Theme: Galaxy Evolution

 

Text, Viewspace. The show will continue in 15 seconds. Coming up: Discover how galaxies change over time. 

 

The timer at top right counts down from 15 seconds. 

 

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The text appears on a background of stars which move slowly towards and past us. 

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 Large Earth in the foreground, small Sun in the background. 

Text, We live on a planet that orbits a single star. 

The Milky Way galaxy from the side. 

Text, This star is just one of about 200 billion stars in our galaxy, the Milky Way. 

The Milky Way galaxy from the top. It zooms away into the distance with other galaxies. 

Text, The Milky Way is just one of the hundred billion or so galaxies in the universe. 

Endless galaxies zoom by. 

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 Top left, a black and white picture of a minotaur. Top right, a color picture of a galaxy. 

Text, MYTH versus REALITY 

Myth side 

Text, Galaxies shine only in visible light. 

Reality side 

Text, Galaxies emit different types of radiation. Most types of light are invisible to us. Detecting other types of radiation, such as infrared light, X-rays, and ultraviolet light, provides more information and allows us to better understand what is happening inside galaxies. 

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 Many galaxies hang in space above the edge of a planet. 

Text, at-a-GLANCE. GALAXY EVOLUTION. 

A white and pink spiral galaxy. 

Text, VISIBLE LIGHT. By observing infrared light, we notice details of galaxies we would otherwise miss. INFRARED LIGHT. 

The galaxy in infrared is green and white with large pink gas clouds. 

Text, Hubble Image, Spiral Galaxy M101. VISIBLE LIGHT. Spitzer Image, Spiral Galaxy M101. INFRARED LIGHT. In visible light, bright stars dominate the view. In infrared light, warm dust and gas clouds are more prominent. 

Some objects, like cooler stars, also glow more brightly in infrared light than in visible light, and we need to detect infrared light to study them. 

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 Dense clusters of stars in dark red gas and dust. 

Text, Center of Milky Way. INFRARED LIGHT. The Hubble and Spitzer Space Telescopes teamed up to take this picture of the center of our Milky Way Galaxy with their infrared cameras. 

Dust in the Milky Way's core hides much of this view in visible light, but infrared light penetrates most of the dust. 

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An image of space filled with shining stars and spiral-shaped clouds of galaxies. Text, Galaxies are where the action happens in our universe, islands of motion and change in the vastness of space.

 

Within galaxies, most stars live out their lives -- bursting to life, evolving over millions to billions of years, dying violently or slowly. An image of a nebula formed of reddish clouds surrounding a cluster of bright blue white stars.

 

Text, To understand the universe we must understand galaxies. Variously shaped galaxies appear and fade into the background.

 

Other galaxies are too far away for us to reach.

 

Even if we could travel at the speed of light it would still take us 2.5 million years to reach the closest large galaxy, Andromeda. An image of a disk-shaped galaxy with cloudy arms spiralling out from a bright glowing white center.

 

Text, so we must study galaxies from afar.

 

A computer simulation of glowing objects spinning and colliding in darkness. Text, Our understanding is also complicated by time. Galaxies grow and evolve over billions of years -- too slowly for us to observe the changes happening in real time.

 

Fortunately, we can see galaxies as they were at different times in the past.

 

An illustration of many galaxies arranged in transparent layers. The closest layer is labeled light from nearby galaxies. The most distant layer is labeled light from distant galaxies. Text, Light moves quickly but it still takes time to travel through space. Arrows move from the distant to the nearby galaxies.

 

Text, Light from more distant galaxies takes longer to reach us. The arrow from the most distant galaxies continues to move while the closer arrow has stopped.

 

Text, When we capture this light we see galaxies as they appeared with that light started traveling. For distant galaxies, we see them as they were billions of years ago. Images of small galaxies in spiral, disk, or dot shapes and blue, red, and yellow colors.

 

Distant developing galaxies appear as tiny dots. Nearby developed galaxy appears as a large spiral. Text, by looking at different distances, we can observe galaxies at different ages and stages of development.

 

An animation of waves of light moving from a galaxy to earth. Text, But as light travels through the expanding universe, it become stretched by the expansion of space.

 

Visible light changes to infrared light. The light wave turns red as it approaches earth.

 

Text, to see distant early galaxies we must look for this infrared light. A nebula spins in the background.

 

Infrared light is invisible to our eyes but not to NASA's James Webb Space Telescope.

 

An animation of the telescope unfolding itself in space, expanding two long arms in the front and back and stretching two panels open to the sides, forming a reflective silver diamond shaped surface under a panel of golden hexagonal plates that unfold to form a disc framed by long rods that connect at a point. Text, Webb is the largest and most sensitive infrared space telescope ever built. With its position far from Earth and its giant mirror, Webb will capture infrared light never seen before.

 

The telescope near a red galaxy. Text, its powerful infrared vision opens up previously undiscovered realms of the universe.

 

A point flashes bright purple and white on a black background. Text, Webb can observe the first galaxies flickering to life after the big bang.

 

An image of space filled with galaxies. Text, Webb now turns its gaze on the universe's most distant galaxies, the tiny galaxy building blocks that became the graceful spirals and glowing ellipticals we know today.

 
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A red, white, and black elliptical galaxy.

 

Text, Centaurus A is an elliptical galaxy.

 

Elliptical galaxies take their name from their rounded shape.

 

An orange, white, and black elliptical galaxy.

 

Text, They are thought to form from merging galaxies.

 

Text, VISIBLE LIGHT. Infrared images reveal a spiral galaxy that was digested by Centaurus A. INFRARED LIGHT.

 

Centaurus A in infrared is an oblong galaxy of red dust with a bright red spiral galaxy in its center.

 

Text, Infrared vision can see through Centaurus A's thick dust lanes...

 

to the galactic remnant within.

 
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Top left, a black and white picture of a minotaur. Top right, a color picture of a galaxy.

 

Text, MYTH versus REALITY

 

Myth side

 

Text, We can study other galaxies by visiting them.

 

Reality side

 

Text, Other galaxies are too far away to visit. Even if you could travel at the speed of light, it would take millions to billions of years to reach most other galaxies. The closest galaxies to our own Milky Way are dwarf galaxies thousands of light-years away. We study other galaxies from afar, using powerful space telescopes like Hubble, Chandra,  and Webb.

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 A white disk of a galaxy seen from the edge. A bump in the middle forms the core. 

Text, VISIBLE LIGHT. The Sombrero Galaxy, 28 million light-years away, is a striking example of a spiral galaxy seen nearly edge-on from Earth. 

VISIBLE AND INFRARED LIGHT. Infrared observations pick up hidden features, like the bright, smooth ring of dust encircling the galaxy, shown in red. 

The galaxy in infrared has a blue center disk and red ring around the circumference. 

Text, The glow in the center of the galaxy comes from material swirling around the galaxy's huge central black hole.