The 'Cosmic Cliffs' of the Carina Nebula is seen in an image divided horizontally by an undulating line between a cloudscape forming a nebula along the bottom portion and a comparatively clear upper portion, with data from NASA's James Webb Space Telescope, released July 12.NASA/Reuters
The early 1600s saw the invention of the first telescopes. Galileo is most famous among the first scientists who turned this new tool skyward. It was the early decades of the Scientific Revolution, and new views of the universe propelled a litany of discoveries.
Over centuries, telescopes continually advanced, from hand-held to mountaintop. In 1990, the Hubble Space Telescope was launched into orbit 600 kilometres above the Earth. It was at first out of focus, but once repaired the optical telescope started to unveil a bounty. A landmark image arrived in 1996: the first Hubble Deep Field revealed a “bewildering variety” of primordial galaxies.
During Hubble’s initial years in orbit, work began on a planned successor, a much more powerful telescope to be stationed much further away. The result, at a cost of US$10-billion and the work of some 20,000 people, is the James Webb Space Telescope, led by NASA with assists from Europe and Canada.
Its mission is to capture the light of ancient galaxies with a clearer eye than ever before and, relatively closer to home, hunt for elements of life on Earth-like planets. The Webb launched Dec. 25 and, after a month-long journey to a spot 1.5-million kilometres away, the first amazing images were published to widespread awe and wonder this week.
In a dauntingly complicated project where the number of things that could have gone wrong is almost too long to list, the Webb has immediately proved its technical potential. The most exciting thing is that this is just the start. Scientists who tend to speak cautiously, respecting all that is uncertain in such work, were positively gushing. “We’re turning the page on many, many new chapters in astrophysics,” René Doyon, a principal investigator with the Canadian Webb science team and a University of Montreal astronomy professor, told The Globe and Mail. “Everything is going to change completely.”
The first image came out on Monday at the White House. It was a Deep Field picture, as the Webb peered at a galaxy cluster as it existed 4.6-billion years ago. And because of the gravity of that cluster, the Webb was able to register light from one galaxy as far back as 13.1-billion years – touching the beginnings of a universe that is roughly 13.8-billion years old.
In technical terms, the Webb observes infrared light, unseen by the human eye, and collects it with a microscopically smooth gold-plated dish 6.5 metres in diameter.
The result, that first image, is scientific but, almost more so, magical.
The colours and shapes of galaxies from so far in the past invite people to stare. The picture is hypotonic. It is almost a visual definition of infinity. While it seems so vast, NASA said it is a patch of sky the size of a grain of sand held at arm’s length. It may feel infinite, yet it is only a tiny sliver of the universe.
On Tuesday came three other images, all spectacular. The Webb, in this first round of many, scoped out known celestial landmarks. One was the edge of a region called NGC 3324 in the Carina Nebula, a mere 7,600 lightyears away. This zone of stars being born was first catalogued in 1826. Hubble gave us an incredible image, and Webb provides much more.
Such progress is imbued in the Webb project. One example is the Webb’s location in space: Its crucial destination was mathematically mapped out on paper in 1772.
The Webb is at once culmination and a starting line.
Perhaps the most fascinating release this week was not a picture but a chart of data, wavelengths of light from the planet WASP-96b. The data showed “the distinct signature of water.” It was measured with the Webb’s near-infrared imager and slitless spectrograph, built by the Canadian Space Agency.
The Hubble in 2013 first saw faint signs of water on several distant planets, though none suited to life. WASP-96b is likewise, but the Webb, and Canadian scientists, will soon look at planets orbiting the star TRAPPIST-1, where the possibility of science-changing discoveries are greater. NASA this week said Webb’s WASP-96b data “marks a giant leap forward in the quest to characterize potentially habitable planets beyond Earth.”
Discovery is the heart of what the Webb is about. The greatest telescope ever built will help us understand much more about how galaxies and stars formed, give us a closer look at the beginning of time, and possibly offer us clues to the age-old question: Is there life out there?
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