Today, 365 days after NASA released the mission’s first batch of data and images, it’s clear that JWST can produce hard science and beauty scenes with equal passion. NASA marks the first anniversary of JWST’s science debut by releasing a new image, demonstrating the telescope’s ability to reimagine the universe. The dramatic, somewhat hallucinatory image captures the activity of the Rho Ophiuchi cloud complex, the closest star-forming region to Earth, where planetary systems like ours may be in the early stages of formation.
“The telescope is performing better than we expected,” said NASA astrophysicist Jane Rigby, who became JWST’s senior project scientist earlier this month.
Rigby said the scientific community was a little conservative in planning the agenda for the first year of observations, but this next year Science will take full advantage of what the telescope can do. “We’re getting bolder in year two.”
JWST’s journey around the Sun has not been without speed bumps. The first year of scientific operations included a brief pause in data collection for safety reasons and a heart-stopping collision with space dust that forced project managers to fly the observatory more or less backwards from now on.
But scientists working with the telescope’s downloaded data are thrilled by its performance, which looks into the infrared part of the spectrum, gathering light that its predecessor, the Hubble Space Telescope, couldn’t.
The big headline so far is that JWST has spotted some surprisingly bright galaxies in the early universe. It was a bit confusing.
No, JWST does not disprove the Big Bang theory. Cosmology does not go the way of phrenology. But observations of so much light from the early stages of galaxy formation have led to some head-scratching. Observation and theory are not well aligned.
“I think there’s a tension,” said JWST mission leader physicist Massimo Stiavelli of the Space Telescope Science Institute in Baltimore. “It’s undeniable because things are different than we thought.”
Key Findings of JWST
JWST was created in the late 1980s as a successor to the still-unlaunched Hubble, but faced years of delays and a near-death encounter with budget-strapped lawmakers. It is a $10 billion investment. It’s not designed with modular features that enable replacement parts if something screws up.
And it’s deep in space, in a gravitationally stable orbit around the Sun called L2, about a million miles from Earth. NASA currently has no space shuttles to carry astronauts to L2 and back.
All this reinforces happiness among scientists that the telescope is working as planned.
For a telescope of this design, a year is a big deal. The telescope’s mirrors must be very cold and can’t be pointed anywhere near the Sun, so don’t expect to see any pretty JWST images of Venus. But a full orbit gives the telescope the opportunity to cover much of the universe.
JWST, which launched on Christmas morning in 2021, actually made one and a half orbits, but the first six months were devoted to using its massive gold-plated array. Hexagonal mirrors and a wide sunshade to keep them cool, as well as fine tune its instruments.
The light collected by those mirrors carries information about many layers of the universe, from distant, faint, barely perceptible galaxies to the most active galaxies in the foreground and star-forming clouds of dust and gas within our own Milky Way. And it looks at our immediate neighborhood, the Solar System, sending back poster-worthy images of Jupiter and Saturn crammed with scientific data.
The early universe is where JWST has made some of its most interesting and sometimes perplexing investigations. The goal is to understand how the early universe formed, how galaxies formed and how we got to where we are—on a planet orbiting a star in one of the spiral arms of a large galaxy.
“Our home is the Milky Way,” said theoretical astrophysicist Brandt Robertson of the University of California, Santa Cruz. “It’s a galaxy. It is a beautiful constellation. We can take pictures from inside. But that begs the question: How did it get here? How did it come about?”
It is this cosmic archeology that JWST was built upon in the first place. A strange feature of the universe is that light is eternal. It fades, but it’s still there, including the oldest light, heavily shifted into the infrared part of the spectrum by the expansion of space that occurred after the Big Bang. Astrophysicists can scan far more using JWST High-redshift galaxies dig even deeper into the past.
Robertson co-authored one of two recent papers describing it The most distant galaxy ever detected and confirmed by JWST is named JADES-GS-Z13-0. It was discovered at redshift 13.2, which corresponds to about 320 million years after the Big Bang. There are claims of possible galaxies at higher redshifts, but they await confirmation, he said.
Asked what the galaxy looked like, he said, “It’s a blob.”
But what if you could somehow get on a spaceship, transport yourself through various wormholes into the distant past, and orbit next to that galaxy. Then what will it look like?
“If you can be right next to it, the galaxy will be very blue to your eyes because it’s making stars,” Robertson said. “It would be very blue bright in the early universe.”
A riddle about the earliest times
Now, astronomers looking at JWST data of the early universe have found something that defies expectations: a lot Different bright galaxies.
Luminosity is an approximation for mass. The brightest galaxies, therefore, are generally considered the most massive. But galaxies take time to grow. Theorists have previously developed a general timeline for the evolution of early galaxies, and those detected by JWST appear remarkably mature for their age at first glance.
JWST may be telling scientists that galaxy formation in the early universe was somehow more efficient than previously known.
“We have to make some adjustments to our theories of how those early galaxies formed and grew their stars,” he said. Jayhan Kurtaldeb, an astrophysicist at the Rochester Institute of Technology.
“Nothing we’ve seen makes us think we’ve cracked cosmology,” Rigby said. “What that tells us is that the galaxies merged earlier than we gave them credit for their actions.”
For those of us who aren’t astrophysicists, black holes may be another factor in the luminosity of those early galaxies. Although a black hole by definition is a system with a gravitational field so intense that even light cannot escape, the region around the black hole glows as gas and dust heat up and fall toward the event horizon.
Last year, Rebecca Larson, then a doctoral student at the University of Texas at Austin, noticed something strange. When he examined data from the most distant galaxy named CEERS 1019. Light – 13 billion years ago – back when the universe was rolling, and galaxies were tiny, awkwardly shaped cockles of hot, young, bright-blue stars.
Larson was puzzled by the unusually bright light coming from the center of CEERS 1019. “what a cruelty?” she thought.
She guessed it – correctly – as a supermassive black hole. The galaxy, though young, has already managed to grow a black hole that scientists estimate has a mass equal to 10 million suns. The report by Larsen and his colleagues describes it as the first active supermassive black hole ever detected.
Excited about exoplanets
Last year it began to show that JWST is a “spectroscopic powerhouse,” in the words of astrophysicist Garth Illingworth. It has proven to be amazing at picking out the spectra of light it collects, which contain information about the object being observed.
That ability yielded one of the telescope’s first major discoveries: carbon dioxide in the atmosphere of a giant planet, WASP 39b, orbiting a distant star. The planet itself is not visible with current technology. But as it passes in front of or behind its parent star, changes in starlight encode information about the planet’s atmosphere.
Until JWST, no one had reliably detected carbon dioxide in an exoplanet’s atmosphere, said NASA astrophysicist Nicole Colon.
“We saw the spectral signature of that feature for the first time, and it was beautiful,” he said. “It hit us in the face. And here’s this amazing signal, it was awesome.
To be clear, scientists looking at spectra are looking at graphical presentations of the data, not actual images. Larson, who discovered the supermassive black hole, was so moved by the spectral signature of a central bright region in the galaxy that, as he put it, “I never thought I’d see real images from JWST.”
It was then that Kurtaldeb showed her the image of the constellation through the telescope. Amazingly, the galaxy had three bright spots, with a particularly bright spot in the middle. That’s Larson’s biggest black hole.
“I started crying,” she said.