The James Webb Space Telescope is a 21st-century marvel: the largest and most sophisticated space telescope ever built, operating over a million miles from Earth. By observing in infrared light, invisible to the human eye, Webb can discern the faint, ancient glow of the first stars and galaxies after the Big Bang; identify life-supporting gases in the atmospheres of planets orbiting other stars; and pull back the veil on star-forming regions hidden within thick clouds of interstellar dust. It is the most powerful astronomical tool ever built—and our deepest look yet into cosmic origins. In Experiencing James Webb: The Invisible Universe Revealed, astrophysicist Sarah Rugheimer presents a clear, engaging introduction to Webb’s science, engineering, and discoveries in 12 beautifully illustrated half-hour lectures. The course surveys Webb’s most important scientific findings and includes a full lecture on how to access Webb images online and experiment with free image-processing tools, learning how astronomers extract scientific meaning from raw data. You’ll also discover how Webb’s gold-coated segmented mirror functions as a single ultra-precise instrument, why the telescope operates a million miles from Earth in extreme cold, and how infrared astronomy lets us see the early universe as it was billions of years ago—making Webb, in effect, the ultimate time machine.
Experiencing James Webb: The Invisible Universe Revealed
Trailer
01: The Mission of the James Webb Space Telescope
The James Webb Space Telescope is the most ambitious and powerful telescope ever built. Begin by surveying its scientific goals, learning why they require observations in the infrared part of the spectrum. Then, compare Webb to earlier space telescopes, especially the Hubble. Also, explore how astronomers use false color to make sense of radiation that is literally invisible to the human eye.
02: Building and Launching the Telescope
Unlike the Hubble Space Telescope, which orbits a few hundred miles above Earth, Webb operates nearly a million miles away, far beyond the reach of any repair mission. Survey the engineering challenges involved in building, launching, and deploying such a machine. Also, study Webb’s suite of instruments designed to see the universe’s earliest galaxies and probe the atmospheres of distant exoplanets.
03: Achieving the Milestone of “First Light”
Webb’s initial observation was an ordinary star used to calibrate its optics. However, its first public release was a spectacular look into the most distant regions of the cosmos—the Webb Deep Field—surveying the same patch of sky previously imaged by Hubble but revealing vastly more distant and ancient galaxies. Also, explore other early Webb images, from dying stars to nearby colliding galaxies.
04: Seeing the Earliest Objects in Our Universe
Take a tour of the most distant objects in the universe, revealed for the first time by the Webb Space Telescope. Because light travels at a finite speed, we see these infant galaxies as they were when the universe was only a few hundred million years old, during the earliest era of star formation. They have startled astronomers, appearing larger, brighter, and more evolved than theory predicted.
05: Galaxies, Dark Matter, and Black Holes
Delve into the dark side of the universe: dark matter and black holes—phenomena that emit no light at all but reveal themselves through their effects on luminous matter. Webb’s infrared vision allows it to trace how galaxies grow and cluster under dark matter’s gravitational influence. Learn how the telescope is also transforming the study of supermassive black holes at the centers of galaxies.
06: New Insights into Stars and Dark Energy
Survey Webb’s most breathtaking images, from star-forming regions to glowing planetary nebulae. Then, explore how the telescope’s infrared observations are refining the cosmic distance ladder, strengthening the evidence for dark energy. Close with speculation about “dark stars,” hypothetical hybrids of ordinary and dark matter, inspired by Webb’s views of distant, brilliant point-like sources.
07: Searching for Life in the Universe
If life exists elsewhere in the universe, it is most likely to arise on worlds with liquid water, temperate conditions, and atmospheres rich in molecules such as water vapor, carbon dioxide, and methane. Webb is the most powerful instrument for probing the atmospheres of planets orbiting other stars. Learn how astronomers find these exoplanets and what Webb is already revealing about them.
08: Examining Exoplanets
Investigate Webb’s first-ever measurements of the atmospheres of rocky, Earth-sized exoplanets. Many orbit small, cool M-dwarf stars—common in the galaxy but prone to violent stellar flares that can strip away planetary atmospheres, posing a challenge for any life. Also study the nearby TRAPPIST-1 system, just 40 light-years away, and what Webb’s observations reveal about possible habitability.
09: Using Webb to Investigate Our Solar System
Webb’s unrivalled optics take us to the farthest reaches of the universe, but they also let us explore worlds in our own backyard. Journey through the Solar System, from Neptune—where infrared views reveal features Voyager 2 missed in 1989—to Uranus, Saturn, Jupiter, and Mars, plus icy moons such as Enceladus and Europa, whose hidden oceans of liquid water raise intriguing possibilities for life.
10: How Webb Could Detect Life
Webb is the first telescope able to probe exoplanet atmospheres for signs of life. Contrast habitability—the baseline conditions for life as we know it—with biosignatures, the chemical clues life might leave behind. Then, see how claims for biosignatures in the atmosphere of Venus may have led astronomers astray, underscoring how difficult this problem is at the far greater distances to exoplanets.
11: Processing Your Own Webb Images
You don’t have to be an astronomer to access data from Webb and process it yourself—creating beautiful images while learning the finer points of cosmic structure. This lecture walks you through every step, from logging onto the archive and selecting a target to downloading observations and using free software to process the data. Your practice subject is the stunning Pillars of Creation in M16.
12: The Telescopes of the Future
Webb may seem like the be-all and end-all of telescopes, but more observatories are in the works—both in space and on Earth. Close the course by surveying these coming attractions, which will sharpen our views of exoplanets, distant galaxies, and the large-scale structure of the universe. A central goal is extending the search for life beyond Earth in a universe we are just beginning to explore.
Overview Course No. 10580
About
Sarah Rugheimer is an astrophysicist and Chancellor’s Fellow at the University of Edinburgh. She earned her PhD in Astrophysics at Harvard University. A passionate advocate for engaging the public in science, she has received the Barrie Jones Award from the Astrobiology Society of Britain, the Caroline Herschel Prize Lectureship, and the British Science Association Rosalind Franklin Award Lectureship. Her TED Talk “The Search for Microscopic Aliens” has received nearly 2 million views.
