This artist's concept shows a dusty planet-forming disk in orbit around a whirling young star. NASA's Spitzer Space Telescope found evidence that disks like this one can slow their stars down, which prevents the stars from spinning themselves to death. A developing star is essentially a giant ball of gas that is collapsing onto itself. As it shrinks, it spins faster and faster, like a skater folding in his or her arms. As gravity continues to pull matter inward, the star spins so fast, it starts to flatten out. The same principle applies to the planet Saturn, whose spin has caused it to be slightly squashed or oblate. A forming star can theoretically whip around fast enough to overcome gravity and flatten itself into a state where it can no longer become a full-fledged star. But stars don't spin out of control, possibly because swirling disks of dust slow them down. Such disks can be found orbiting young stars, and are filled with dust that might ultimately stick together to form planets. How does a disk put the brakes on its star? It is thought to yank on the star's magnetic fields (green lines). When a star's magnetic fields pass through a disk, they are thought to get bogged down like a spoon in molasses. This locks a star's rotation to the slower-turning disk, so the star, while continuing to shrink, does not spin faster. Spitzer found evidence for star-slowing disks in a survey of nearly 500 forming stars in the Orion nebula. It observed that slowly spinning stars are five times more likely to host disks than rapidly spinning stars.

This artist concept illustrates jets of material shooting out from the neutron star in the binary system 4U 0614+091. Astronomers using the Spitzer Space Telescope found these remarkable jets, which are streaming into space at nearly the speed of light. Until this observation, astronomers thought that the ability to shoot such continuous jets into space was unique to black holes. The 4U 0614+091 system contains two stellar corpses, remnants of long-dead stars. The larger one (upper left) is the surviving core of a sun-like star, known as a "white dwarf." The smaller neutron star (lower right, at center of disk) is the dead core of a much more massive star that once exploded in a supernova. Even though the neutron star is tiny compared to the white dwarf it is incredibly dense and is actually about 14 times more massive! The white dwarf orbits the neutron star similar to the way the Earth orbits the sun. Like a cosmic vacuum cleaner, the neutron star's intense gravity picks up material leaving the white dwarf's atmosphere and collects it into a disk around itself. Known as an "accretion disk," the collected material orbits the neutron star similar to the way rings circle Saturn. The accretion disk is much denser than Saturn's rings, however, and under the influence of the neutron star's immense gravity the inner portions are heated to incredible temperatures. How the jets around the neutron star are created remains a mystery, but scientists note that accretion disks and intense gravitational fields are characteristics that both neutron stars in binary systems like this one and black holes share. They believe that these traits may be all that is needed to form and fuel the continuous jets of matter.

This plot tells astronomers that a pulsar, the remnant of a stellar explosion, is surrounded by a disk of its own ashes. The disk, revealed by the two data points at the far right from NASA's Spitzer Space Telescope, is the first ever found around a pulsar. Astronomers believe planets might rise up out of these stellar ashes. The data in this plot, or spectrum, were taken by ground-based telescopes and Spitzer. They show that light from around the pulsar can be divided into two categories: direct light from the pulsar, and light from the dusty disk swirling around the pulsar. This excess light was detected by Spitzer's infrared array camera. Dust gives off more infrared light than the pulsar because it's cooler. The pulsar, called 4U 0142+61, was once a massive star, until about 100,000 years ago, when it blew up in a supernova explosion and scattered dusty debris into space. Some of that debris was captured into what astronomers refer to as a "fallback disk," now circling the leftover stellar core, or pulsar. The disk resembles protoplanetary disks around young stars, out of which planets are thought to be born. The data have been corrected to remove the effects of light scattering from dust that lies between Earth and the pulsar. The ground-based data is from the Keck I telescope atop Mauna Kea, Hawaii.

This artist's concept depicts the pulsar planet system discovered by Aleksander Wolszczan in 1992. Wolszczan used the Arecibo radio telescope in Puerto Rico to find three planets - the first of any kind ever found outside our solar system - circling a pulsar called PSR B1257+12. Pulsars are rapidly rotating neutron stars, which are the collapsed cores of exploded massive stars. They spin and pulse with radiation, much like a lighthouse beacon. Here, the pulsar's twisted magnetic fields are highlighted by the blue glow. All three pulsar planets are shown in this picture; the farthest two from the pulsar (closest in this view) are about the size of Earth. Radiation from charged pulsar particles would probably rain down on the planets, causing their night skies to light up with auroras similar to our Northern Lights. One such aurora is illustrated on the planet at the bottom of the picture. Since this landmark discovery, more than 160 extrasolar planets have been observed around stars that are burning nuclear fuel. The planets spotted by Wolszczan are still the only ones around a dead star. They also might be part of a second generation of planets, the first having been destroyed when their star blew up. The Spitzer Space Telescope's discovery of a dusty disk around a pulsar might represent the beginnings of a similarly "reborn" planetary system.

This artist's concept depicts a type of dead star called a pulsar and the surrounding disk of rubble discovered by NASA's Spitzer Space Telescope. The pulsar, called 4U 0142+61, was once a massive star until about 100,000 years ago when it blew up in a supernova explosion and scattered dusty debris into space. Some of that debris was captured into what astronomers refer to as a "fallback disk," now circling the remaining stellar core, or pulsar. The disk resembles protoplanetary disks around young stars, out of which planets are thought to be born. Supernovas are a source of iron, nitrogen and other "heavy metals" in the universe. They spray these elements out into space, where they eventually come together in clouds that give rise to new stars and planets. The Spitzer finding demonstrates that supernovas might also contribute heavy metals to their own planets, a possibility that was first suggested when astronomers discovered planets circling a pulsar called PSR B1257+12 in 1992.

Monstrous disks like this one were discovered around two "hypergiant" stars by NASA's Spitzer Space Telescope. Astronomers believe these disks might contain the early "seeds" of planets, or possibly leftover debris from planets that already formed.The hypergiant stars, called R 66 and R 126, are located about 170,000 light-years away in our Milky Way's nearest neighbor galaxy, the Large Magellanic Cloud. The stars are about 100 times wider than the sun, or big enough to encompass an orbit equivalent to Earth's. The plump stars are heavy, at 30 and 70 times the mass of the sun, respectively. They are the most massive stars known to sport disks.The disks themselves are also bloated, with masses equal to several Jupiters. The disks begin at a distance approximately 120 times greater than that between Earth and the sun, or 120 astronomical units, and terminate at a distance of about 2,500 astronomical units.Hypergiant stars are the puffed-up, aging descendants of the most massive class of stars, called "O" stars. The stars are so massive that their cores ultimately collapse under their own weight, triggering incredible explosions called supernovae. If any planets circled near the stars during one of these blasts, they would most likely be destroyed.

This illustration compares the size of a gargantuan star and its surrounding dusty disk (top) to that of our solar system. Monstrous disks like this one were discovered around two "hypergiant" stars by NASA's Spitzer Space Telescope. Astronomers believe these disks might contain the early "seeds" of planets, or possibly leftover debris from planets that already formed. The hypergiant stars, called R 66 and R 126, are located about 170,000 light-years away in our Milky Way's nearest neighbor galaxy, the Large Magellanic Cloud. The stars are about 100 times wider than the sun, or big enough to encompass an orbit equivalent to Earth's. The plump stars are heavy, at 30 and 70 times the mass of the sun, respectively. They are the most massive stars known to sport disks. The disks themselves are also bloated, with masses equal to several Jupiters. The disks begin at a distance approximately 120 times greater than that between Earth and the sun, or 120 astronomical units, and terminate at a distance of about 2,500 astronomical units. Hypergiant stars are the puffed-up, aging descendants of the most massive class of stars, called "O" stars. The stars are so massive that their cores ultimately collapse under their own weight, triggering incredible explosions called supernovae. If any planets circled near the stars during one of these blasts, they would most likely be destroyed. The orbital distances in this picture are plotted on a logarithmic scale. This means that a given distance shown here represents proportionally larger actual distances as you move to the right. The sun and planets in our solar system have been scaled up in size for better viewing.

This illustration compares the size of a gargantuan star and its surrounding dusty disk (top) to that of our solar system. Monstrous disks like this one were discovered around two "hypergiant" stars by NASA's Spitzer Space Telescope. Astronomers believe these disks might contain the early "seeds" of planets, or possibly leftover debris from planets that already formed. The hypergiant stars, called R 66 and R 126, are located about 170,000 light-years away in our Milky Way's nearest neighbor galaxy, the Large Magellanic Cloud. The stars are about 100 times wider than the sun, or big enough to encompass an orbit equivalent to Earth's. The plump stars are heavy, at 30 and 70 times the mass of the sun, respectively. They are the most massive stars known to sport disks. The disks themselves are also bloated, with masses equal to several Jupiters. The disks begin at a distance approximately 120 times greater than that between Earth and the sun, or 120 astronomical units, and terminate at a distance of about 2,500 astronomical units. Hypergiant stars are the puffed-up, aging descendants of the most massive class of stars, called "O" stars. The stars are so massive that their cores ultimately collapse under their own weight, triggering incredible explosions called supernovae. If any planets circled near the stars during one of these blasts, they would most likely be destroyed. The orbital distances in this picture are plotted on a logarithmic scale. This means that a given distance shown here represents proportionally larger actual distances as you move to the right. The sun and planets in our solar system have been scaled up in size for better viewing.

This graph of data from NASA's Spitzer Space Telescope shows the composition of a monstrous disk of what may be planet-forming dust circling the colossal "hypergiant" star called R 66. The disk contains complex organic molecules called polycyclic aromatic hydrocarbons as well as silicate dust grains. Polycyclic aromatic hydrocarbons can be found on Earth, in dirty barbeques and automobile exhaust pipes, among other places. They are thought to be necessary for primitive life to evolve. Silicates are essentially sand, and, in this case, were found in both their crystalline and non-crystalline, or amorphous, forms. The data were taken by Spitzer's infrared spectrometer, an instrument that spreads light apart into its basic parts like a prism turning sunlight into a rainbow. In this graph, or spectrum, light from the dust surrounding hypergiant R 66 is plotted according to its component wavelengths (white line). Astronomers determined the contents of this dust by creating a model (gray line) that best fits the observations. The model is the sum total of contributions from various types of dust grains (colored lines). In addition to R 66, Spitzer made similar observations of a huge disk around the hypergiant star R 126, only this star's disk did not possess crystalline silicate grains. Both disks might represent either an early or late evolutionary phase of the planet-building process. In either scenario, the possible solar systems would be supersized, with host stars that are 30 and 70 times the mass of our sun, respectively.

This graph of data, or spectrum, from NASA's Spitzer Space Telescope indicates that a dead star, or white dwarf, called G29-38, is shrouded by a cloud of dust. The data also demonstrate that this dust contains some of the same types of minerals found in comet Hale-Bopp. The findings tell a possible tale of solar system survival. Though the dust seen by Spitzer is likely from a comet that recently perished, its presence suggests that an icy distant ring of comets may still orbit the dead star. These data were collected by Spitzer's infrared spectrometer, an instrument that cracks light open like a geode, revealing its coveted components. In this spectrum, light from the white dwarf is on the left, at ultraviolet and visible wavelengths. The spectrum on the right, at infrared wavelengths longer than about 2 microns, shows much more light than can be explained by a white dwarf alone. The bump seen around a wavelength of 10 microns offers a clue to the source of this excess infrared light. It signifies the presence of silicate minerals, which are found in our own solar system on Earth, in sandy beaches, and in comets and asteroids. These silicate grains appear to be very small like those in comets, so astronomers favor the theory that a comet recently broke apart around the dead star.

This is an illustration of one of the most massive star clusters within our Milky Way Galaxy. The cluster is ablaze with the glow of 14 rare red supergiant stars. Interspersed among the supergiants are young blue stars. The cluster contains an estimated 20,000 stars and is 20 times more massive than typical clusters in our galaxy. The cluster is located in the direction of the Galaxy's center. Its visible light is obscured by interstellar dust, but infrared telescopes easily detect the cluster's glow. If it could be seen in visible light, it would resemble this illustration. In this perspective we are looking back across the Milky Way, in the direction of the Sun, 18,900 light-years away. The cluster is only 8 to 10 million years old, young enough for astronomers to see most of the red supergiants before they explode as supernovae. One supernova remnant is located in the cluster at far left. In the background at the 12:00 position is a distant region of stars called W 42.

The sky is a jewelry box full of sparkling stars in these infrared images. The crown jewels are 14 massive stars on the verge of exploding as supernovae. These hefty stars reside in one of the most massive star clusters in the Milky Way Galaxy. The bluish cluster is inside the white box in the large image, which shows the star-studded region around it. A close-up of the cluster can be seen in the inset photo. These large stars are a tip-off to the mass of the young cluster. Astronomers estimate that the cluster is at least 20,000 times as massive as the Sun. Each red supergiant is about 20 times the Sun's mass. The larger color-composite image was taken by the Spitzer Space Telescope for the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) Legacy project. The survey penetrates obscuring dust along the thick disk of our galaxy to reveal never-before-seen stars and star clusters. The false colors in the image correspond to infrared-light emission. The stars in the large color-composite image all appear blue because they emit most of their infrared light at shorter wavelengths. The inset image, a false-color composite, was captured by the Two Micron All Sky Survey (2MASS). Astronomers identified the cluster as a potential behemoth after spotting it in the 2MASS catalogue. They then used the Infrared Multi-object Spectrograph at the Kitt Peak National Observatory in Arizona to analyze the cluster's colors. From that analysis, they discovered the red supergiants. They confirmed the red supergiants' pedigree by studying the colors of other red supergiants in data taken by the Spitzer Space Telescope. The cluster lies 18,900 light-years away in the direction of the constellation Scutum. It is the first in a survey of 130 potentially massive star clusters in the Milky Way that astronomers will study over the next five years using a variety of telescopes, including the Spitzer and Hubble space telescopes. The Spitzer image was taken April 4, 2004; the 2MASS image on July 4, 1999. The science team that studied the star cluster consists of Don Figer, Space Telescope Science Institute/Rochester Institute of Techology; John MacKenty, Massimo Robberto, and Kester Smith, Space Telescope Science Institute; Francisco Najarro, Instituto de Estructura de la Materia in Madrid, Spain: Rolf Kudritzki, University of Hawaii in Honolulu; and Artemio Herrero, Universidad de La Laguna in Tenerife, Spain.

The sky is a jewelry box full of sparkling stars in these infrared images. The crown jewels are 14 massive stars on the verge of exploding as supernovae. These hefty stars reside in one of the most massive star clusters in the Milky Way Galaxy. The bluish cluster is inside the white box in the large image, which shows the star-studded region around it. A close-up of the cluster can be seen in the inset photo. These large stars are a tip-off to the mass of the young cluster. Astronomers estimate that the cluster is at least 20,000 times as massive as the Sun. Each red supergiant is about 20 times the Sun's mass. The image, a false-color composite, was captured by the Two Micron All Sky Survey (2MASS). Astronomers identified the cluster as a potential behemoth after spotting it in the 2MASS catalogue. They then used the Infrared Multi-object Spectrograph at the Kitt Peak National Observatory in Arizona to analyze the cluster's colors. From that analysis, they discovered the red supergiants. They confirmed the red supergiants' pedigree by studying the colors of other red supergiants in data taken by the Spitzer Space Telescope. The cluster lies 18,900 light-years away in the direction of the constellation Scutum. It is the first in a survey of 130 potentially massive star clusters in the Milky Way that astronomers will study over the next five years using a variety of telescopes, including the Spitzer and Hubble space telescopes. The 2MASS image was taken on July 4, 1999. The science team that studied the star cluster consists of Don Figer, Space Telescope Science Institute/Rochester Institute of Techology; John MacKenty, Massimo Robberto, and Kester Smith, Space Telescope Science Institute; Francisco Najarro, Instituto de Estructura de la Materia in Madrid, Spain: Rolf Kudritzki, University of Hawaii in Honolulu; and Artemio Herrero, Universidad de La Laguna in Tenerife, Spain.

The sky is a jewelry box full of sparkling stars in these infrared images. The crown jewels are 14 massive stars on the verge of exploding as supernovae. These hefty stars reside in one of the most massive star clusters in the Milky Way Galaxy. The bluish cluster is inside the white box in the large image, which shows the star-studded region around it. A close-up of the cluster can be seen in the inset photo. These large stars are a tip-off to the mass of the young cluster. Astronomers estimate that the cluster is at least 20,000 times as massive as the Sun. Each red supergiant is about 20 times the Sun's mass. The larger color-composite image was taken by the Spitzer Space Telescope for the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) Legacy project. The survey penetrates obscuring dust along the thick disk of our galaxy to reveal never-before-seen stars and star clusters.The false colors in the image correspond to infrared-light emission. The stars in the large color-composite image all appear blue because they emit most of their infrared light at shorter wavelengths. The cluster lies 18,900 light-years away in the direction of the constellation Scutum. It is the first in a survey of 130 potentially massive star clusters in the Milky Way that astronomers will study over the next five years using a variety of telescopes, including the Spitzer and Hubble space telescopes. The Spitzer image was taken April 4, 2004. The science team that studied the star cluster consists of Don Figer, Space Telescope Science Institute/Rochester Institute of Techology; John MacKenty, Massimo Robberto, and Kester Smith, Space Telescope Science Institute; Francisco Najarro, Instituto de Estructura de la Materia in Madrid, Spain: Rolf Kudritzki, University of Hawaii in Honolulu; and Artemio Herrero, Universidad de La Laguna in Tenerife, Spain. The science team that studied the star cluster consists of Don Figer, Space Telescope Science Institute/Rochester Institute of Techology; John MacKenty, Massimo Robberto, and Kester Smith, Space Telescope Science Institute; Francisco Najarro, Instituto de Estructura de la Materia in Madrid, Spain: Rolf Kudritzki, University of Hawaii in Honolulu; and Artemio Herrero, Universidad de La Laguna in Tenerife, Spain.

Newborn stars, hidden behind thick dust, are revealed in this image of a section of the Christmas Tree Cluster from NASA's Spitzer Space Telescope, created in joint effort between Spitzer's Infrared Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) instruments. The newly revealed infant stars appear as pink and red specks toward the center of the combined IRAC-MIPS image. The stars appear to have formed in regularly spaced intervals along linear structures in a configuration that resembles the spokes of a wheel or the pattern of a snowflake. Hence, astronomers have nicknamed this the "Snowflake Cluster." Star-forming clouds like this one are dynamic and evolving structures. Since the stars trace the straight line pattern of spokes of a wheel, scientists believe that these are newborn stars, or "protostars." At a mere 100,000 years old, these infant structures have yet to "crawl" away from their location of birth. Over time, the natural drifting motions of each star will break this order, and the snowflake design will be no more. While most of the visible-light stars that give the Christmas Tree Cluster its name and triangular shape do not shine brightly in Spitzer's infrared eyes, all of the stars forming from this dusty cloud are considered part of the cluster.Like a dusty cosmic finger pointing up to the newborn clusters, Spitzer also illuminates the optically dark and dense Cone Nebula, the tip of which can be seen towards the bottom left corner of the image. The combined IRAC-MIPS image shows the presence of organic molecules mixed with dust as wisps of green, which have been illuminated by nearby star formation. The larger yellowish dots neighboring the baby red stars in the Snowflake Cluster are massive stellar infants forming from the same cloud. The blue dots sprinkled across the image represent older Milky Way stars at various distances along this line of sight. The image is a five-channel, composite, showing emission from wavelengths of 3.6 and 4.5 microns (blue), 5.8 microns (cyan), 8 microns (green), and 24 microns (red).

Newborn stars, hidden behind thick dust, are revealed in this image of a section of the Christmas Tree Cluster from NASA's Spitzer Space Telescope with the Multiband Imaging Photometer (MIPS) instrument. The stars appear to have formed in regularly spaced intervals along linear structures in a configuration that resembles the spokes of a wheel or the pattern of a snowflake. Hence, astronomers have nicknamed this the "Snowflake Cluster." Star-forming clouds like this one are dynamic and evolving structures. Since the stars trace the straight line pattern of spokes of a wheel, scientists believe that these are newborn stars, or "protostars." At a mere 100,000 years old, these infant structures have yet to "crawl" away from their location of birth. Over time, the natural drifting motions of each star will break this order, and the snowflake design will be no more. While most of the visible-light stars that give the Christmas Tree Cluster its name and triangular shape do not shine brightly in Spitzer's infrared eyes, all of the stars forming from this dusty cloud are considered part of the cluster. Like a dusty cosmic finger pointing up to the newborn clusters, Spitzer also illuminates the optically dark and dense Cone Nebula, the tip of which can be seen towards the bottom left corner of the image.MIPS' far-infrared eyes the colder dust of the nebula and unwraps the youngest stellar babies from their dusty covering. This is an infrared image showing emission at 24 microns (red).

Newborn stars, hidden behind thick dust, are revealed in this image of a section of the Christmas Tree Cluster from NASA's Spitzer Space Telescope, as seen by Spitzer's Infrared Array Camera (IRAC). The stars appear to have formed in regularly spaced intervals along linear structures in a configuration that resembles the spokes of a wheel or the pattern of a snowflake. Hence, astronomers have nicknamed this the "Snowflake Cluster." Star-forming clouds like this one are dynamic and evolving structures. Since the stars trace the straight line pattern of spokes of a wheel, scientists believe that these are newborn stars, or "protostars." At a mere 100,000 years old, these infant structures have yet to "crawl" away from their location of birth. Over time, the natural drifting motions of each star will break this order, and the snowflake design will be no more. While most of the visible-light stars that give the Christmas Tree Cluster its name and triangular shape do not shine brightly in Spitzer's infrared eyes, all of the stars forming from this dusty cloud are considered part of the cluster.Like a dusty cosmic finger pointing up to the newborn clusters, Spitzer also illuminates the optically dark and dense Cone Nebula, the tip of which can be seen towards the bottom left corner of the image. IRAC's near and mid-infrared eyes show that the nebula is still actively forming stars. The wisps of red are organic molecules mixed with dust, which has been illuminated by nearby star formation. The IRAC picture is a four-channel, composite, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red).

Newborn stars, hidden behind thick dust, are revealed in this image of a section of the Christmas Tree Cluster from NASA's Spitzer Space Telescope, created in joint effort between Spitzer's Infrared Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) instruments. The newly revealed infant stars appear as pink and red specks toward the center of the combined IRAC-MIPS image (left panel). The stars appear to have formed in regularly spaced intervals along linear structures in a configuration that resembles the spokes of a wheel or the pattern of a snowflake. Hence, astronomers have nicknamed this the "Snowflake Cluster." Star-forming clouds like this one are dynamic and evolving structures. Since the stars trace the straight line pattern of spokes of a wheel, scientists believe that these are newborn stars, or "protostars." At a mere 100,000 years old, these infant structures have yet to "crawl" away from their location of birth. Over time, the natural drifting motions of each star will break this order, and the snowflake design will be no more. While most of the visible-light stars that give the Christmas Tree Cluster its name and triangular shape do not shine brightly in Spitzer's infrared eyes, all of the stars forming from this dusty cloud are considered part of the cluster.Like a dusty cosmic finger pointing up to the newborn clusters, Spitzer also illuminates the optically dark and dense Cone Nebula, the tip of which can be seen towards the bottom left corner of each image. The combined IRAC-MIPS image shows the presence of organic molecules mixed with dust as wisps of green, which have been illuminated by nearby star formation. The larger yellowish dots neighboring the baby red stars in the Snowflake Cluster are massive stellar infants forming from the same cloud. The blue dots sprinkled across the image represent older Milky Way stars at various distances along this line of sight. The image is a five-channel, composite, showing emission from wavelengths of 3.6 and 4.5 microns (blue), 5.8 microns (cyan), 8 microns (green), and 24 microns (red). IRAC's near and mid-infrared eyes (top right) show that the nebula is still actively forming stars. The wisps of red (represented as green in the IRAC-MIPS image) are organic molecules mixed with dust, which has been illuminated by nearby star formation. The IRAC picture is a four-channel, composite, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red). MIPS' far-infrared eyes (bottom right) the colder dust of the nebula and unwraps the youngest stellar babies from their dusty covering. This is a image showing emission at 24 microns (red).

This artist's concept illustrates a solar system that is a much younger version of our own. Dusty disks, like the one shown here circling the star, are thought to be the breeding grounds of planets, including rocky ones like Earth. Astronomers using NASA's Spitzer Space Telescope spotted some of the raw ingredients for DNA and protein in one such disk belonging to a star called IRS 46. The ingredients, gaseous precursors to DNA and protein called acetylene and hydrogen cyanide, were detected in the star's inner disk, the region where scientists believe Earth-like planets would be most likely to form.

This graph, or spectrum, from NASA's Spitzer Space Telescope tells astronomers that some of the most basic ingredients of DNA and protein are concentrated in a dusty planet-forming disk circling a young sun-like star called IRS 46. These data also indicate that the ingredients -- molecular gases called acetylene and hydrogen cyanide -- are located in the star's terrestrial planet zone, the region where scientists believe Earth-like planets would be most likely to form. The data were acquired by Spitzer's infrared spectrograph, which splits light from the star's disk into distinct features characteristic of a particular chemical. The features, seen here as bumps and squiggles, are like bar codes used in supermarkets to identify different products. In this case, the products are the two DNA and protein precursors, acetylene and hydrogen cyanide, as well as carbon dioxide gas. All three gases are termed "organic" because they contain the element carbon. The shapes of the features in this spectrum helped pinpoint the location of the gases in the star's disk. A feature's shape reflects the temperature of the gas. By comparison with model spectra, astronomers were able to deduce that the gases are present in regions where the temperature ranges from approximately the boiling point of water on Earth (212 degrees Fahrenheit), to nearly a thousand degrees Fahrenheit. Such hot temperatures place the gases in the star's terrestrial planet zone, which is sometimes referred to as the "Goldilocks" zone because it is just right for Earths. Acetylene and hydrogen cyanide are some of life's most basic starting materials. If you mix them together in a test tube with water, and give them some kind of surface on which to be concentrated and react, you'll get a slew of organic compounds, including many of the 20 essential amino acids and one of the four chemical units, called bases, that make up DNA.

This artist's concept depicts a distant hypothetical solar system, similar to the one recently discovered with the Spitzer Space Telescope. In this artist's rendering, a narrow asteroid belt filled with rocks and dusty debris, orbits a star similar to our own Sun when it was approximately 30 million years old (about the time Earth formed). Within the belt a hypothetical planet also circles the star. Using the Spitzer's heat-seeking infrared eyes, astronomers have recently discovered a similar debris belt surrounding a distant star. While no planets were detected directly by Spitzer, the narrow size of the newly discovered belt hints at the possibility of a planetary system. Just as small moons shepherd ice grains orbiting Saturn into discrete rings, and just as Jupiter tends the outer edge of our solar system's asteroid belt, astronomers suspect one or more planets may be confining the debris within this narrow ring around the star.

How can you tell if a star is orbited by a narrow disk, or belt, of dust when the belt is too small to image directly? Astronomers can tell by measuring the temperature of the dust using infrared telescopes like the Spitzer Space Telescope. Just as the color of the burners on an electric stovetop turn from "red" to "white" hot as they get hotter, the temperature of an object can be determined from its color. Astronomers quantify the color of an object by measuring its spectrum, which is the intensity (brightness) of an object at several different wavelengths of light. The infrared wavelengths measured by Spitzer range from 3 to 160 microns.The top illustration represents the spectrum of a star with no disk. The distribution of light at any given wavelength follows a specific and well-known curve, determined by the laws of physics and the temperature of the star. Due to the star's high temperature, most of the light is produced at shorter wavelengths (the left side of the diagram),In the second diagram, we see the spectrum of a star with a continuous disk of dust around it. The dust is heated by the star, just as our earth is heated by the sun. However, the material is cooler than the surface of the star, so it emits most of its light at longer (infrared) wavelengths. In this object, there is an excess of infrared emission, which cannot be coming from the star itself. The disk is revealed. The smooth slope of the curve indicates that there is dust at many different temperatures, which can only happen if dust orbits the star in a continuous disk.In the third diagram we again see the spectrum of a star with a dusty disk around it, but in this case, the dust emits at a single temperature, which means that the dust is confined to a belt surrounding the star. The wavelength of the "bump" in the spectrum allows astronomers to measure this temperature, and from that determine how far from the star the belt must lay.

Using an automated computer method to sift through data collected by NASA's Spitzer Space Telescope, astronomers on the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) team found a new star cluster (inset) in our Milky Way galaxy, in the northern constellation Aquila (main image). The new cluster is seen in the center of the red nebula, or star-forming cloud, as the grouping of small blue, yellow, and green stars. The wisps of red are organic molecules within the dust which have been illuminated by nearby star formation. Green indicates the presence of hot hydrogen gas. Blue predominantly reveals older stars. The bright white arc located to the lower left side of the central star cluster shows the area where a massive star is forming. For years, dense obscuring clouds of dust have blocked the central cluster from optical view. The high density of the stars triggered the GLIMPSE team's automatic cluster-finding computer program to the presence of this cluster. There are still some dust clouds even in the heart of this cluster, as seen in the inset, indicating, that stars are probably still being formed today. With time, these clouds will disappear as more stars form. The infrared image was captured with the Spitzer's infrared array camera (IRAC). The picture is a 4-channel color composite, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red).

Using an automated computer method to sift through data collected by NASA's Spitzer Space Telescope, astronomers on the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) team found a new star cluster in our Milky Way galaxy, in the northern constellation Aquila. The new cluster is seen in the center of the red nebula, or star-forming cloud, as the grouping of small blue, yellow, and green stars. The wisps of red are organic molecules within the dust which have been illuminated by nearby star formation. Green indicates the presence of hot hydrogen gas. Blue predominantly reveals older stars. The bright white arc located to the lower left side of the central star cluster shows the area where a massive star is forming. For years, dense obscuring clouds of dust have blocked the central cluster from optical view. The high density of the stars triggered the GLIMPSE team's automatic cluster-finding computer program to the presence of this cluster. There are still some dust clouds even in the heart of this cluster, as seen in the inset, indicating, that stars are probably still being formed today. With time, these clouds will disappear as more stars form. The infrared image was captured with the Spitzer's infrared array camera (IRAC). The picture is a 4-channel composite, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red). The new cluster is seen in the center of the red nebula, or star-forming cloud, as the grouping of small blue, yellow, and green stars. The wisps of red are organic molecules within the dust which have been illuminated by nearby star formation. Green indicates the presence of hot hydrogen gas. Blue predominantly reveals older stars. The bright white arc located to the lower left side of the central star cluster shows the area where a massive star is forming. For years, dense obscuring clouds of dust have blocked the central cluster from optical view. The high density of the stars triggered the GLIMPSE team's automatic cluster-finding computer program to the presence of this cluster. There are still some dust clouds even in the heart of this cluster, as seen in the inset, indicating, that stars are probably still being formed today. With time, these clouds will disappear as more stars form.The infrared image was captured with the Spitzer's infrared array camera (IRAC). The picture is a 4-channel composite, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red).

Using an automated computer method to sift through data collected by NASA's Spitzer Space Telescope, astronomers on the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) team found a new star cluster in our Milky Way galaxy, in the northern constellation Aquila. The new cluster is found as the grouping of small blue, yellow, and green stars. The wisps of red are organic molecules within the dust which have been illuminated by nearby star formation. Green indicates the presence of hot hydrogen gas. Blue predominantly reveals older stars. The bright white arc located to the lower left side of the central star cluster shows the area where a massive star is forming. For years, dense obscuring clouds of dust have blocked the central cluster from optical view. The high density of the stars triggered the GLIMPSE team's automatic cluster-finding computer program to the presence of this cluster. There are still some dust clouds even in the heart of this cluster, as seen in the inset, indicating, that stars are probably still being formed today. With time, these clouds will disappear as more stars form. The infrared image was captured with the Spitzer's infrared array camera (IRAC). The picture is a 4-channel composite, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red).

This artist's conception compares a hypothetical solar system centered around a tiny "sun" (top) to a known solar system centered around a star, called 55 Cancri, which is about the same size as our sun. NASA's Spitzer Space Telescope, in combination with other ground-based and orbiting telescopes, discovered the beginnings of such a miniature solar system 500 light-years away in the Chamaeleon constellation. The tiny system consists of an unusually small "failed" star, or brown dwarf, called Cha 110913-773444, and a surrounding disk of gas and dust that might one day form planets. At a mass of only eight times that of Jupiter, the brown dwarf is actually smaller than several known extrasolar planets. The largest planet in the 55 Cancri system is about four Jupiter masses. Astronomers speculate that the disk around Cha 110913-773444 might have enough mass to make a small gas giant and a few Earth-sized rocky planets, as depicted here around the little brown dwarf.

This artist's concept shows microscopic crystals in the dusty disk surrounding a brown dwarf, or "failed star." The crystals, made up of a green mineral found on Earth called olivine, are thought to help seed the formation of planets. NASA's Spitzer Space Telescope detected the tiny crystals circling around five brown dwarfs, the cooler and smaller cousins of stars. Though crystallized minerals have been seen in space before -- in comets and around other stars -- the discovery represents the first time the little gem-like particles have been spotted around confirmed brown dwarfs. Astronomers believe planets form out of disks of dust that circle young brown dwarfs and stars. Over time, the various minerals making up the disks crystallize and begin to clump together. Eventually, the clumps collide and stick, building up mass like snowmen until planets are born.

Astronomers using NASA's Spitzer Space Telescope have gathered the most detailed data yet on a gap in a protoplanetary, or planet-forming, disk surrounding a young star. This artist's concept illustrates one interpretation of the data, which attributes the disk gap to planet formation. At the center lies a young star that is pulling in material from an inner disk of dust and gas. The gap between this inner disk and the thick outer disk is believed to be occupied by developing gas giant planets. The putative planets prevent the outer disk material from naturally falling in toward the star, thereby creating the gap. The inner disk is roughly the size of our inner solar system, or the distance between the Sun and Jupiter. The gap would span orbits equivalent to those of Jupiter and Saturn. The Saturn-like rings around the planets hint that they are very young and still surrounded by debris left over from their own formation. (Note: the planets in this illustration are exaggerated in size.) At the edges of the solar system, the thick disk is expected to coalesce into asteroids, comets and possibly more planets. The bipolar flow, or dim jets of material, shooting out of the star's north and south poles, is a characteristic typical of young stars that are not yet fully formed.

Astronomers were surprised to discover a 25-million-year-old protoplanetary disk around a pair of red dwarf stars 350 light-years away. Gravitational stirring by the binary star system (shown in this artist's conception) may have prevented planet formation.

This artist's concept show a massive asteroid belt in orbit around a star the same age and size as our Sun. Evidence for this possible belt was discovered by NASA's Spitzer Space Telescope when it spotted warm dust around the star, presumably from asteroids smashing together.The view is from outside the belt, where planets like the one shown in the foreground, might possibly reside. A collision between two asteroids is depicted to the right. Collisions like this replenish the dust in the asteroid belt, making it detectable to Spitzer.The alien belt circles a faint, nearby star called HD 69830 located 41 light-years away in the constellation Puppis. Compared to our own solar system's asteroid belt, this one is larger and closer to its star -- it is 25 times as massive, and lies just inside an orbit equivalent to that of Venus. Our asteroid belt circles between the orbits of Mars and Jupiter.Because Jupiter acts as an outer wall to our asteroid belt, shepherding its debris into a series of bands, it is possible that an unseen planet is likewise marshalling this belt's rubble. Previous observations using the radial velocity technique did not locate any large gas giant planets, indicating that any planets present in this system would have to be the size of Saturn or smaller.Asteroids are chunks of rock from "failed" planets, which never managed to coalesce into full-sized planets. Asteroid belts can be thought of as construction sites that accompany the building of rocky planets.