Nico Cappelluti’s first look at the telescope that will offer the clearest glimpse yet of the Universe’s cosmic dawn came nine years ago, when the young astrophysicist visited NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Back then, only the powerful telescope’s 18 beryllium mirror segments were on site, awaiting the arrival of the flight structure, or essentially the ‘‘bones’’ onto which they would be mounted.
But even a partially assembled James Webb Space Telescope was enough to astound Cappelluti. “It was enormous,” he recalled of the instrument’s 21-foot 4-inch-long primary mirror, which is made up of the 18 hexagonal mirror sections. “I looked through an observation window into the cleanroom, where this massive telescope sat. You just had to be there to appreciate its size.”
At the time, Cappelluti was a postdoctoral fellow at the Italian National Institute for Astrophysics. While he was aware the Webb telescope wouldn’t launch until nearly a decade later, he still wanted to take an early gander at the instrument that promised to be a gamechanger for astronomy and, more specifically, for his research on super massive black holes.
Now, after more than 30 years in the design, production, and testing phase, the Webb is finally rocketing into history. Perched atop an Ariane 5 rocket, it blasted off this past Christmas morning from a spaceport in Kourou, French Guiana, carrying the hopes of Cappelluti and thousands of other scientists who have longed to unlock the secrets of the universe.
“I woke up early that morning just to watch the launch, making sure to be very quiet so that I wouldn’t awaken my young son,” said Cappelluti, who is now an assistant professor of astrophysics in the University of Miami College of Arts and Sciences. “I wanted to see the liftoff, then watch my son open his presents,” he said.
For Cappelluti, Webb’s Christmas Day launch was the biggest present he could ever hope for.
The most powerful observatory ever sent into space, the JWST, as it is sometimes called, comes with a $10 billion price tag and is an international collaboration involving NASA and the European and Canadian space agencies.
The telescope’s eventual orbit around the sun will place it some one million miles from Earth. And once fully deployed, it will observe light from the first galaxies that formed after the Big Bang and allow astronomers to study the atmospheres of exoplanets that orbit distant stars and to search for signs of alien life.
The JWST is the long-awaited successor to the famous Hubble Space Telescope. But it is 100 times more powerful, possessing infrared vision, which allows it to see through cosmic clouds of dust—Hubble sees primarily visible light.
And that’s why Cappelluti is so excited about Webb.
“Infrared light is the signature of distant objects, and that’s what the James Webb will allow us to see,” he explained. “It’s been designed to study an epoch of the universe we need to learn more about—the first billion years after the Big Bang. That’s when the universe produced the most amazing things we see today, produced the first stars, the first galaxies, and the first super massive black holes, which is the focus of my research.”
Found in the centers of huge galaxies, supermassive black holes are millions, if not billions, of times as massive as the Sun. How they formed is one of the critical questions the Webb telescope will help Cappelluti to answer.
“We have no idea why super massive black holes are so big, because they didn’t have time to grow to such enormous sizes. I’m talking about billions of solar masses,” he emphasized. He and his colleagues have advanced at least one theory as the reason, suggesting that some sort of physical mechanism early in the universe’s existence produced these strange regions in space where gravity is so strong that it bends light.
“We’re trying to see if these super massive black holes formed during the Big Bang and if they account for the missing mass in the universe, which is dark matter,” Cappelluti said. “We know that most of the matter we see in the universe is not visible, so we’d like to know if super massive black holes are indeed dark matter and if that dark matter is at the origin of these super massive black holes. The James Webb will contribute to answering those questions.”
NASA’s flagship telescope has already performed a handful of critical maneuvers during its journey to the second Lagrange point in space, unfurling its massive umbrella-like shield that will protect its delicate instruments, deploying a radiator-type instrument, and extending its secondary mirror. Other deployments will occur before the telescope’s final configuration is complete.
Its mission lifetime could last for as long as 10 years.
The first publicly available images aren’t expected until June. So, until that time, it’s a waiting game—along with hopes that nothing catastrophic happens. Unlike Hubble, which is in low-Earth orbit, the Webb telescope is too far away and beyond the reach of any crewed repair mission.
Thousands of hours of observation time have been allocated for the Webb telescope’s first year of operation. Those who helped build and design the instrument will get a significant portion of that time, releasing early-science data to the public, according to Cappelluti.
“After that, in order to use the James Webb, we’ll have to compete with other astronomers for observing time,” he explained. “We’ll have to submit proposals, which will be peer-reviewed and ranked, with only the best ones being assigned observing time. And observing time is the most valuable source of data you can have.”
Named for the NASA administrator who led the agency’s Apollo moon-landing program, the Webb won’t be the only source Cappelluti will rely on to answer questions about black holes.
“Astrophysical objects emit light at every wavelength, from X-ray to radio. The James Webb will allow us to see infrared light; but at the same time, we will also use other instruments,” Cappelluti said. He noted the Chandra X-ray Observatory—which launched aboard the Space Shuttle Columbia in 1999 and detects X-ray emissions from extremely hot regions of the Universe—and LISA, the Laser Interferometer Space Antenna, which is planned for a 2037 launch and will be the first space-based gravitational wave observatory.
Cappelluti started studying the planets from the backyard of his home in Rimini, Italy, when he was 6, peering through a telescope his father bought him. “It was a 60-millimeter telescope, and it was so exciting for me,” he recalled.
He is not the only University of Miami scientist fascinated by and anxious to see what the Webb telescope reveals.
“I’ve read many articles about all the amazing things it will see. The most exciting part, though, will be all the extraordinary things we don’t know exist but will be revealed by JWST,” said Massimiliano Galeazzi, professor and chair of physics, whose research involves the construction of X-ray detectors for space.
“Seeing beyond the tip of the iceberg—that’s what the Webb telescope will enable us to do,” said Alessandro Peca, a Ph.D. student studying physics and astronomy. “The James Webb will help us here on Earth in ways we can’t imagine yet.”
