Arianespace's Ariane 5 rocket, with NASA's James Webb Space Telescope aboard, lifts off Dec. 25, at Europe's Spaceport, the Guiana Space Center, in Kourou, French Guiana.JM GUILLON/The Associated Press
On Earth, in these darkest days of the year, life feels especially bleak. Omicron surges, climate heating worsens.
But up in the sky, something remarkable: The greatest telescope ever built is on a month-long journey to a home 1.5 million kilometres away where, once fully operational, it will peer out to the beginnings of the universe, and also seek to reveal the elements of life on Earth-like planets closer – relatively speaking – to home.
The James Webb Space Telescope project, led by NASA with contributions from Europe and Canada, launched Dec. 25. It’s headed to a Lagrange point, around which it will orbit, with the Earth and moon between it and the sun. The destination was mathematically mapped out in 1772, Essai sur le problème des trois corps.
Gravity of Earth and sun will help keep the telescope in position. It will be close enough to easily keep touch with Earth, draw on solar power, and, with a five-layer sunshield of human-hair-thin plastic, keep itself chilled out. The gold-plated telescope, 6.5 metres in diameter, will be a collector of infrared light, invisible to the eye but felt as heat. This requires something colder than the worst of Canadian winter: -223 C.
The goal is to absorb light emitted from the first stars and galaxies as they formed 13.6 billion or so years ago, and as far back as 100 million years after the Big Bang. The wavelengths of once-visible light stretched out into electromagnetic radiation over their long journey from the universe’s ancient past to our present.
The Webb telescope picks up where the Hubble Space Telescope left off. Launched in 1990, with its focus adjusted by astronauts in 1993, the Hubble is an optical telescope in orbit 600 kilometres above the Earth. The Hubble unveiled glorious images and, in 1995, propelled humanity’s understanding of the universe’s formation. For 100 hours, the Hubble turned to look at nothing – a sliver of darkness. The result – the Hubble Deep Field – revealed a “bewildering variety” of primordial galaxies. It was a picture of the past never before imagined.
Looking even further back is the first of the Webb telescope’s four primary missions. It will also gaze closer to home at planets such as Neptune. But the other mission that has a shot to make us rethink life as we know it is to stare at rocky planets that seem similar to ours. The Webb will try to discern variations of light that could show “biosignature gases” in an atmosphere – a testament to life.
In 2010-11, the Kepler space telescope saw the first rocky planet outside this solar system, a mere 560 light-years away. Several thousand have been found since. A few of the most promising orbit the star TRAPPIST-1, a hop, skip and a jump away, a bit less than 40 light-years. Part of Aquarius, for the astrologically minded.
It is there, and throughout the Webb project, that Canada contributes. Canadian scientists will lead or co-lead a 10th of the telescope’s first cycle of projects. Among them is a University of Montreal physicist who will examine TRAPPIST-1 planets. Canada also produced two important components of the telescope: first, the fine guidance sensor, to keep the telescope fixed on target; and second, the near-infrared imager and slitless spectrograph, which helps explore nearby solar systems.
The launch last Saturday was successful. There are in-flight challenges, repeatedly tested on Earth. The level of precision is hard to fathom. The telescope is so smooth that it has been likened to an entire continent that features only fist-sized dimples.
Humanity has always been beset by one calamity or another, and humans have forever looked up at the stars for answers. Four hundred years ago came the first telescopes; 52 years ago, humans landed and walked on the moon. The Webb telescope will search for the origins of the universe and the elemental stew of life. Its many hoped-for discoveries promise to sharpen, and possibly revolutionize, astronomy, physics and philosophy. The question of whether we are alone could melt away for good.
The muck of the present will always be here. Gaze upward, like always, with awe. But while the Webb looks to the beginning, while it looks for signs of life way out there, take a moment to also look at this remarkable planet, where so much life flourishes. There is wonder down here, too.
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