The Ultimate Time Machine

Hubble's precocious replacement, the James Webb Space Telescope, will enable a flood of new discoveries.

The Hubble Space Telescope has been a spectacular success, revolutionizing our knowledge of outer space. For 20 years, both astronomers and the public have been amazed by a series of measurements and truly beautiful images, from black holes to the birth of planets.

Yet by modern standards, Hubble is a somewhat limited telescope. Only through a series of space shuttle visits have we been able to improve its performance, and many astronomers still feel a twinge of embarrassment about the problems with the mirror in the early 90s (fortunately, a quick fix was possible).

The James Webb Space Telescope (JWST) is Hubble’s successor. Now scheduled to fly in 2014, it constitutes a quantum leap in performance. A light-collecting area seven times greater than Hubble's and a suite of new cameras and detectors will enable us to see the light from the very first stars and galaxies – structures that formed almost 13 billion years ago. Think of it as the ultimate time machine.

A contribution of $150 million of Canadian taxpayers’ money will help make all of this possible. Guided by the Canadian Space Agency, Canadian astronomers have collaborated with industry, to develop two vital components of the JWST.

As anyone who has tried pointing a telescope by hand knows, finding what you want to look at and then keeping the telescope steady is tough. The same thing applies to the JWST. But every time someone points the JWST, Canadian know-how will leap into action. We’re providing fine guidance sensors, a technology Canada is world renowned for, which can detect a difference in angle equivalent to the width of a hair from four kilometres away.

Canada is a world leader in the incredibly exciting new field of planet imaging, and the second piece of the technology package we’re contributing is the Tunable Filter Imager (TFI). The TFI is an ingenious infrared camera that can block the light from a star, revealing the planets around it. So along with the first stars and galaxies, the JWST will take pictures of planets around nearby stars.

These planets are at an enormous distance from the earth, much, much farther away than Pluto, and their parent stars are around 10,000,000,000 times brighter than them. Finding them is like finding a glow-worm in front of 100 of the brightest lighthouses in the world. The fact that we have technology to see them is astonishing.

But while technology is critical, what really makes all of this possible is the knowledge and management skills of certain individuals, in particular two Canadian astronomers: Dr. John Hutchings of the Herzberg Institute of Astrophysics in Victoria, B.C., and Dr. René Doyon of the Université de Montreal.

Hutchings is the lead Canadian project scientist. He is a veteran of decades of space projects, and his skills are in demand across the globe. Doyon is the principle investigator on the Tunable Filter Imager. The inaugural recipient of the mid-career award from the Canadian Astronomical Society, he is widely recognized as a world leader in the imaging of extrasolar planets.

These guys are good. Canadians can justifiably be proud of them. But for all the cutting-edge technology going into the project – and there are already plenty of industrial “spin-offs” – it’s the anticipation of new discoveries that stokes the imagination.

I’ve already mentioned seeing the first stars and galaxies and imaging planets around other stars; what else can we expect? We’ll observe the structure of galaxies, and by building up a series of images, like creating a family album covering pre-school to retirement, we’ll better understand how galaxies form and evolve.

We’ll also observe stars in the process of forming. Stars and planets actually form at the same time from a giant cloud of gas and dust. Gravity and a tiny amount of initial motion eventually lead to a disk of material, with the star emerging from the centre. The planets “rain out” of the material in the disk at the same time. It all takes thousands to millions of years, but as we did with galaxies, we’ll take snapshots of different systems to figure out how it all happens.

I can’t begin to describe how awe-inspiring the images will be, so I won’t try. But jaws will drop.

The excitement growing behind the JWST is infectious. You can feel it whenever astronomers talk about the coming discoveries. Don’t get me wrong – it will be sad to finally turn off Hubble. But if Hubble opened a window on new discoveries, the JWST will bust open the barn doors.