Stellar nursery 30 Doradus gets its nickname 'Tarantula Nebula' from its long, dusty filaments. Located in the Large Magellanic Cloud galaxy, it’s the largest and brightest star-forming region near our own galaxy, plus home to the hottest, most massive stars known.
Almost a year after launch and five months into its mission, JWST has been working non-stop, peering into space and discovering the unexpected.
Astronomers are finally able to realize the promise of this extraordinary, long-awaited telescope, decades in the making.
“We really are full steam ahead for science,” said JWST operations project scientist Jane Rigby at a recent press briefing. “This telescope is a gift that has taken months to unwrap.”
Included in that gift are some significant surprises. Rigby noted how virtually across the board, the observatory is more powerful than prelaunch expectations, as the images are sharper, the pointing and guidance are more stable, and overall, the telescope has better sensitivity than predicted.
Already JWST has delivered on its promise of seeing galaxies from the earliest epochs of the universe, helping us to understand how galaxies assemble over billions of years. It’s peered into massive clouds of dust, showing how stars and planetary systems are born. It has provided details about the atmospheres of distant extrasolar planets while searching for the building blocks of life. And it has studied objects in our own solar system — even watching another spacecraft slam into an asteroid.
This timelapse of images from NASA’s James Webb Space Telescope covers the time spanning just before impact at 7:14 p.m. EDT, Sept. 26, through 5 hours post-impact. Plumes of material from a compact core appear as wisps streaming away from where the impact took place. An area of rapid, extreme brightening is also visible in the animation.
“It's remarkable how well JWST is performing less than a year after launch,” says Mark McCaughrean, the European Space Agency’s Senior Advisor for Science & Exploration and part of JWST’s Science Working Group. “It surely is the most complex scientific space telescope ever, with many new technologies and ways of operating, and with very sophisticated instruments to collect and analyze the light.”
McCaughrean has marveled at how the six-month-long deployment, alignment, cooling, and commissioning process went so smoothly, rapidly giving way to full scientific operations.
“With just a few minor hiccups, JWST is now delivering huge amounts of data that are giving us a whole new view of the Universe,” he told Supercluster, “from our solar system to exoplanets, star-forming regions, and galaxies strewn across time. It's a real testament to the teams in North America and Europe that built it and operate it, a superb demonstration of what we can achieve when we work together.”
That said, McCaughrean cautioned, it is still early days for the new space observatory, and out in deep space, hazards loom everywhere. A larger-than-expected meteoroid slammed into one of the telescope’s mirror segments, causing more damage than expected — although engineers say this one hit hasn’t diminished JWST’s observing ability overall. Then, an issue arose with the telescope’s Mid-Infrared Instrument (MIRI) where excess friction was detected in the operational wheels, requiring a shutdown of one of the observing modes.
McCaughrean said the sensitive infrared detectors have well-known "quirks" which lead to all sorts of artifacts that need to be characterized and removed, requiring a huge effort to turn the raw data from JWST into reliable scientific results. Additionally, obtaining precise calibrations of the observatory is a time-consuming process that will continue for months and years.
Heidi Hammel, an interdisciplinary scientist with the JWST project agrees.
Image credit: NASA, ESA, CSA, STScI. Hidden in the neck of this “hourglass” of light are the very beginnings of a new star — a protostar.
“There have been some bumps along the road,” she said via email. “We had to wait some time for the MIRI situation to sort itself out, but the engineering team came through on that, and we have some sweet mid-infrared data under analysis now. Similarly, some of the instrument calibrations are still a work in progress, but that is to be expected in the first months of a brand-new facility. It is all getting sorted out.”
“Yes,” McCaughrean said, “none of this is bad and none of it is unexpected by the astronomy community — we're used to debugging state-of-the-art observatories and solving complex data analysis problems.”
But with the jaw-dropping images and surprising findings JWST has already provided so early in its tenure, McCaughrean believes expectations might be a little too high going forward.
“The sheer beauty of the relatively few images released publicly so far has perhaps raised an expectation that a flood of paradigm-changing findings is imminent,” he said. “In reality, in many areas, it's going to take us a bit longer to make sure we have a completely solid understanding of how the telescope and its instruments work, and thus be able to deliver not only exciting but also reliable results.”
For example, McCaughrean’s own data from JWST observations — namely the Orion Nebula and two protostellar jets, HH211 and HH212 — are providing challenges.
“They're spectacular and everything I dreamed of when I got involved with JWST more than 24 years ago and became a member of the Science Working Group in 2002,” he said. “But they're also fairly raw and I suspect that it'll take us many months to calibrate them, analyze them, and tease out the discoveries they hold. It's what we all signed up for, however, and it still seems quite surreal that we're finally at this point.”
Amidst the difficult and time-consuming work, astronomers have also experienced some incredible highlights in the first few months of observations. Rigby and Hammel both cited the DART spacecraft’s intentional impact on an asteroid as tops on their list. JWST was able to track and image the Double Asteroid Redirection Test’s refrigerator-sized robotic probe as it crashed into a 560-foot-wide asteroid called Dimorphos on Sept. 26. The impact caused a larger-than-expected change in the asteroid’s orbit. This outcome bodes well for any future potential asteroid redirection that might be necessary for a space rock that threatens Earth, and JWST’s observations helped confirm the results.
Dimorphos, about 4 hours after NASA’s DART made impact. A compact core and plumes of material are visible in the image. Those sharp points are Webb’s distinctive eight diffraction spikes, an artifact of the telescope’s structure.
“I was logged into the telemetry and watched it come down,” Rigby recalled. “That was exciting because we had worked so hard to get those observations to work. In doing so, we were able to support another NASA mission, providing insights into how asteroids are put together and what we might need to do to protect ourselves. That made my day.”
The observations were incredibly difficult and required a huge amount of coordination.
“We needed JWST to track the moving asteroid target at a rate more than three times the ‘upper limit’ we thought the telescope could perform,” Hammel explained. The telescope performed spectacularly, and the engineering team has now increased the ‘speed limit’ for the fastest target they can track.
As members of JWST’s Science Working Group, astronomers like McCaughrean and Hammel have what is called Guaranteed Time Observations (GTO), early observation time provided to scientists who helped develop the telescope from the beginning. As a planetary scientist, Hammel’s coveted targets include objects in our own solar system, such as Mars and Jupiter.
“Mars is one of the brightest objects in the night sky,” she said, “however, JWST was designed with the sensitivity to detect the faintest objects.”
Also, because solar system objects are so close, they move incredibly fast, relative to the rest of the universe. All of that provides challenges in observing, and a juxtaposition of this powerful telescope’s abilities. But with the help of the teams at the Space Telescope Science Institute (STScI) — the institution that operates JWST — and some clever planning and analysis work by the Mars Principal Investigator Geronimo Villanueva, Hammel said she and her team of observers were able to get spectacular images and spectra.
“Overall, my team has been getting fantastic data,” she said. “It has been so exciting and gratifying to watch them dig into the images and spectroscopy! After more than 20 years of anticipation, JWST has exceeded my expectations, and I give credit to the fabulous engineers who built it, the crackerjack team at STScI operating it, and my top-notch GTO team members for crafting such a great observational program of Solar System observations.”
Graphic Credit: NASA. Webb’s unique observation post nearly a million miles away at the Sun-Earth Lagrange point 2 provides a view of Mars’ observable disk (the portion of the sunlit side that is facing the telescope). As a result, Webb can capture images and spectra with the spectral resolution needed to study short-term phenomena like dust storms, weather patterns, seasonal changes, and, in a single observation, processes that occur at different times (daytime, sunset, and nighttime) of a Martian day.
One of those engineers, Lee Feinberg, the Optical Telescope Element Manager for the mission — whose 20-year career in developing JWST we profiled in February — said it’s been gratifying to see the results of the telescope in action.
“I think the first highlight for me was our first engineering image of a star which had so many galaxies in the background — we didn’t expect that,” he said. Another highlight came in the first official images released from the telescope because they were so striking.
“I think we are all surprised at how well everything is working, especially the optical and pointing performance because that means even better science,” Feinberg said via email. “I’m super proud of our entire team, especially the many individuals who worked so hard for so long, many of whom you would never even know about.”
But now that the fledgling telescope is out on its own, so to speak, there are also some mixed emotions for Feinberg.
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“The one thing that is a bit bittersweet is that much of the development team has now moved onto other projects, but they have passed the baton to an incredibly capable operations team flawlessly,” he said.
For the engineering teams who now operate the telescope and the scientists who are making observations, the fun is just getting started.
“As one of the people who helped commission this telescope,” Rigby said, “it's lovely to see the joy and excitement of the teams, now that the early data are in the hands of scientists around the world, and we’re seeing the discoveries come out. The teams are analyzing the data, churning out science, and making discoveries, and now they are proposing follow-up discoveries to deepen our understanding. That’s exactly what we wanted to see.”
And when we discover the unexpected, we really learn something new about the universe.