A Korean Was Behind the Brilliant Achievements of the Web Telescope [Reading Science]

Interview - Son Sangmo, Senior Researcher at the US Space Telescope Science Institute
JWST Optical Focus Lead, Overseeing Commissioning Process for the Past 6 Months
"The Recently Released 5 Images Are a Preview, 13 Full-Scale Scientific Observations Underway"
"Korea Rising as a Space Power, Desirable to Participate in Large Projects Like JWST in the Future"

Sangmo Son, Senior Researcher at the Space Telescope Science Institute (STScI).

[Asia Economy Reporter Kim Bong-su] "Humanity will observe primordial stars never seen before with the James Webb Space Telescope (JWST) and find evidence of extraterrestrial life. An era where JWST's observational results lead astronomical theories is opening."

This is the statement of Dr. Sangmo Son (47), a Korean astronomer at the Space Telescope Science Institute (STScI), which operates JWST. Dr. Son serves as a senior researcher at STScI, established by NASA to operate JWST. He currently works on the JWST optical team and the Near Infrared Imager and Slitless Spectrograph (NIRISS) team, while also conducting research measuring the motions of nearby galaxies through various space telescopes to elucidate their formation and evolution. In a written interview with Asia Economy, he introduced that the recently released five JWST images are just a 'preview,' and thirteen major observation programs aimed at unraveling the secrets of the universe are underway. He also advised that Korea is rising as a space power and that participating in large-scale observation programs like JWST would help its leap forward. The following is a Q&A with Dr. Son.

-What kind of institution is STScI?

△Founded in 1981, the institute is located in Baltimore, Maryland, USA. NASA, which was conducting the Hubble Space Telescope project in the 1980s, established STScI after the telescope's launch, recognizing the need for an agency responsible for scientific operations. Similarly, STScI is responsible for all operations after JWST's launch. While it manages and operates the space telescope hardware, another major role is serving as a 'link' between astronomers who directly use the telescope. Scientists wishing to use the telescope submit proposals annually, which are reviewed fairly by experts who allocate observation time. Selected scientists are then supported with observation scheduling and various assistance to ensure successful research. After observations, STScI supports the appropriate use of data received from the space telescope for research.

Dr. Son worked on the Hubble Space Telescope team at STScI before joining the JWST team in 2019. He currently works as an optical focal plane expert on the optical team. During JWST's preparation, he was responsible for several tasks including mirror alignment, precise pointing (determining where the telescope is aimed), and focal plane calibration.

The Vela Nebula photographed by JWST.

-Please evaluate the five images released by JWST.

△The five images released on the 11th and 12th provide a glimpse of the kind of observational results JWST can achieve in the future. There are two main differences compared to Hubble Space Telescope images. One is that even small scales are seen in great detail, and the other is that galaxies fill the frame so densely that there are virtually no empty areas. JWST primarily observes in the long-wavelength infrared range and has a much larger mirror than Hubble. Despite shorter exposure times, it can capture such detailed and deep images. This raises expectations for the upcoming observations.

-JWST discovered water in the atmosphere of an exoplanet.

△The presence of a planet orbiting a star can be detected by observing the slight dimming of starlight as the planet passes in front of the star. The exoplanet WASP-96b observed by JWST was previously confirmed using this method. The recent detection of water vapor was achieved by spectroscopic observation of starlight during the planet's transit. Just as sunlight passing through a prism splits into colors, spectroscopic observation divides incoming light into various wavelengths. Starlight passing through the planet's atmosphere imprints the spectrum with various components present in the atmosphere, among which water vapor was confirmed.

WASP-96b is a gas giant with about half the mass of Jupiter and is located very close to its star, making the likelihood of life extremely low. The detected water vapor serves as a test case demonstrating how JWST can detect atmospheric components of exoplanets. JWST plans to observe the atmospheres of rocky, Earth-like planets using the same method. If components such as water vapor, methane, and carbon dioxide are detected in those planets, serious discussions about the possibility of life can begin.

Image analyzing the atmospheric composition of the exoplanet WASP-96b captured by JWST.

-What are the future observation plans?

△The targets range widely from nearby objects like Mars, Jupiter, and comets within the solar system to the very first stars formed after the birth of the universe. The recently released images were part of the Early Release Observations (ERO) program aimed at showing the public 'this is the performance level of JWST.' Separately, thirteen Early Release Science (ERS) programs are underway as pilot studies for astronomers to glimpse the specific scientific results JWST can produce. These include △studies of Jupiter's atmosphere, the largest planet in the solar system △direct imaging of exoplanets using a coronagraph (a device that blocks bright starlight to reveal faint planets) △observations of globular clusters and dwarf galaxies within the local group △and observations of galaxies of various masses to elucidate galaxy evolution.

Each year, observation proposals from astronomers worldwide are received and selected for observations. Besides JWST's fundamental goals of observing the first stars after the universe's birth and detecting signs of life in exoplanet atmospheres, many unexpected discoveries and results are anticipated.

On the evening of the 11th (local time), U.S. President Joe Biden held a pre-release event at the White House and unveiled the SMACS0723 galaxy cluster photo taken by JWST. Photo by YouTube capture.

-What changes will this bring to the scientific community?

△Modern astronomy is often divided into pre- and post-Hubble eras due to Hubble's overwhelming influence. Since its launch, Hubble has produced over 15,000 papers, the most from a single instrument. I am confident JWST will surpass that. Although many theoretical studies exist, JWST will succeed in observing the very first stars born in the early universe, which have never been observed before. Evidence that life might exist on planets other than Earth will become a reality through JWST. This will have a significant impact not only in science but also in philosophy and religious studies. Along with these results, many new discoveries previously unknown will be made, prompting the establishment of new supporting theories. Until now, astronomy and astrophysics have been fields where theory inspired observations; going forward, JWST's observational results will lead and advance theory.

A simulated image assuming JWST is fully deployed in space. Photo by NASA

-You hold an important position; what challenges or rewarding experiences have you had?

△Since my previous research aligns well with my role in the JWST team, I have not faced major difficulties overall. As I am not an optics specialist, I have put considerable effort into learning optics since joining the JWST team. Because JWST is a globally watched project, those involved, especially the commissioning team, felt immense pressure and responsibility. We worried about what would happen if even one or two key performance factors of the telescope failed to meet targets. Fortunately, all processes proceeded almost perfectly, and the telescope's performance exceeded expectations, giving all team members great satisfaction. Personally, from early February to late June after JWST's launch, I experienced the busiest period of my life. I found it rewarding to creatively solve problems beyond my main responsibilities during commissioning by applying my expertise. When optical instrument teams encountered various issues, I proactively offered help and was fortunate to resolve problems quickly several times.

Mission statement inside the Korea Astronomy and Space Science Institute. Reference photo. Not directly related to the article.

-What is the international evaluation of Korea's astronomy and space research and development?

△Korea is actively participating as a partner in the Giant Magellan Telescope (GMT). With the successful launch of the Nuri rocket and its own lunar exploration efforts, Korea is emerging as a space power. As these successful projects accumulate steadily, Korea's status will rise significantly. If possible, boldly participating in large-scale projects like JWST in the future would greatly help Korea leap forward in astronomy and space development.

-What message would you like to give to Korean youth dreaming of astronomy or space?

△Decades ago, astronomy and space science were often seen as unrealistic fields. Now, the 'era of space' is opening, and these fields are among the most promising sciences. Korea is now on the upward growth curve of astronomy and space science. Even more positively, Korea produces and consumes a substantial amount of high-quality scientific content, which is increasing. If children and youth maintain continuous interest and passion for astronomy and space science news worldwide, their dreams will soon become reality. If they approach space not just as a playground for imagination but as a laboratory for scientists, it will better nurture their dreams.

*Dr. Sangmo Son was born in Seoul in 1975 and completed his master's degree in Astronomy and Space Science at Yonsei University. In 2000, he went abroad to earn his Ph.D. at Virginia State University in the USA. After working as a commissioned senior researcher at the Korea Astronomy and Space Science Institute and a researcher at the California Institute of Technology, he currently works as a senior researcher on the JWST team at the Space Telescope Science Institute (STScI) in the USA. He resides in Baltimore, Maryland, with his wife and two children.