
Mosaic Title (Row 1, Box 1)

Row 1, Box 1
There are several different kinds of galaxies, including ellipticals, spirals and lenticulars, and they are characterized by their shape. At (x:93, y:83), you can see a good example of a lenticular galaxy, seen from the side.
Mosaic Title (Row 1, Box 2)

Row 1, Box 2
In this image you can see examples of both principal types of galaxies, spirals and ellipticals. Spirals generally live in less dense areas, where they have not been re-shaped by neighboring galaxies.
Mosaic Title (Row 1, Box 3)

Row 1, Box 3
In this image you can see examples of two types of galaxies, spirals and ellipticals. Spirals generally live in less dense areas, where they have not been re-shaped by neighboring galaxies.
Mosaic Title (Row 2, Box 1)

Row 2, Box 1
The single points of light in this image, including the objects with cross-like diagonal patterns, are bright stars in our Milky Way galaxy, while those objects that seem to have shapes are other galaxies. The star at (x:18, y:56) is billions of times smaller than the galaxy to its left, at (x:2, y:45). It is also light years closer to the camera.
Mosaic Title (Row 2, Box 2)

Row 2, Box 2
The red, blue and green flecks in this image are cosmic rays – high-energy particles that pass through the camera, leaving a trace. Those will be removed from the image before scientists study the data.
Mosaic Title (Row 2, Box 3)

Row 2, Box 3
Over billions of years, diffuse clouds of cold molecular gas, intermingled with dark matter, are condensed by gravity. During that process, stars form within that structure, creating what we know as galaxies. As you can see in this image at (x:61, y:56), galaxies are brighter in the center than at the edges, since most of the stars are clumped there.
Mosaic Title (Row 2, Box 4)

Row 2, Box 4
Stretching throughout the universe is a cosmic web made up of the galaxies you see here, which the Dark Energy Survey will study. The large-scale pattern of matter in the universe, and how that pattern changes over time, is one of the factors that tells us how the expansion of the universe is changing.
Mosaic Title (Row 3, Box 1)

Row 3, Box 1
What will the Dark Energy Survey actually survey? Over five years, scientists will capture images of 300 million galaxies, 100,000 galaxy clusters, and 4,000 new supernovae.
Mosaic Title (Row 3, Box 2)

Row 3, Box 2
The star at (x:25, y:73) in the foreground is obscuring light from distant galaxies. The Dark Energy Camera’s sensitivities – and the algorithms used to process the camera’s images – must be sensitive enough to differentiate these objects.
Mosaic Title (Row 3, Box 3)

Row 3, Box 3
You can see a cluster of galaxies in the upper middle right portion of this image. We know these galaxies are in a distant cluster because they share a similar hue. Most galaxies in clusters are elliptical and red in color, like these.
Mosaic Title (Row 3, Box 4)

Row 3, Box 4
Here you see a spiral galaxy at (x:50, y:61). The extended arms of this galaxy are barely distinguishable. Most galaxies that are not near others tend to be spiral galaxies.
Mosaic Title (Row 3, Box 5)

Row 3, Box 5
The Dark Energy Camera is intensely sensitive to red light. This will help determine how many stars are forming in each galaxy it photographs. Red galaxies have many older stars, and fewer that are newly forming. (They’re often referred to as “red and dead” galaxies.) It will also help us see more distant galaxies, due to a phenomenon known as red shift.
Mosaic Title (Row 4, Box 1)

Row 4, Box 1
Cosmic rays, which you can see throughout this image as red, blue and green flecks, are typically formed outside our solar system, and are thought to originate from supernovae or from interactions occurring near supermassive black holes.
Mosaic Title (Row 4, Box 2)

Row 4, Box 2
Here we see a huge lenticular galaxy, part of the Fornax cluster of galaxies, located about 60 million light years away. We know this is part of the Fornax cluster since it has the same color as the other galaxies you will see in the foreground of other fields of this snapshot. The color tells us the distance from the camera.
Mosaic Title (Row 4, Box 3)

Row 4, Box 3
Are you marveling at the crispness of this photo? The Dark Energy Camera captures images at a resolution of 570 megapixels. Your average digital camera ranges from 10 to 20 megapixels.
Mosaic Title (Row 4, Box 4)

Row 4, Box 4
The Dark Energy Camera is the most powerful digital imaging instrument in the world. It was built at the Fermi National Accelerator Laboratory, and then mounted on the 4-meter Victor M. Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile.
Mosaic Title (Row 4, Box 5)

Row 4, Box 5
At (x:44, y:31) you will see two galaxies that appear to be incredibly close. Dark Energy Survey scientists will use color and intensity of light to differentiate nearby galaxies.
Mosaic Title (Row 4, Box 6)

Row 4, Box 6
Here we can see an example of a spiral galaxy seen face-on at (x:39, y:38), and one seen edge-on at (x:93 ,y:9).
Mosaic Title (Row 5, Box 1)

Row 5, Box 1
At (x:31, y:13) you can see an optical artifact – the light is reflecting off of multiple surfaces within the camera, causing a distortion of the image. These are a fact of life for astrophysicists, and since they can’t be removed from the image as easily as cosmic rays, they sometimes just need to be ignored.
Mosaic Title (Row 5, Box 2)

Row 5, Box 2
What you’re looking at is a tiny portion of the expanse of sky the Dark Energy Survey will photograph over five years. Scientists on the survey will systematically map one-eighth of the sky – roughly 5,000 square degrees. The prominent galaxy in the lower left is NGC 1382, an elliptical galaxy in the Fornax cluster.
Mosaic Title (Row 5, Box 3)

Row 5, Box 3
The galaxy partially cut off at the bottom of this image is NGC 1374, an elliptical galaxy in the Fornax cluster. Most of the galaxies that the Dark Energy Survey will observe were born billions of years ago. During their lifetimes, they have undergone internal transformations, such as the flare-up of supernovae, as well as the effects of their environment,like the gravitational impact of neighboring galaxies.
Mosaic Title (Row 5, Box 4)

Row 5, Box 4
Many of the galaxies in this image appear blue, like those at (x:78, y:27) and (x:60, y:53). Galaxies that appear blue tend to be younger, and full of newly forming stars.
Mosaic Title (Row 5, Box 5)

Row 5, Box 5
In the upper left of this image, you will see a small galaxy cluster made up of yellow-orange galaxies. The Dark Energy Survey will use clusters of all sizes, from tens to thousands of galaxies, counting the number of clusters of a given size. The distribution of sizes provides one of the windows into the nature of dark energy.
Mosaic Title (Row 5, Box 6)

Row 5, Box 6
Light coming from distant objects passes through many layers of Earth’s atmosphere before finally reaching the telescope at Cerro Tololo Inter-American Observatory in Chile. The relatively calm Chilean atmosphere allows for better focus in these images, giving us the exquisite resolution you see here.
Mosaic Title (Row 5, Box 7)

Row 5, Box 7
Caption text goes here. Descriptive caption text.
Mosaic Title (Row 6, Box 1)

Row 6, Box 1
At any time, a supernova could erupt from any of the galaxies in this image. Individual supernovae can completely outshine a galaxy for a short period of time before burning out. The Dark Energy Survey will measure roughly 4,000 of these new supernovae.
Mosaic Title (Row 6, Box 2)

Row 6, Box 2
The Dark Energy Survey will capture bright elliptical galaxies (like the one at x:48, y:47) and bright spiral galaxies (like the one at x:44, y:59). It will also capture images of faint, distant galaxies. Seeing far away and deep into the past is critical for understanding the potentially evolving nature of dark energy.
Mosaic Title (Row 6, Box 3)

Row 6, Box 3
In this image you can see a beautiful lenticular galaxy, NGC 1381, at (x:24, y:65). The varying orientations of galaxies pose a challenge for measuring their intrinsic shapes. When any kind of matter appears between the galaxy and us, light will bend around it and the image will appear distorted. Recovering the original shape from this distorted image is an important step in measuring dark energy.
Mosaic Title (Row 6, Box 4)

Row 6, Box 4
Before studying them, scientists will remove the red, blue and green flecks that signify cosmic rays darting through these images. For each part of the sky observed, two snapshots are taken, and whatever does not appear in both images is likely caused by cosmic rays, and is automatically removed. The large galaxy in the upper left is NGC 1375, a spiral galaxy.
Mosaic Title (Row 6, Box 5)

Row 6, Box 5
Since the Dark Energy Camera can see light from stars billions of light years away, it can effectively peer into the past, and map out the expansion of the universe. Scientists know that the universe continues to expand faster and faster, and dark energy is the force believed to be causing that acceleration.
Mosaic Title (Row 6, Box 6)

Row 6, Box 6
The universe was born nearly 14 billion years ago in a conflagration that happened exactly where you’re sitting. The Big Bang occurred in the most distant reaches of the universe, and its effects are still felt, since the universe continues to expand, faster and faster.
Mosaic Title (Row 6, Box 7)

Row 6, Box 7
Optical artifacts can form when light from stars reflects off of multiple surfaces within the camera. We can see the symmetry of the camera here – the optical artifact at (x:60, y:44) is oriented to the right, the mirror image of the artifact in Row 5, Box 1.
Mosaic Title (Row 7, Box 1)

Row 7, Box 1
Another bright galaxy from the Fornax cluster has been cut in half by the gap between this field and the next. When this happens, the two Charged Coupled Devices that capture the images must be calibrated to ensure they are capturing light at the same rate.
Mosaic Title (Row 7, Box 2)

Row 7, Box 2
The Dark Energy Survey will search for patterns in the cosmic web (see Row 2, Box 4) at different points in cosmic time. The way this pattern changes in time provides clues to the changing nature of dark energy.
Mosaic Title (Row 7, Box 3)

Row 7, Box 3
The elliptical galaxy you see at (x:56, y:77) is NGC 1379, also a member of the Fornax cluster. It appears to be spherical in shape – it could also be a cigar-shaped galaxy we are seeing edge-on. If it is a sphere, its shape has been determined by billions of years of gravitational interactions with its cluster neighbors.
Mosaic Title (Row 7, Box 4)

Row 7, Box 4
While some of the cosmic rays in this image can be seen as red, blue or green streaks, some have encountered the Dark Energy Camera head-on. Those appear in the image as small red dots, as you can see at (x:66, x:69). Larger red dots that appear as smudges (x:35, y:69) are actually very distant galaxies, and the camera is designed with particular sensitivity to their red light.
Mosaic Title (Row 7, Box 5)

Row 7, Box 5
The Dark Energy Camera’s intense sensitivity to red light makes images like this possible. In each snapshot, it will be able to see light from up to 8 billion light years away.
Mosaic Title (Row 7, Box 6)

Row 7, Box 6
In this image, you can see multiple types of galaxies, including a face-on spiral at (x:70, y:2), several edge-on spirals to the right of that at (x:89, y:7), and an elliptical at (x:90, y:43).
Mosaic Title (Row 7, Box 7)

Row 7, Box 7
Dark Energy Survey scientists will use pictures like this one to study the bending of light, another method to zero in on dark energy. The fight between gravity and dark energy shapes the lumps of dark matter in the cosmos, and light bends around those lumps, causing galaxies to appear distorted in the images from the camera. The survey will measure the shapes of 200 million galaxies to further examine this phenomenon.
Mosaic Title (Row 8, Box 1)

Row 8, Box 1
At (x:21, y:82) you can see another elliptical galaxy, NGC 1404. We know it is in the Fornax cluster because it shares similar colors with the galaxies nearby, and it is a similar distance away from us. These galaxies in the Fornax cluster have similar apparent sizes when viewed through the Dark Energy Camera.
Mosaic Title (Row 8, Box 2)

Row 8, Box 2
At (x:52, y:83) you can see a great example of a face-on spiral galaxy. Spirals are thought to originate from density waves, similar to the pressure waves that carry sound from your speakers to your ears. For more information on galaxy morphologies, visit this link: http://skyserver.sdss.org/dr1/en/proj/advanced/galaxies/tuningfork.asp
Mosaic Title (Row 8, Box 3)

Row 8, Box 3
The Dark Energy Camera was built with five precisely shaped lenses, the largest of which is nearly a yard across. Together, they provide a sharp and clear image across the camera’s entire field of view. Those images are captured on 62 “charged coupled devices.” What you are looking at now is the view from just one of those CCDs.
Mosaic Title (Row 8, Box 4)

Row 8, Box 4
One method the Dark Energy Survey will use is counting galaxy clusters. While gravity pulls galaxy clusters together, dark energy pushes them apart. Counting the number of galaxy clusters at different points in time will (ahem) shed light on this cosmic competition between gravity and dark energy.
Mosaic Title (Row 8, Box 5)

Row 8, Box 5
The Dark Energy Survey will detect roughly 4,000 new supernovae, which could occur at any time from any galaxy, including the ones in this image. Supernovae are precise distance markers, which act as buoys in the fabric of space-time, tracing the expansion history of the universe.
Mosaic Title (Row 8, Box 6)

Row 8, Box 6
Stars, through the process of fusion in their cores, burn hydrogen and lighter elements into heavier elements, like calcium and silicon, which we see in our everyday world. When a star goes supernova, it expels these heavier elements into the surrounding environment, where new stars and planets like ours can form. We are, quite literally, made of stars.
Mosaic Title (Row 9, Box 1)

Row 9, Box 1
In the classification scheme of galaxies, the barred spiral is another discrete category. An example of a barred spiral galaxy can be found at (x:4, y:6), and a non-barred spiral can be found at (x:91, y:61). Differing amounts of activity in the center of the galaxy have formed the dust, gas and stars of the former into a bar-like shape.
Mosaic Title (Row 9, Box 2)

Row 9, Box 2
Another Fornax cluster galaxy, NGC 1389, can be seen at (x:32, y:93). It is extremely bright, and will obscure most of the light from objects behind it. While much of that light will not be usable, through our understanding of the brightness profiles of these kinds of galaxies, we can still find ways to extract information about the objects behind the galaxies.
Mosaic Title (Row 9, Box 3)

Row 9, Box 3
The bright foreground object at (x:40, y:11) is a star like our sun. Each of the galaxies shown here contains billions of these stars, and the Dark Energy Survey will observe hundreds of millions of these galaxies. There are trillions of them in the observable universe.
Mosaic Title (Row 9, Box 4)

Row 9, Box 4
The universe is expanding, and carrying with it the stars and galaxies that send their light to us. As galaxies move away from us, it takes longer for the light to reach us. Some galaxies will be too far away for their light to have reached us. This marks the edge of our observable universe.
Mosaic Title (Row 9, Box 5)

Row 9, Box 5
So will the Dark Energy Camera be able to see dark energy itself? In a word, no. But it will enable scientists to study the expansion of the universe over time, and map out its large-scale structure, which will provide the most precise measurements to date of dark energy’s properties.
Mosaic Title (Row 9, Box 6)

Row 9, Box 6
Even though the term “dark energy” is in the name of the camera and the survey, it’s possible that the results from the five-year experiment will point to something else entirely as the cause of the universe’s accelerating expansion. It’s one of the biggest mysteries of the cosmos, and all answers are on the table.
Mosaic Title (Row 10, Box 1)

Row 10, Box 1
When light is emitted from a celestial object, it must pass through not only empty space but hot plasma within galaxy clusters, intergalactic cold dust, and layers of Earth’s atmosphere before reaching our camera. It also travels a path through space-time that has been warped by intervening matter. It’s a long and arduous journey from the stars to our eyes.
Mosaic Title (Row 10, Box 2)

Row 10, Box 2
You can see another lenticular galaxy, NGC 1386, from the Fornax cluster in the lower left, at (x:9, y:34). Galaxies that have transformed from star-forming spirals to ellipticals have had their cold gas heated by the hot plasma that exists between galaxies in a cluster. This brings to a halt the star formation process and destroys the spiral structure.
Mosaic Title (Row 10, Box 3)

Row 10, Box 3
At (x:18, y:75) you can find another optical artifact, similar to those in Row 5, Box 1 and Row 6, Box 7. Notice that the artifact itself – the red circle – is offset below the star, where the other artifacts were offset to the left and right. That shows the symmetrical feature of the telescope lens.
Mosaic Title (Row 10, Box 4)

Row 10, Box 4
Another pair of very close spiral galaxies can be found at (x:78, y:73). These may appear to be colliding, but one may be hundreds of millions of light years behind the other. By contrast, the Milky Way is only 2.5 million light years from Andromeda, our nearest neighboring galaxy. (We will collide, but not for four billion years.)
Mosaic Title (Row 10, Box 5)

Row 10, Box 5
The clarity of this image is partially due to the placement of the camera. The Dark Energy Camera is mounted on a telescope in the Andes Mountains in Chile, about 2,200 meters (7,200 feet) above sea level. The higher the vantage point, the better the chances of avoiding any atmospheric disruptions that could obscure the images.
Mosaic Title (Row 11, Box 1)

Row 11, Box 1
All the light in this image, whether from an elliptical galaxy, a spiral galaxy or a foreground star, has taken at minimum thousands, and at most billions of years to reach us. When the most distant light we see here left its source, there likely was no Earth – the planet formed a mere four billion years ago.
Mosaic Title (Row 11, Box 2)

Row 11, Box 2
If you like this image, thank the more than 200 scientists from 25 institutions located in six countries around the world. They all helped plan and build the Dark Energy Camera. Like most large physics experiments, this one is global.
Mosaic Title (Row 11, Box 3)

Row 11, Box 3
You are looking at NGC 1365, a spiral galaxy in the Fornax cluster. It is also known as the Great Barred Spiral Galaxy, and it is located 56 million light years away. It has an active galactic nucleus at its core – essentially a supermassive black hole with a disc of hot orbiting matter – which is even brighter than a supernova. It emits high-energy jets of radiation that can affect the entire structure of the cluster.
Mosaic Title (Row 11, Box 4)

Row 11, Box 4
The hunt for dark energy assumes that the current theory of gravity is the correct one. If that turns out to not be the case, then the expansion of the universe could be caused by other factors, and we would need another theory of gravity to explain it. The Dark Energy Survey is also working on modified gravity theories that could replace dark energy.
Mosaic Title (Row 12, Box 1)

Row 12, Box 1
There’s a multitude of fascinating objects in this field, including the magnificent barred spiral galaxy NGC 1369 at (x:11, y:83), the elliptical galaxy at (x:91, y:43) and the two foreground stars at (x:68, y:43) and (x:80, y:18), both of which are faintly displaying optical artifacts.
Mosaic Title (Row 12, Box 2)

Row 12, Box 2
The exploration of dark energy has just begun, and already several theories have been overturned, and new mysteries discovered. If we ever want to learn the truth about our ever-expanding universe, experiments like the Dark Energy Survey are vitally important.
Mosaic Title (Row 12, Box 3)

Row 12, Box 3
All of the images you have been looking at were captured within the last year, while the Dark Energy Camera was put through its paces. The Dark Energy Survey began in earnest on August 31, 2013, and will run for five years.