One year into science operations, Webb continues to rewrite the textbooks of science

by Haygen Warren

On July 12, 2022, five groups of scientists gathered in different agencies across the world to reveal the first five images taken by the historic NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope. The release of the images officially marked the beginning of scientific operations on Webb, which is positioned 1.5 million kilometers away from Earth at the Sun-Earth Lagrange point two, or L2.

In the year since the release of its first images, Webb has already begun to rewrite the textbooks of astronomy, planetary science, astrophysics, cosmology, and more. From revealing stellar nurseries previously hidden behind pillars of dust, discovering the most distant active supermassive black hole, finding vital carbon molecules in the protoplanetary disks of young star systems, and unveiling galaxies that existed when the universe was just a few hundred million years old — Webb has already proven itself to be a monumental piece of machinery and one that will forever have an impact on the world, its people, and the fields of science we study.

To learn more about Webb’s first year of science operations, the observatory’s current health, and what we can expect to see from the observatory throughout the next year, NSF sat down with Dr. Stefanie Milam, Webb’s Deputy Project Scientist for Planetary Science.

Webb’s First Year of Science Operations

As mentioned, Webb’s first year of science operations, commonly referred to as “Cycle 1,” began when the observatory’s first images were released on July 12, 2022. The images were of galaxy-cluster SMACS 0723, spectral data of exoplanet WASP-96b, the galaxies within Stephan’s Quintet, the Southern Ring Nebula, and the Carina Nebula. Each of the images well-represented the power of Webb and what its incredible suite of infrared-sensitive instruments could do.

The first four images from the James Webb Space Telescope: Southern Ring Nebula (top left), Carina Nebula (top right), Stephan’s Quintet (bottom left), and SMACS 0723 (bottom right). (Credit: NASA/ESA/CSA/STScI/Webb ERO Production Team)

Webb has a total of four instruments: the Near-Infrared Camera (NIRCam), the Mid-Infrared Instrument (MIRI), the Near-Infrared Spectrometer (NIRSpec), and the Fine Guidance Sensor/Near Infrared Imager and Slitless Spectrograph (FGS/NIRISS). These four instruments, along with Webb’s massive 6.5-meter mirror, have allowed scientists to view deeper into the universe than before and view some of the universe’s earliest galaxies and even black holes.

The full abilities of Webb would begin to be realized a little over a month later when NASA announced that the observatory had detected carbon dioxide within the atmosphere of an exoplanet. The gas giant exoplanet, named WASP-39b, is located approximately 700 light-years away around a star similar to our Sun. Webb used NIRSpec to provide the scientists with spectral data of the exoplanet’s atmosphere, where they discovered the carbon dioxide.

While being able to detect molecules within the atmospheres of planets outside of our own solar system is incredible, the discovery provided scientists and engineers with clear evidence that Webb would be capable of detecting other molecules in the atmospheres of not only gas giant exoplanets, but also small rocky exoplanets that are similar to Earth.

In early September, it was announced that Webb had already taken its first direct image of an exoplanet orbiting its host star. Using NIRCam, MIRI, and a coronagraph, Webb was able to image exoplanet HIP 65426 b, which is a gas giant exoplanet, in different bands of infrared light in both the near-infrared and mid-infrared regions of the electromagnetic spectrum. Similar to the detection of carbon dioxide in WASP-39b’s atmosphere, Webb’s images of HIP 65426 b highlighted the observatory’s incredible abilities when observing exoplanets.

Also in September, Webb — along with the Hubble Space Telescope — observed and imaged asteroid moonlet Dimorphos, which was directly impacted by NASA’s Double Asteroid Redirection Test (DART) spacecraft in an attempt to change the moonlet’s orbit around asteroid Didymos. Webb’s observations of the ejecta produced by DART’s impact allowed scientists to understand the surface of Dimorphos, how fast material was ejected from the surface, and the amount of material ejected by DART.

Webb’s image of Dimorphos and the ejecta from DART’s impact. (Credit: NASA/ESA/CSA/Cristina Thomas (Northern Arizona University)/Ian Wong (NASA-GSFC))

During this period of 2022, Webb began to image and collect data on the planets within our solar system. The observatory imaged both Jupiter and Neptune in August and September, respectively, and would go on to image the remaining two gas giants — Saturn and Uranus — in 2023. The images are allowing scientists to further characterize the atmospheres of the gas giants.

In late-2022, some of the first studies into the early universe using Webb were released, and scientists got their first look into just how far back Webb is able to look.

“There’s been a number of really big discoveries thus far. One is early galaxies. Webb is trying to be this cosmic time machine and detect the first galaxies and stars of the universe. And it turns out that the deeper we look, the more surprises we get,” Dr. Milam explained.

Due to the universe’s expansion and light only being able to travel at a certain speed, light becomes red-shifted from the visible to the infrared region of the electromagnetic spectrum. Because of this, visible telescopes like Hubble are unable to see the light from the very early universe, as much of the light from that period is extremely red-shifted into the near and mid-infrared regions.

Webb’s extreme sensitivity to infrared light, coupled with its large mirror, allows the telescope to see extremely far back into the very early period of the universe. In the time since those first early universe studies were released, Webb has discovered galaxies that existed when the universe was around 400 to 600 million years old — an incredible feat for a telescope less than one-year into its scientific operations. What’s more, Webb was even able to find active supermassive black holes in the centers of these galaxies, with one black hole, located in a galaxy called CEERS 1019 that existed when the universe was 570 million years old, being the most distant active supermassive black hole ever discovered.

The full Cosmic Evolution Early Release Science (CEERS) survey, in which the most distant active supermassive black hole was discovered. (Credit: NASA/ESA/CSA/Steve Finkelstein (UT Austin)/Micaela Bagley (UT Austin)/Rebecca Larson (UT Austin))

Webb’s data on galaxies from the early universe is revealing that many of the earliest galaxies in the universe were a lot more organized and structured than originally thought. Additionally, scientists had no idea black holes could’ve existed this early in the universe, yet Webb’s data is telling them otherwise.

“Early galaxies are actually a lot more structured and larger than what we had anticipated. And I think that’s a huge finding for cosmology in general because it’s telling us about how quickly everything got organized. It was a completely unexpected result. This is something I think is definitely going to impact that field in big ways,” said Dr. Milam.

As the years changed and into 2023, Webb continued to make advancements in exoplanet, solar system, and early universe observations. While the aforementioned studies and discoveries are massively important, they don’t even begin to scratch the surface of all the incredible things Webb has accomplished in its first year of scientific operations.

For Dr. Milam, who has her Ph.D. in chemistry from the University of Arizona in Tucson, Webb’s discoveries with exoplanets and asteroids are incredibly interesting and fascinating.

“I think the exoplanet science is everybody’s favorite. The more we look, the more we find or we don’t find. And that’s been a fun sort of thing that’s coming from JWST. We’re looking at these planets and trying to find the next Earth 2.0. And sometimes they don’t even have an atmosphere!”

“Seeing all the water vapor in these planets that are orbiting their star is just crazy. They’re so close to their star and yet there’s molecular material in their atmospheres. That’s insane. You would expect it to get completely annihilated or blown off, so what is causing that atmosphere? This isn’t even my field and I’m already just astonished and blown away,” Dr. Milam said.

“However, my favorite discovery was the detection of water in the main belt asteroid. We’ve been trying to detect anything in these active asteroids or main belt comets for a while. And even with Hubble, Keck, you name it, we haven’t been able to detect anything molecular on these objects. It took JWST to actually find that there was water vapor driving that activity. So now I think that’s just opening up a whole new area of science and research.”

Even though Webb’s first year of operations has proved to be massively successful, it wasn’t without its challenges.

While small issues have popped up from time to time, Webb’s MIRI has given engineers and scientists quite a few issues throughout the year. In late-August, teams noticed increased friction in one of the grating wheels used in MIRI’s medium-resolution spectrometry (MRS) mode. Due to the issue, no observations were carried out using the MRS mode until the issue with the wheel was fixed in November.

“We’ve had some glitches with MIRI. For example, one of the filter wheels was getting stuck. It took us a little bit of time to figure out why that was happening and our strategy to move forward so that we didn’t permanently get stuck in one configuration and also to understand just how that mechanism needs to be sort of babied or monitored as we move forward. We’re working through it, we’re still monitoring it, but we are operating and still using MIRI in its full capacity,” Dr. Milam said.

The issue with MRS was not the only issue MIRI would see in its first year, though. In April 2023, while performing a regularly scheduled maintenance check and calibration of MIRI, teams noticed a decrease in the instrument’s throughput, or the amount of light that is ultimately registered by MIRI’s sensors, at longer wavelengths when in the MRS mode. Interestingly, however, the throughput issue has had no effect on observations or the instrument and poses no risk to the health of MIRI.

“We’ve also this spring noticed that there was some throughput decrease since we launched. That, again, is something that we’re monitoring regularly, trying to understand if it was some initial degradation or if it’s something that’s continuously occurring. We have a whole team working on just basically making sure things don’t get any worse.”

“The good news is we understand what is happening and we’ve gone back and we’ve looked through the data. So, we’ve put in some calibration corrections for data that’s been acquired since launch. It kind of has a little timeline so that we understand what data was acquired and what calibration needs to be applied to that specific dataset and it’s been corrected for future observations,” said Dr. Milam.

“So everything as far as our tools, scheduling, and planning has been accommodated to take up whatever happened with this throughput. Everything is still performing, we are still using the instrument. It is still producing amazing data. It’s just how the numbers get basically converted from a count rate to an actual flux and what that means. It’s just a calibration correction right now.”

MIRI being integrated onto Webb in 2013. (Credit: Goddard Space Flight Center/Chris Gunn)

As mentioned, teams found the issue with the throughput via a maintenance check of MIRI. Teams perform regular checks on all instruments, not just MIRI, to ensure everything is in working order and that nothing is negatively affecting observations.

“All of our instruments undergo routine maintenance on just characterizing the detectors, making sure that the instruments are performing the way that they’re supposed to or that we expect them to. And that’s how we actually caught this in the first place. It was just one of our checks to see how things are going and then we saw something peculiar,” explained Dr. Milam.

Webb Now and its Next Year of Operations

As Webb prepares to head into its second year of operations, the observatory has now spent well over a year and a half in space. Given the harsh conditions of space, micrometeoroids, and the complexity of the observatory, how is Webb holding up at L2?

“The observatory is fantastic. Every image and data that we get back from it has been mind-blowing and rewriting textbooks,” Dr. Milam said.

Composite image of NGC 5086 using MIRI and NIRCam images. (Credit: ESA/Webb/NASA/CSA/J. Lee/ PHANGS-JWST Team)

“We are still getting through some aches and pains of just learning how to operate the observatory. Much of the first year of operations is just understanding all the complexities and what our challenges are as we move forward. So we’ve been trying just to really hone in on our operating efficiency and strategies for working through instrument issues or something like that. Even just doing our routine maintenance, we’re still learning how frequently we have to focus the telescope or do orbit corrections.”

Furthermore, the team has implemented various types of software and features into the observatory to help keep Webb in good health at L2. One such upgrade is the implementation of a micrometeoroid avoidance zone.

“We have implemented a micrometeoroid avoidance zone to basically avoid blasting head first into a hailstorm. Hopefully, that helps us with major impacts, like the first one that we had last summer. We’ve had a handful of them since then and we’ve been able to monitor what the size of those are and what kind of damage we think that they’re impinging upon the observatory,” explained Dr. Milam.

“Hopefully that’ll help us in the long run with just maintaining the health and safety of the observatory and trying to keep our optical performance as superior as it already is.”

Webb heading into its second year of operations means that a new collection of scientific projects and teams will be given time with the observatory over the course of next year, which is being called Cycle 2.

Given the incredible discoveries Webb made in its first year and the sheer power of the observatory’s instruments, thousands of teams and projects from around the world are trying to get time with Webb. However, time is not just awarded on a first-come-first-serve basis. Instead, a thorough selection process is followed by both Webb teams and the projects/teams that apply for time with the observatory. The entire process begins with an annual call for proposals.

“You have to submit a scientific proposal and justify why you want to use Webb and what instrument, mode, etc. All of those proposals then go under peer review. There is a special group of people called the Time Allocation Committee, which are the scientific community. Committee members are actually picked from the community. It’s nobody internal to the project or to the space telescope. They read all of the proposals and break them up into different categories so that a scientist is not reviewing something that’s outside of their scientific expertise,” Dr. Milam said.

“The committee meets and they review the proposals, and they give them grades. And every proposal is reviewed by a number of people, giving the proposal an average grade. A certain grade level is what we call being ‘triaged,’ which means those proposals are absolutely not going to get time. The proposals that are in a high enough grade level, go to the panel. The committee then sits down in a room together, and they discuss those proposals with the higher rankings. They discuss whether or not those scores justify what they read in the proposal. Maybe there are some people with more specific expertise on a given topic and they can weigh in on the merits, the strengths, or the weaknesses of a given proposal.”

After the higher-graded proposals go to the panel and are discussed by the committee, teams will go through and determine how much time there is to award. When determining the amount of time to give to scientific operations, teams have to take into account the time needed to perform regular health checks, orbital corrections, and more. To make awarding time easier, each category of science that is proposed will get a certain amount of time per year.

“Each category gets a certain amount of time based on how many proposals and how much time was requested for that category. So, solar system science will get some portion of time based on how many solar system proposals there were. Extragalactic proposals will get some proportion based on the number of proposals and so on. And so whenever we get the final ranking of the proposals in a given category, we know how many hours we’re going to award to certain proposals. The recommendation of the proposals that the panel decides goes to the director who signs off and gives the final decisions,” explained Dr. Milam.

“It’s a blind process. We don’t know who the proposers are. The proposers don’t know who the reviewers are. And so that makes it a nice fair opportunity for early-career scientists or people from less-prominent countries to actually have the opportunity to be awarded time based on the merit of the proposal and not necessarily of the scientist. It’s a nice, blind way to do it, and it’s been proven to be a very successful way to bring in new scientists.”

However, as Webb continues to make new discoveries that intrigue the scientific community, does the amount of time awarded to certain proposals in categories like exoplanets, galaxies, black holes, etc. change based on the importance or quality of data received the year prior in those categories?

“Absolutely, because there’s always going to be new things that we find regarding the capabilities of the telescope,” Dr. Milam said.

Webb’s image of the three disks of Fomalhaut — one of which being an asteroid belt. (Credit:NASA/ESA/CSA/A. Gáspár (University of Arizona)/A. Pagan (STScI))

“For example, we know how long it takes to really study an atmosphere of a planet in the TRAPPIST system. And so we take that knowledge, that innate knowledge of how things worked in previous years and that builds into how we justify writing a science proposal or how we would review one the following year. Or if they want to do the DART mission impact, well, we know that we can now do that. That’s something we now have the capability to do. That’s something we now know, for future cycles, we can offer.”

As mentioned, the proposals for Cycle 2 have already been selected and announced. While many of the same types of objects will be observed with Webb, there are a handful of new objects that will be observed with Webb during Cycle 2. Furthermore, Webb will be re-observing various objects that were observed in Cycle 1 to build upon the data that has already been collected.

“We’re gonna go back to Enceladus! We’re gonna look really, really hard at the plumes and try to see if we can detect anything else. We’re also going to try to understand what that plume activity actually looks like. Is there any variability that we can possibly detect? So they’re gonna do a much deeper dive into Enceladus and that’s really, really exciting,” Dr. Milam said.

“We’re also going back to main-belt comets, looking at more of those, seeing if we can detect more water, maybe even detect carbon dioxide this time. Obviously, this is a first and exciting different realm for Webb. We’re also in the queue for looking for an interstellar object. If we get another one in the solar system, all hands are on deck and we’re ready to go with JWST.”

Webb’s first anniversary image, which shows Rho Ophiuchi — the closest-star-forming region to Earth. (Credit: NASA/ESA/CSA/STScI/Klaus Pontoppidan (STScI))

“Then there’s all the galaxies, all the exoplanets. We have a huge exoplanet program for Cycle 2. Lots of time was awarded to study planets around other stars. And that’s a really hot area of science right now. So I think there’s gonna be a lot of good discoveries coming in the next year of science.”

Lastly, in the next few weeks, all of Webb’s incredible data from Cycle 1 will be released to the public. This means anyone can access and work with the data Webb collected, which could possibly yield even more discoveries.

“The best part is, after one year, all of that data becomes absolutely available to the public. So anyone in the world — junior high kids or your grandma — could go and look at the data. That’s there for anyone in the world to use and take advantage of. So that’s very exciting.”

(Lead image: Artist’s illustration showing Webb at L2. Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez)

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