Physics faculty member discusses significance of James Webb Space Telescope images, technology
Space exploration and scientists’ quest to understand the cosmos received a major jolt earlier this month when the first images from the revolutionary James Webb Space Telescope, or JWST, were shared with the world. The $10 billion telescope is expected to provide new opportunities to scientists and deepen humankind’s understanding of the realm of space. Melissa Halford, a lecturer in Auburn University’s Department of Physics in the College of Sciences and Mathematics, or COSAM, took some time to discuss the transcendent images that recently were released to the public, how the telescope may help us understand the history of our universe and how this latest advancement in astronomy might affect educators’ curriculums going forward.
Can you talk about the significance of the recently released images from the James Webb Space Telescope and what they might tell scientists and researchers about space and the universe?
The first images from the James Webb Space Telescope highlight some of the environments that the telescope will help us learn more about. Subjects of the first five images included a large cluster of galaxies, the atmosphere of a planet outside of our solar system (an exoplanet), a dying star, a small group of interacting galaxies and a region where stars are forming. JWST is sometimes called the successor to the Hubble Space Telescope, or HST, but the two telescopes have some differences that will allow JWST to do science that HST can’t do. One key difference is that the two telescopes observe different wavelengths, or colors, of light. HST primarily observes visible light—the light that human eyes can see—but it also has some capabilities in ultraviolet (wavelengths shorter than violet) and infrared (wavelengths longer than red) light. JWST sees some of the red light that humans see, but most of its work will be at infrared wavelengths longer than those that HST observes. There have been infrared space telescopes before, but none with the sensitivity or resolution that JWST will achieve.
Scientifically, observing the universe at multiple wavelengths is critical because different astrophysical processes emit and absorb different kinds of light. One of the new images shows part of the Carina Nebula, a large gas cloud where stars are being born. Clouds like this one contain dust, which is relatively opaque to visible light and obscures many of the stars in HST’s observations. But this kind of dust is more transparent to infrared light, so JWST can see through it and reveal stars that can’t be seen by HST. Software developer John Christensen created a fun online tool that allows you to see this effect by directly comparing JWST and HST images of the same objects.
A second example of JWST’s capabilities is the exoplanet atmosphere measurement. Astronomers have observed thousands of exoplanets with other telescopes, but never with the sensitivity, wavelength range and resolution of JWST. One of JWST’s primary goals is to aid in the ongoing effort to characterize exoplanets—beyond their existence, what can we learn about the environments on these planets?
The images provided by the $10 billion telescope have been revolutionary and highlight the fact that our knowledge of the cosmos may just be the tip of the iceberg. Is this a reminder that there is infinite room for new discoveries and expansion of our understanding of the known universe?
Yes, the universe is a big and complex place, and we have much more to learn! Astronomy has seen tremendous advances in the last few decades. The ability to launch telescopes into space has allowed astronomers to measure the universe at wavelengths of light that were impossible to see from the ground because they are absorbed by Earth’s atmosphere. Major cosmological discoveries in the 20th century taught us about dark matter and dark energy, which together make up around 95% of the universe, but we still don’t know what they are. The construction of gravitational wave detectors has resulted in the first observations of colliding black holes. It’s only been about 30 years since the first exoplanets were discovered, and we now know of over 5,000 and are learning about the compositions of their atmospheres. JWST is part of the continual effort to push the boundaries of our understanding.
Another key area that JWST will illuminate is the very early history of the universe. If we want to see the first galaxies that ever formed, we need to detect light that has been traveling for more than 13 billion years to reach us. But the universe is expanding, which stretches this light out to longer wavelengths as it travels. Light that was emitted from these first galaxies at visible wavelengths is in the infrared part of the spectrum by the time it gets to us, so we need an infrared instrument like JWST to see it.
How do you think the James Webb Telescope photos affect astronomy instruction at the collegiate level, and will it influence your curriculum in your fall semester astronomy classes?
I think that one of the most exciting aspects of JWST is that it’s difficult to predict how it will affect the field of astronomy. Whenever a new facility with new capabilities observes the universe, many of its discoveries are ones that weren’t predicted or imagined. JWST was designed in part to help answer a few specific questions, such as how the first galaxies formed, but much of what it will do is unknown. When I teach astronomy classes, I like to highlight the fact that astronomy is changing all the time as new discoveries are made. Discussing recent releases from JWST is one way to bring those discoveries into the classroom. As for how it will impact the scientific part of the curriculum, such as what my students will learn about exoplanet atmospheres, I’m looking forward to finding out as new results are announced!
Space exploration has been in the news a great deal in recent years thanks to the exploits of privately owned spaceflight companies like SpaceX, more information being discovered about black holes and multiple missions to Mars. Are we experiencing a new “golden age” of space exploration and discovery?
Recent technological advances have produced incredible astronomical discoveries, and there are certainly many more to come. New technology has also enabled private companies to begin exploring space. I think that there are two ways to look at commercial spaceflight from an astronomical perspective. The first is that, yes, spaceflight is currently difficult and expensive, but a lot of people are hard at work on the problem of making it easier. This effort will likely result in new scientific missions and could do a lot to improve our understanding of the solar system and the universe as a whole.
At the same time, there are reasons for concern. One goal of some spaceflight companies is to launch satellite “constellations,” or groups of many satellites that will bring high-speed Internet to places on Earth that are currently without access. Only a small fraction of the planned satellites have been launched, and they are already impacting ground-based astronomical observations. Astronomers have shared images with streaks of satellites crossing the field of view and impairing their ability to observe scientific targets. This issue was previously relatively minor, but it has the potential to become much worse if expansion of commercial spaceflight isn’t thoughtfully planned.
About Melissa Halford:
Melissa Halford is a lecturer in the Department of Physics at Auburn University. She received her Bachelor of Arts degree in astronomy from Cornell University in 2012 before attending the University of Arizona, where she received her Master of Science in astronomy in 2014 and her doctorate in astronomy and astrophysics in 2018. Her research focuses on star clusters and star formation, specifically looking for variations in populations of stars due to the different environments in which those stars form.
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