James Webb Space Telescope Discoveries!

UCSB Physics Professor Roger Freedman held our attention three years ago as he explained the wonders and understanding that the James Web Space Telescope (JWST) would give us. He was back speaking to the Humanist Society again with an update on what JWST is already showing us.

The title of his talk:

“From the Solar System to the Most Distant Galaxies: 2 ½ Years of Discoveries with the James Webb Space Telescope”

Humanist Society President Judy Flattery began with how this talk is relevant to Humanism. From The Affirmations of Humanism by Paul Kurtz:

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We are committed to the application of reason and science to the understanding of the universe and to the solving of human problems.

We believe that scientific discovery and technology can contribute to the betterment of human life.

We are citizens of the universe and are excited by discoveries still to be made in the cosmos.

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Full disclosure: Exploring and understanding the wonders of our universe sits at the top of my list of what gives meaning to life.

Freedman noted that he would do the talk in reverse order from the title, starting with distant galaxies, then moving closer to home.

JWST is an international collaboration, run through the Space Telescope Science Institute, which is in Baltimore. In collaboration with ESA, the European Space Agency.

JWST sees in the infrared (IR) and Freedman explained how this compares to human vision. The electromagnetic spectrum includes many forms of energy. Each form of energy is distinguished by its wavelength. Visible light has a wavelength just below one millionth of a meter. We call this a micrometer (formerly micron).

JWST can see from the middle of the visible light spectrum on up beyond 100 micrometers. If we were talking about sound, we would say that the human range of vision is just one octave (a factor of two in range). Whereas JWST covers about six octaves.

Infrared is the energy radiated as heat in everyday life. He showed us a photo he took with a FLIR infrared camera, showing how recently parked cars radiate from their hoods. FLIR is a local infrared imaging company.

JWST is by far the largest space telescope ever. Its mirror is a collection of 18 smaller mirrors, totaling 6.5 meters in diameter. Far larger than the two meter Hubble telescope mirror. Bigger means two things: Seeing dimmer objects. And seeing things in more detail.

Hubble orbits in low Earth orbit. In contrast, JWST orbits a point called L2 that is far beyond the moon. Which means there is no way to service it, as was done once for Hubble.

On to the discoveries. Starting with galaxies. The universe has been expanding ever since the Big Bang 13.7 billion years ago. Imagine a rubber sheet being stretched with spots on it. The spots get further away from each other.

One consequence: Light also gets stretched out. What may have started out as visible light gets stretched to be the longer wavelengths of infrared. Which is why the JWST comes in handy!

The further out in space we look, we are also looking further back in time. Because it takes time for the light to get to us over vast distances.

The first 400,000 years after the Big Bang, the universe was opaque to light. The goal is to look back as far as possible to that 400,000 year old limit.

Time can be measured in terms of “red shift”. The factor that light is stretched toward the red or infrared. The factor is called “z”. The record so far for observations? A z of 14.32, corresponding to 13.52 billion years ago. When the universe was just 285 million years old.

It was a big surprise to find that there already was a galaxy at this early time. It was 1600 light years across. Compared to our own Milky Way, which is 87,400 light years across.

It seems that most galaxies have a supermassive black hole at their centers. Here is an artist’s rendition.

The supermassive black hole at the center of our galaxy is in the constellation Sagittarius. Freedman showed a video clip of the extreme orbits of stars surrounding this black hole.

He also showed us a radio telescope image of the area around this black hole. As matter falls into the black hole it also emits x-rays, which are of very high energy and short wavelength.

Since it should take time for matter to accumulate into a black hole, it was expected that very distant (very early) galaxies should have small black holes. JWST discovered this is not true. Some of these early galaxies have big black holes! Which means that these black holes may have been seeded from really big gas clouds collapsing to black holes in the early universe. Freedman hopes that we have a better explanation by the next time he talks to us. He said we need “multi-messenger” astronomy, done at a variety of wavelengths.

At this point, Freedman came much closer to home. To Jupiter’s moon Europa. Europa looks very different from our moon, even though it is a similar size. Notably, Europa is missing the craters seen on our moon. This would imply something is reshaping the surface of Europa. On Earth, geological activity reshapes the surface. How could this be happening on such a small body?

Io, Europa and Ganymede are Jupiter’s three inner moons, named for the three lovers of Jupiter in mythology. These three moons move in synchrony. For each orbit Ganymede makes, Europa makes exactly two orbits. These three moons tug on each other rhythmically. As if you were squeezing putty in your hand. These tidal forces heat up Europa.

Europa is mostly water and ice. Just as we have volcanoes on Earth, Europa has “volcanoes” of water and ice. With all of this liquid water, could there be life below the surface of Europa? Life on earth needs carbon. Maybe some comes up in Europa’s volcanoes. We also see salt on Europa.

JWST was able to take a low resolution image of Europa. Not nearly as good as a space probe could do. But it was able to detect carbon dioxide on Europa due to fluorescence in the infrared. In the Tara Regio area of “chaos terrain”. (Tara Regio means High Kings in Celtic mythology.)

In 5-6 years we will have an update. The Europa Clipper space probe was launched in October 2024. It will arrive at Jupiter in April 2030. Thanks to HSSB Board member Gary Noreen, some of us got to see the Europa Clipper in its final stages of assembly at the Jet Propulsion Laboratory.

In between distant galaxies and our solar system are regions of star and planet formation. One such region called “The Pillars of Creation” is widely known from a stunning Hubble image. It is in the Eagle Nebula of our galaxy, 6500 light years away. JWST not only gave us a more detailed view of this nebula. It was also able to see through the molecular clouds of mostly hydrogen with its infrared sensors.

In the middle of the sword of the Orion constellation is a fuzzy blob called the Orion Nebula. It is 1340 light years from us. Another area of active star formation. It puts out a lot of ultraviolet light. Which fluoresces to visible light. Stars in this region are only 300,000 years old. Compared to 4.6 billion for our sun. A chance to see a baby picture of something like our grown up sun.

JWST is able to see solar systems forming from vast clouds of matter. Far bigger than our solar system. JWST also offered a surprise: Planets orbiting each other with no star at all!

These planets range from half the mass of Jupiter to 7 times the mass of Jupiter. Called Jupiter Mass Binary Objects (JuMBOs). Little is understood of how these form and why they form in pairs.

How can we see them if no star is present to illuminate them? Because these planets are mostly gas that is slowly contracting. As it contracts, it heats up. As when a bicycle pump heats up as you compress the air inside. This bit of heat is detected by JWST as infrared light. No one expected to see these objects.

To keep up with the latest JWST images and research, go to https://esawebb.org/

For more information about upcoming events with the Humanist Society of Santa Barbara or to become a member, please go to https://www.sbhumanists.org/

== Robert Bernstein