Using NASA's Spitzer Space Telescope, astronomers have, for the first time, found signatures of silicate crystals around a newly forming protostar in the constellation of Orion. The crystals are from the olivine silicate minerals known as forsterite, and are similar to those found on the green sand beaches of Hawaii. The data in the graph were taken by Spitzer's infrared spectrograph, which sorts infrared light relative to its color, or wavelength. The characteristic spectral signatures of the crystals are shaded in green. The formation of forsterite crystals requires relatively high temperatures near 1,300 degrees Fahrenheit (700 degrees Celsius). The crystals were not expected to beseen in the cold environment of a newly forming star (minus 280 degrees Fahrenheit or minus 130 degrees Celsius). Astronomers believe that these crystals were created near the protostar and carried up to a cold, collapsing cloud of gas and dust by jets of gas. The crystals are expected to eventually rain back down onto the protostar's planet-forming disk, possibly to be used in the formation of comets.

This image from NASA's Spitzer Space Telescope shows what lies near the sword of the constellation Orion -- an active stellar nursery containing thousands of young stars and developing protostars. Many will turn out like our sun. Some are even more massive. These massive stars light up the Orion nebula, which is seen here as the bright region near the center of the image. To the north of the Orion nebula is a dark filamentary cloud of cold dust and gas, over 5 light-years in length, containing ruby red protostars that jewel the hilt of Orion's sword. These are the newest generation of stars in this stellar nursery, and include the protostar HOPS 68, where Spitzer spotted tiny green crystals in a surrounding cloud of gas.

NASA's Spitzer Space Telescope detected tiny green crystals, called olivine, thought to be raining down on a developing star. An arrow points to the embryonic star, called HOPS-68. It is located in the dark filamentary cloud of cold dust and gas, over 5 light-years in length, located just north of the Orion nebula, which is seen here as the bright region at the bottom of the image.

This artist's conception shows green crystals of olivine raining down on a developing star like cosmic glitter. The crystals were spotted by NASA's Spitzer Space Telescope in a collapsing cloud of gas surrounding an embryonic star called HOPS-68. Stars form out of collapsing clouds. The growing stars feed off the clouds, accumulating more and more mass. Here, HOPS-68 is shown embedded within a large, dark filament of dust and gas. The artwork illustrates how the olivine crystals are suspected to have been transported into the outer cloud around the developing star, or protostar. Jets shooting away from the protostar, where temperatures are hot enough to cook the crystals, are thought to have transported them to the outer cloud, where temperatures are much colder. Astronomers say the crystals are raining back down onto the swirling disk of planet-forming dust circling the star, pictured here as a green fog falling away from the jet.

This artist's conception shows green crystals of olivine raining down on a developing star like cosmic glitter. The crystals were spotted by NASA's Spitzer Space Telescope in a collapsing cloud of gas surrounding an embryonic star called HOPS-68. Stars form out of collapsing clouds. The growing stars feed off the clouds, accumulating more and more mass.

This montage shows three examples of colliding galaxies from a new photo atlas of galactic "train wrecks." The new images combine observations from NASA's Spitzer Space Telescope, which observes infrared light, and NASA's Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because different components of a galaxy are highlighted. The panel at far left shows NGC 470 (top) and NGC 474 (bottom); at top right are NGC 3448 and UGC 6016; at bottom right are NGC 935 and IC 1801. In this representative-color image, far-ultraviolet light from GALEX is blue, 3.6-micron light from Spitzer is cyan, 4.5-micron light from Spitzer is green, and red shows light at 5.8 and 8 microns from Spitzer.

This image shows an example of colliding galaxies from a new photo atlas of galactic "train wrecks". The new image combine observations from NASA's Spitzer Space Telescope, which observes infrared light, and NASA's Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because different components of a galaxy are highlighted. This image shows NGC 3448 and UGC 6016. In this representative-color image, far-ultraviolet light from GALEX is blue, 3.6-micron light from Spitzer is cyan, 4.5-micron light from Spitzer is green, and red shows light at 5.8 and 8 microns from Spitzer.

This image shows an example of colliding galaxies from a new photo atlas of galactic "train wrecks". The new image combine observations from NASA's Spitzer Space Telescope, which observes infrared light, and NASA's Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because different components of a galaxy are highlighted. This image shows NGC 470 (top) and NGC 474 (bottom). In this representative-color image, far-ultraviolet light from GALEX is blue, 3.6-micron light from Spitzer is cyan, 4.5-micron light from Spitzer is green, and red shows light at 5.8 and 8 microns from Spitzer.

This image shows an example of colliding galaxies from a new photo atlas of galactic "train wrecks." The new image combine observations from NASA's Spitzer Space Telescope, which observes infrared light, and NASA's Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because different components of a galaxy are highlighted. This image shows NGC 935 and IC 1801. In this representative-color image, far-ultraviolet light from GALEX is blue, 3.6-micron light from Spitzer is cyan, 4.5-micron light from Spitzer is green, and red shows light at 5.8 and 8 microns from Spitzer.

Eta Carinae is one of the most massive and brightest stars in the Milky Way. Compared to our own Sun, it is about 100 times as massive and a million times as bright. This famed variable hypergiant star (upper center) is surrounded by the Carina Nebula. In this composite image spanning the visible and infrared parts of the spectrum, areas that appear blue are not obscured by dust, while areas that appear red are hidden behind dark clouds of dust in visible light. A study combining X-ray and Infrared observations has revealed a new population of massive stars lurking in regions of the nebula that are highly obscured by dust. Adding these new massive stars to the known massive stars suggests that the Carina Nebula will produce twice as many supernova explosions as previously supposed. Visible light in the blue part of the spectrum from the Digital Sky Survey is represented as blue, near infrared light with a wavelength of 2.2 microns from the Two Micron All Sky Survey (2MASS) is green, and infrared observations from the Infrared Array Camera on NASA's Spitzer Space telescope at 3.6 microns is red.

This artist's conception depicts the Kepler-10 star system, located about 560 light-years away near the Cygnus and Lyra constellations. Kepler has discovered two planets around this star. Kepler-10b is, to date, the smallest known rocky exoplanet, or planet outside our solar system (dark spot against yellow sun). This planet, which has a radius of 1.4 times that of Earth's, whips around its star every .8 days. Its discovery was announced in Jan. 2011. Now, in May 2011, the Kepler team is announcing another member of the Kepler-10 family, called Kepler-10c (larger foreground object). It's bigger than Kepler-10b with a radius of 2.2 times that of Earth's, and it orbits the star every 45 days. Both planets would be blistering hot worlds. Kepler-10c was first identified by Kepler, and later validated using a combination of a computer simulation technique called "Blender," and NASA's Spitzer Space Telescope. Both of these methods are powerful ways to validate the Kepler planets that are too small and faraway for ground-based telescopes to confirm using the radial-velocity technique. The Kepler team says that a large fraction of their discoveries will be validated with both of these methods. In the case of Kepler-10c, scientists can be 99.998 percent sure that the signal they detected is from an orbiting planet. Part of this confidence comes from the fact that Spitzer, an infrared observatory, saw a signal similar to what Kepler detected in visible light. If the signal were coming from something other than an orbiting planet -- for example an indistinguishable background pair of orbiting stars -- then scientists would expect to see different signals in visible and infrared light.

The giant cluster of elliptical galaxies in the center of this image contains so much dark matter mass that its gravity bends light. This means that for very distant galaxies in the background, the clusters gravitational field acts as a sort of magnifying glass, bending and concentrating the distant objects light towards Hubble. These gravitational lenses are one tool astronomers can use to extend Hubbles vision beyond what it would normally be capable of observing. Using Abell 383, a team of astronomers have identified and studied a galaxy so far away we see it as it was less than a billion years after the Big Bang. It is visible as two tiny dots (labelled) on either side of the bright cluster galaxy in the centre. Distant objects seen through gravitational lenses are typically multiply imaged and heavily distorted. Viewing this galaxy through the gravitational lens meant that the scientists were able to discern many intriguing features that would otherwise have remained hidden, including that its stars were unexpectedly old for a galaxy this close in time to the beginning of the Universe. This has profound implications for our understanding of how and when the first galaxies formed, and how the diffuse fog of neutral hydrogen that filled the early Universe was cleared. Acknowledgement: Marc Postman (STScI)

This illustration shows a phenomenon known as gravitational lensing, which is used by astronomers to study very distant and very faint galaxies. Note that the scale has been greatly exaggerated in this diagram. In reality, the distant galaxy is much further away and much smaller. Lensing clusters are clusters of elliptical galaxies whose gravity is so strong that they bend the light from the galaxies behind them. This produces distorted, and often multiple images of the background galaxy. But despite this distortion, gravitational lenses allow for greatly improved observations as the gravity bends the lights path towards Hubble, amplifying the light and making otherwise invisible objects observable. A team of astronomers has used Abell 383, one such gravitational lens, to observe a distant galaxy whose light is resolved into two images by the cluster. The gravitational lensing effect means that astronomers have been able to determine fascinating insights about the galaxy that would not normally be visible even with Hubble or large ground-based telescopes. Among their discoveries is that the distant galaxys stars are very old, meaning that galaxies probably formed earlier in cosmic history than we first thought.

The giant cluster of elliptical galaxies in the center of this image contains so much dark matter mass that its gravity bends light. This means that for very distant galaxies in the background, the clusters gravitational field acts as a sort of magnifying glass, bending and concentrating the distant objects light towards Hubble. These gravitational lenses are one tool astronomers can use to extend Hubbles vision beyond what it would normally be capable of observing. Using Abell 383, a team of astronomers have identified and studied a galaxy so far away we see it as it was less than a billion years after the Big Bang. Viewing this galaxy through the gravitational lens meant that the scientists were able to discern many intriguing features that would otherwise have remained hidden, including that its stars were unexpectedly old for a galaxy this close in time to the beginning of the Universe. This has profound implications for our understanding of how and when the first galaxies formed, and how the diffuse fog of neutral hydrogen that filled the early Universe was cleared. Acknowledgement: Marc Postman (STScI)

NASA's Spitzer Space Telescope took this image of a baby star sprouting two identical jets (green lines emanating from fuzzy star). The jet on the right had been seen before in visible-light views, but the jet at left -- the identical twin to the first jet -- could only be seen in detail with Spitzer's infrared detectors. This left jet was hidden behind a dark cloud, which Spitzer can see through. The Spitzer image shows that both of the twin jets, in a system called Herbig-Haro 34, are made up of identical knots of gas and dust, ejected one after another from the area around the star. By studying the spacing of these knots, and knowing the speed of the jets from previous studies, astronomers were able to determine that the jet to the right of the star punches its material out 4.5 years later than the counter-jet. The new data also reveal that the area from which the jets originate is contained within a sphere around the star, with a radius of 3 astronomical units. An astronomical unit is the distance between Earth and the sun. Previous studies estimated that the maximum size of this jet-making zone was 10 times larger. The wispy material is gas and dust. Arc-shaped bow shocks can be seen at the ends of the twin jets. The shocks consist of compressed material in front of the jets. The Herbig-Haro 34 jets are located at approximately 1,400 light-years away in the Orion constellation.

This image layout shows two views of the same baby star -- at left is a visible-light image, and at right is an infrared image from NASA's Spitzer Space Telescope. Spitzer's view shows that this star has a second, identical jet shooting off in the opposite direction of the first. Both jets are seen in green in the Spitzer image, emanating from the fuzzy white star. Only one jet can be seen in the visible image in red. The second jet is buried behind a dark cloud, and thus cannot be seen in visible-light images. Spitzer's infrared vision was able to show the jet in detail for the first time. Infrared light can penetrate dusty, dense clouds. The Spitzer image shows that both of the twin jets, in a system called Herbig-Haro 34, are made up of identical knots of gas and dust, ejected one after another from the area around the star. By studying the spacing of these knots, and knowing the speed of the jets from previous studies, astronomers were able to determine that the visible jet (to the right of the star) punches its material out 4.5 years later than the counter-jet. The new data also reveal that the area from which the jets originate is contained within a sphere around the star, with a radius of 3 astronomical units. An astronomical unit is the distance between Earth and the sun. Previous studies estimated that the maximum size of this jet-making zone was 10 times larger. The wispy material in both views is gas and dust. Also, in both views, arc-shaped bow shocks can be seen at the ends of the twin jets. The shocks consist of compressed material in front of the jets. The Herbig-Haro 34 jets are located at approximately 1,400 light-years away in the Orion constellation.

The region around the center of our Milky Way galaxy glows colorfully in this new version of an image taken by NASA's Spitzer Space Telescope. The data were previously released as part of a long, 120-degree view of the plane our galaxy (see http://www.spitzer.caltech.edu/images/2680-ssc2008-11a-Spitzer-Finds-Clarity-in-the-Inner-Milky-Way). Now, data from the very center of that picture are being presented at a different contrast to better highlight this jam-packed region. In visible-light pictures, it is all but impossible to see the heart of our galaxy, but infrared light penetrates the shroud of dust giving us this unprecedented view. In this Spitzer image, the myriad of stars crowding the center of our galaxy creates the blue haze that brightens towards the center of the image. The green features are from carbon-rich dust molecules, called polycyclic aromatic hydrocarbons, which are illuminated by the surrounding starlight as they swirl around the galaxy's core. The yellow-red patches are the thermal glow from warm dust. The polycyclic aromatic hydrocarbons and dust are associated with bustling hubs of young stars. These materials, mixed with gas, are required for making new stars. The brightest white feature at the center of the image is the central star cluster in our galaxy. At a distance of 26,000 light years away from Earth, it is so distant that, to Spitzer's view, most of the light from the thousands of individual stars is blurred into a single glowing blotch. Astronomers have determined that these stars are orbiting a massive black hole that lies at the very center of the galaxy. The region pictured here is immense, with a horizontal span of 2,400 light-years (5.3 degrees) and a vertical span of 1,360 light-years (3 degrees). Though most of the objects seen in this image are located near the galactic center, the features above and below the galactic plane tend to lie closer to Earth. The image is a three-color composite, showing infrared observations from two of Spitzer instruments. Blue represents 3.6-micron light and green shows 8-micron light, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer. The data is a combination of observations from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) project, and the Multiband Imaging Photometer for Spitzer Galactic survey (MIPSGAL).

The various spiral arm segments of the Sunflower galaxy, also known as Messier 63, show up vividly in this image taken in infrared light by NASA's Spitzer Space Telescope. Infrared light is sensitive to the dust lanes in spiral galaxies, which appear dark in visible-light images. Spitzer's view reveals complex structures that trace the galaxy's spiral arm pattern. Messier 63 is 37 million light years away -- not far from the well-known Whirlpool galaxy and the associated Messier 51 group of galaxies. The dust, glowing red in this image, can be traced all the way down into the galaxy's nucleus, forming a ring around the densest region of stars at its center. The dusty patches are where news stars are being born. The short diagonal line seen on the lower right side of the galaxy's disk is actually a much more distant galaxy, oriented with its edge facing toward us. Blue shows infrared light with wavelengths of 3.6 microns, green represents 4.5-micron light and red, 8.0-micron light. The contribution from starlight measured at 3.6 microns has been subtracted from the 8.0-micron image to enhance the visibility of the dust features.

The various spiral arm segments of the Sunflower galaxy, also known as Messier 63, show up vividly in this image taken in infrared light by NASA's Spitzer Space Telescope. Infrared light is sensitive to the dust lanes in spiral galaxies, which appear dark in visible-light images. Spitzer's view reveals complex structures that trace the galaxy's spiral arm pattern. Messier 63 is 37 million light years away -- not far from the well-known Whirlpool galaxy and the associated Messier 51 group of galaxies. The dust, glowing red in this image, can be traced all the way down into the galaxy's nucleus, forming a ring around the densest region of stars at its center. The dusty patches are where new stars are being born. The short diagonal line seen on the lower right side of the galaxy's disk is actually a much more distant galaxy, oriented with its edge facing toward us. Blue shows infrared light with wavelengths of 3.6 and 4.5 microns, green represents 8.0-micron light and red, 24-micron light.

This swirling landscape of stars is known as the North America nebula. In visible light, the region resembles North America, but in this new infrared view from NASA's Spitzer Space Telescope, the continent disappears. Where did the continent go? The reason you don't see it in Spitzer's view has to do, in part, with the fact that infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer's view. In addition, Spitzer's infrared detectors pick up the glow of dusty cocoons enveloping baby stars. Clusters of young stars (about one million years old) can be found throughout the image. Slightly older but still very young stars (about 3 to 5 million years) are also liberally scattered across the complex, with concentrations near the "head" region of the Pelican nebula, which is located to the right of the North America nebula (upper right portion of this picture). Some areas of this nebula are still very thick with dust and appear dark even in Spitzer's view. For example, the dark "river" in the lower left-center of the image -- in the Gulf of Mexico region -- are likely to be the youngest stars in the complex (less than a million years old). The Spitzer image contains data from both its infrared array camera and multiband imaging photometer. Light with a wavelength of 3.6 microns has been color-coded blue; 4.5-micron light is blue-green; 5.8-micron and 8.0-micron light are green; and 24-micron light is red.

This new view of the North America nebula combines both visible and infrared light observations, taken by the Digitized Sky Survey and NASA's Spitzer Space Telescope, respectively, into a single vivid picture. The nebula is named after its resemblance to the North America content in visible light, which in this image is represented in blue hues. Infrared light, displayed here in red and green, can penetrate deep into the dust, revealing multitudes of hidden stars and dusty clouds. Only the very densest dust clouds remain opaque, like the dark bands seen in the "Gulf of Mexico" area. Clusters of young stars (about one million years old) can be found throughout the image. Slightly older but still very young stars (about three to five million years) are also liberally scattered across the complex, with concentrations near the "head" region of the Pelican nebula, which is located to the right of the North America nebula (upper right, bluish portion of this picture). In this combined view, the visible part of the spectrum from the Digitized Sky Survey is represented in blues and blue-green hues. The Spitzer component contains data from the infrared array camera. Light with a wavelength of 3.6 microns has been color-coded green; 4.5-micron light is orange; 5.8-micron and 8.0-micron light are red.

This image layout compares visible (left) and infrared views of the North America nebula, taken by the Digitized Sky Survey and NASA's Spitzer Space Telescope, respectively. The nebula is named after its resemblance to the North America content in visible light. This visible view highlights the eastern seaboard and Gulf of Mexico regions. In infrared light, the continent disappears. The "Mexican Riviera" -- the west coast of Mexico -- seems to invert in texture and brightness, as does the "neck" region of the Pelican nebula, named for its resemblance to a pelican. This nebula can be seen to the right of the North America nebula in the visible image. The Gulf of Mexico transforms from a dark cloud into a "river" of hundreds of young stars. These pictures look different in part because infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer's view. In addition, Spitzer's infrared detectors pick up the glow of dusty cocoons enveloping baby stars. The Spitzer image contains data from both its infrared array camera and multiband imaging photometer. Light with a wavelength of 3.6 microns has been color-coded blue; 4.5-micron light is blue-green; 5.8-micron and 8.0-micron light are green; and 24-micron light is red.

This swirling landscape of stars is known as the North America nebula. In visible light, the region resembles North America, but in this new infrared view from NASA's Spitzer Space Telescope, the continent disappears. Where did the continent go? The reason you don't see it in Spitzer's view has to do, in part, with the fact that infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer's view. In addition, Spitzer's infrared detectors pick up the glow of dusty cocoons enveloping baby stars. Clusters of young stars (about one million years old) can be found throughout the image. Slightly older but still very young stars (about three to five million years) are also liberally scattered across the complex, with concentrations near the "head" region of the Pelican nebula, which is located to the right of the North America nebula (upper right portion of this image). Some areas of this nebula are still very thick with dust and appear dark even in Spitzer's view. For example, the dark "river" in the lower left-center of the image -- in the Gulf of Mexico region -- are likely to be the youngest stars in the complex (less than a million years old). This image contains data taken by Spitzer's infrared array camera at wavelengths of 3.6 (blue), 4.5 (green), 5.8 and 8.0 (red) microns.

This image layout reveals how the appearance of the North America nebula can change dramatically using different combinations of visible and infrared observations from the Digitized Sky Survey and NASA's Spitzer Space Telescope, respectively. In this progression, the visible-light view (upper left) shows a striking similarity to the North America continent. The image highlights the eastern seaboard and Gulf of Mexico regions. The red region to the right is known as the "Pelican nebula," after its resemblance in visible light to a pelican. The view at upper right includes both visible and infrared observations. The hot gas comprising the North America continent and the Pelican now takes on a vivid blue hue, while red colors display the infrared light. Inky black dust features start to glow in the infrared view. In the bottom two images, only infrared light from Spitzer is shown -- data from the infrared array camera is on the left, and data from both the infrared array camera and the multiband imaging photometer, which sees longer wavelengths, is on the right. These pictures look different in part because infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer's view. In addition, Spitzer's infrared detectors pick up the glow of dusty cocoons enveloping baby stars. Color is used to display different parts of the spectrum in each of these images. In the visible-light view (upper right) from the Digitized Sky Survey, colors are shown in their natural blue and red hues. The combined visible/infrared image (upper left) shows visible light as blue, and infrared light as green and red. The infrared array camera (lower left) represents light with a wavelength of 3.6 microns as blue, 4.5 microns as green, 5.8 microns as orange, and 8.0 microns as red. In the final image, incorporating the multiband imaging photometer data, light with a wavelength of 3.6 microns has been color coded blue; 4.5-micron light is blue-green; 5.8-micron and 8.0-micron light are green; and 24-micron light is red.

Stars at all stages of development, from dusty little tots to young adults, are on display in a new image from NASA's Spitzer Space Telescope. The cosmic community is called the North America nebula. In visible light, the region resembles the North America continent, with the most striking resemblance being the Gulf of Mexico. But in Spitzer's infrared view, the continent disappears. Instead, a swirling landscape of dust and young stars comes into view. This image focuses in on the Gulf of Mexico cluster of young stars. Several hundred young stars, seen here as the red dots, huddle together along their natal dark cloud -- what can be seen as the dark "river." In the main image, data from both the infrared array camera and multiband imaging photometer are included, showing infrared wavelengths of 3.6, 4.5, 5.8, 8, and 24 microns. In the inset, only data from the infrared array camera are shown, including wavelengths of 3.6, 4.5, 5.8, and 8 microns. The inset highlights jets from young stars, seen as green streaks near the stars.

Astronomers have discovered a massive cluster of young galaxies forming in the distant universe. The growing galactic metropolis, named COSMOS-AzTEC3, is the most distant known massive "proto-cluster" of galaxies, lying about 12.6 billion light-years away from Earth. Members of the developing cluster are shown here, circled in white, in this image taken by Japan's Subaru telescope atop Mauna Kea in Hawaii. The cluster was discovered by a suite of multi-wavelength telescopes, including NASA's Spitzer, Chandra and Hubble space observatories, Subaru and the W.M. Keck Observatory, also atop Mauna Kea in Hawaii. The other dots in this picture are stars or galaxies that are not members of the cluster -- most of the them are located closer to us than the cluster, but some are farther away. The two brightest spots are stars. Though they appear bright in this image, they are actually tens of thousands of times fainter than what we can see with our eyes.

This image layout illustrates how NASA's Spitzer Space Telescope was able to show that astandard candle" used to measure cosmological distances is shrinking -- a finding that affects precise measurements of the age, size and expansion rate of our universe. The image on the left, taken by Spitzer in infrared light, shows Delta Cephei, a type of standard candle used to measure the distances to galaxies that are relatively close to us. Cepheids like this one are the first rungs on the so-called cosmological distance ladder -- a tool needed to measure farther and farther distances. Spitzer showed that the star has a bow shock in front of it. This can be seen as the red arc shape to the left of the star, which is depicted in blue-green (the colors have been assigned to specific infrared wavelengths we can't see with our eyes). The presence of the bow shock told astronomers that Delta Cephei must have a wind that is forming the shock. This wind is made up of gas and dust blowing off the star. Before this finding, there was no direct proof that Cepheid stars could lose mass, or shrink. The finding is important because the loss of mass around a Cepheid can obscure the star's light, making it appear brighter in infrared observations, and dimmer in visible light, than it really is. This, in turn, affects calculations of how far away the star is. Even tiny inaccuracies in such distant measurements can cause the whole cosmological distance ladder to come unhinged. The diagram on the right illustrates how Delta Cephei's bow shock was formed. As the star speeds along through space, its wind hits interstellar gas and dust, causing it to pile up in the bow shock. A companion star to Delta Cephei, seen just below it, is lighting up the region, allowing Spitzer to better see the region. By examining the structure of the bow shock, astronomers were able to calculate how fast the star is losing mass. In this image, infrared light captured by the infrared array camera is blue and blue-green (3.6- and 4.5-micron light is blue and 8.0-micron light is blue-green). Infrared light captured by the multiband imaging photometer is colored green and red (24-micron light is green and 70-micron light is red).

Maffei 2 is the poster child for an infrared galaxy that is almost invisible to optical telescopes. Foreground dust clouds in the Milky Way block about 99.5% of its visible light, but this infrared image from NASAs Spitzer Space Telescope penetrates this dust to reveal the galaxy in all its glory. The astronomer Paolo Maffei first noted this as a mysterious smudge on a near infrared photographic plate in 1968. Four years later he identified the strange object to be a galaxy, now named after him. This discovery was made in the infancy of infrared astronomy and it would take many technological innovations in the following decades to allow astronomers to study obscured objects like this one in detail. Most other galaxies the size of Maffei 2 had been cataloged for over a century. Had it not been hidden behind dust lanes in our own galaxy it may well have been one of the entries in the famous 18th century catalog of bright deep sky objects compiled by Charles Messier. This Spitzer image clearly shows the unusual structure of Maffei 2. The strong central bar and asymmetric spiral arms help identify why the galaxy also harbors a starburst in its very core. Such dramatic bursts of star formation occur when massive amounts of dust and gas are driven into the center of a galaxy, often by gravitational interactions that create barred spiral structures in its disk.

This artist's concept shows the searing-hot gas planet WASP-12b (orange orb) and its star. NASA's Spitzer Space Telescope discovered that the planet has more carbon than oxygen, making it the first carbon-rich planet ever observed. Our planet Earth has relatively little amounts of carbon -- it is made largely of oxygen and silicon. Other gas planets in our solar system, for example Jupiter, are expected to have less carbon than oxygen, but this is not known. Unlike WASP-12b, these planets harbor water, the main oxygen carrier, deep in their atmospheres, where it is difficult to measure. Concentrated carbon can take the form of diamond, so astronomers say that carbon-rich gas planets could have abundant diamond in their interiors. WASP-12b is located roughly 1,200 light-years away in the constellation Auriga. It swings around its star every 1.1 days. Because the planet is so close to its star, the star's gravity stretches it slightly into an egg shape. The star's gravity also pulls material off the planet into a disk around the star (shown here in transparent, white hues).

This plot of data from NASA's Spitzer Space Telescope indicates the presence of molecules in the planet WASP-12b -- a super-hot gas giant that orbits tightly around its star. Spitzer measurements suggest this planet's atmosphere has carbon monoxide, excess methane, and not much water vapor. The results demonstrate that WASP-12b is the first known carbon-rich planet. Spitzer made these measurements as the planet circled behind the star, in an event called the secondary eclipse. The telescope collected the infrared light from the star and the planet, then just the star as the planet disappeared behind the star. This allowed astronomers to calculate the amount of infrared light coming solely from the planet. The observations were performed at four different wavelengths of infrared light. These data were then combined with previously reported measurements taken by the Canada-France-Hawaii Telescope atop Mauna Kea, Hawaii, at shorter infrared wavelengths to create this plot. The yellow dots show the data, along with the observational uncertainties. The blue curve is a model of the planet's light, or spectrum, showing the fingerprints of chemicals in the atmosphere. The blue dots represent the blue model curve averaged to cover the same wavelengths as the data, as shown by the gray lines at the bottom of the plot.