope was launched on a European Ariane 5 rocket from French Guiana, bringing astronomers closer to distant galaxies than ever before.  Originally slated to cost $500 million, its total cost of $10 billion means that a successful mission is vital for the future of large space observation projects.

“One of the main benefits of a space telescope such as the JWST is that it overcomes one of the biggest problems facing astronomers – the atmosphere blocking their view of the wider universe,” Dr Pope said.

“Such a powerful space telescope will put us on the doorstep of some incredible discoveries.”

Dr Pope will be involved in several observation projects, including the kernel phase project, observing distant and hard-to-see stars and planets, and on an aperture masking project to study planets at the moment they form around stars, and on methods to observe asteroids and dwarf planets with greater clarity than ever before.

“One project will use the JWST to study how brown dwarfs form, and since I’ve worked on a similar project for my Honours thesis using data from the HST, my role will be using the very same algorithm to analyse data from the JWST regarding these brown dwarfs,” Dr Pope said.

“Another project will observe the most important asteroids – the only problem is they’re too bright to observe, and images are washed out.

“To deal with this, we’ve developed methods to make it easier to observe these ‘too-bright’ stars, that involves a high dynamic range image processing mode – like you’d use on your phone camera to bring out dark shadows and bright highlights.”

UQ Associate Professor Holger Baumgardt will use the JWST for a series of observation projects aimed at identifying and studying black holes in distant galaxies.

“Specifically, we’ll be searching for supermassive black holes in the centres of nearby galaxies,” Dr Baumgardt said.

“Our aim is to understand the relationship between the mass of both black holes and the galaxies that host them and learn how these supermassive black holes formed.”

Equipped with the far-reaching capabilities of the JWST, Dr Pope said the future of astronomy looks bright, with answers to some of astronomy’s most important questions within reach.

“JWST will give us a clearer picture of the origins of our own Solar System, and our best ever glimpses of the other weird and wonderful systems of planets in the Galaxy.”

While the Hubble has been in Orbit for three decades, the JWST has a designed life of just 10 years, due to the limited supply of propellant it carries for micro-adjustments to maintain its distant position.