Billions of years ago, long before the swirling cloud of gas and dust combined to form the sun, light left the earliest stars and began its long journey through space.
Since then, light has traveled, covering trillions and trillions of miles. It was carried by the galaxies and their nascent stars, some of which were accompanied by planets. And on one of them, a species has evolved that can not only ask questions about what might be there, but also create tools to see what its own eyes could not see.
On Monday, the world saw this ancient light for the first time thanks to NASA. James Webb Space Telescopethe most sophisticated and ambitious deep space viewing instrument ever created.
This is a deep space shot, the light from countless galaxies swirling around a central point like the light from a disco ball. Accompanied by President Biden and Vice President Kamala Harris, NASA Administrator Bill Nelson unveiled the image at a White House press conference.
“If you hold a grain of sand on your fingertip at arm’s length, that’s the part of the universe that you see – just one small dot of the universe,” Nelson said.
Webb is the successor Hubble Space Telescope, which changed the idea of science about the immensity of the universe. One of the most famous images of Hubble, Extremely deep fieldshows patches of light representing about 5,500 galaxies, the faintest of which allow us to look back in time 13.2 billion years.
Webb allows astronomers to magnify Hubble’s dimmest points.
“It’s an emotional moment when you see nature suddenly revealing some of its secrets,” he said. Thomas Zurbuchen, Associate Administrator, NASA Science Mission Directorate. “This is not an image. This is a new worldview. You will see how nature will reveal the secrets that have been there for many, many decades, centuries, millennia.”
Webb can literally see galaxies far, far away as they were a long time ago—just a few hundred million years after the Big Bang. It intercepts light in the infrared part of the spectrum, the wavelength of which is too long to be visible to the human eye.
Built at the Northrop Grumman Space Park in Redondo Beach, Webb was launched on Christmas Day from French Guiana. His destination was L2, the scientific shorthand for the second Lagrange point, about 930,000 miles from Earth. It is one of five places where the gravitational forces of the Sun and Earth are in balance, allowing Webb to stay at a fixed distance from our planet.
It took the telescope almost a month to get there. Then the telescope slowly and leisurely turned around in two weeks.
A complex system of latches, cables and pins freed the five-layer Sunshield the size of a tennis court. Once that was in place, the telescope’s 18 hexagonal mirrors snapped into place, creating a honeycomb structure 21 feet in diameter. The process wouldn’t seem out of place in an episode of Transformers. (Indeed, NASA released short video about Webb featuring Peter Cullen, the actor who voiced Optimus Prime in the original 1980s cartoon.)
Each mirror is plated with 100 nanometers of gold to enhance its ability to reflect infrared light. They were carefully aligned, focusing on the cumbersomely named 2MASS J17554042+6551277. test imagereleased to the public in March showed a bright star that appeared to emit light from six points, a characteristic of the telescope’s hexagonal mirrors.
But the background caught scientists’ attention: Behind the star, there were countless patches of light, each representing a galaxy billions of years old.
It was a tantalizing look at the scope of the telescope.
Hubble, launched in 1990, has offered unprecedented insight into the cosmos over decades of service. His observations helped scientists determine age of the universe and its expansion ratealong with the discovery of black holes, obscure moons and exoplanets.
But Webb is exponentially more powerful. Its mirror is six times larger than Hubble’s, which means it can collect much more light and see into the past. It also has a much greater ability to study infrared light.
Webb wouldn’t work if it was where Hubble is. The new telescope is so much more sensitive that light and heat from the Earth, Moon and Sun will overwhelm it. But its distance also means it’s too far away for spacewalking astronauts to repair it by hand, as Hubble has done five times since its launch.
Hubble had been in the skies for less than a decade when NASA started talking about the technology that would eventually replace it. Construction of the new telescope, named after NASA’s second administrator, began in 2004 with a $1 billion budget and a target launch date of 2010.
But the budget and timeline grew almost as fast as the universe he was supposed to explore.
The team needed more than just making sure the telescope’s materials and technology would work properly once launched into space. In many cases, given the innovative nature of the device, they also had to invent these materials from scratch.
Segmented cryogenic mirrors, a five-layer sunshield, infrared-capturing microshutters all had to be designed and tested in the lab before being made for use in a telescope.
Soaring costs ate into the budgets of other NASA projects. In 2011, Congress introduced a bill to completely eliminate the project. If such a great risk fails, “the progress of astronomy may be set back for a whole generation.” Nature magazine warned in 2010.