Telescope’s payoff to be, well, cosmic

Besides being significantly larger than its predecessor, the Hubble, this new telescope can see infrared light, allowing it to peer through the veil of dust that obscures some regions of space.



January 4, 2022 - 9:16 AM

The project has been in the works for years. In 2017, Joel Green, an astrophysicist, talks about how the James Webb Space Telescope works as he stands next to a model of it at the Space Telescope Science Institute in Boston. (Lloyd Fox/Baltimore Sun/TNS)

Like many other packages delivered on Dec. 25, a new telescope arrived in space Saturday with some assembly required.

The gradual unfolding of the James Webb Space Telescope, currently en route to its station 930,000 miles from Earth, is high drama. The long years of development, complete with the invention of several new technologies and the investment of billions of dollars, now depend for their success on many things going right.

With hundreds of things that could go wrong on its 29-day journey, Webb — which is named after the man who led NASA from 1961 to 1968 — represents a gamble of appropriately astronomical proportions.

But the potential payoff is cosmically huge as well.

“This telescope will be able to see back in time significantly farther than other telescopes can,” said James Flaten, associate director of NASA’s Minnesota Space Grant Consortium. “Being so much bigger than anything else that’s available, it will be able to see things that are significantly fainter, and hence things that are significantly farther away. Which basically means significantly older.”

In conversation with an editorial writer, Flaten pointed out that Webb’s light-gathering mirror, at 6.5 meters across, is significantly larger than that of the Hubble Space Telescope, which measures just 2.4 meters. But Webb has another advantage: its ability to see infrared light. That will allow it to peer through the veil of dust that obscures some regions of space.

Arianespace’s Ariane 5 rocket launches with NASA’s James Webb Space Telescope onboard, Saturday, Dec. 25, 2021, at the Guiana Space Centre in Kourou, French Guiana. The James Webb Space Telescope (sometimes called JWST or Webb) is a large infrared telescope with a 21.3 foot (6.5 meter) primary mirror. The observatory will study every phase of cosmic history from within our solar system to the most distant observable galaxies in the early universe. (Chris Gunn/NASA/TNS)

“A whole bunch of stuff that we currently can’t see well at all will become visible,” he said. “And considering how large it is, it can see significantly fainter things, and hence it can see things that are older. The reason being that the older something is, the farther away it is and the fainter it is.”

A NASA tracking tool shows the projected timetable for various benchmarks in the telescope’s mission. By now, Webb has cleared the moon’s orbit and will soon deploy its multilayered sunscreen and unfold the gold-coated mirror. A specially designed cooling system will keep the observatory cold enough to pick up infrared light from distant targets.

It’s all delicate, and critical, and inaccessible to any conceivable repair if something should go wrong. Webb’s eventual position, balanced between the gravitational influences of Earth and the sun, is four times farther away than the moon. NASA could, and did, send crews to repair Hubble, but Webb will be on its own.

Assuming all goes well, Webb will show us wonders; but as Flaten noted, “it’s a little hard to say what they will be.” No one has seen the universe as it looked quite so fresh from the Big Bang. And Webb should be able to give us a much better look at planets outside our solar system — even allowing scientists to determine the contents of any atmospheres they find.

Flaten cautioned that Webb is not designed to search for life elsewhere in the universe, although it should be able to find indications of liquid water or other conditions that might make life more likely. Of course, other kinds of life may turn out to thrive in environments that we would consider hostile. It’s all a question of your perspective.

And if Webb does what it’s designed to do, our perspective may be about to change.