Can you see the dark spot moving in the bottom left corner of the screen? It’s a brown dwarf nicknamed “The Accident,” which was discovered by citizen scientist Dan Caselden. It had slipped past typical searches because it doesn’t look like any other known brown dwarfs.

This illustration depicts the fastest spinning brown dwarf found to date. Astronomers using NASA's Spitzer Space Telescope found 2MASS J0348-6022 rotates on its axis every 1.08 hours, about ten times faster than Jupiter and Saturn. The faster a brown dwarf spins, the narrower the different-colored atmospheric bands on it likely become, as shown in this illustration. Some brown dwarfs glow in visible light, but they are typically brightest in infrared wavelengths, which are longer than what human eyes can see. Brown dwarfs are more massive than most planets but not quite as massive as stars. Generally speaking, they have between 13 and 80 times the mass of Jupiter. A brown dwarf becomes a star if its core pressure gets high enough to start nuclear fusion.

This graph presents measured properties of the seven TRAPPIST-1 exoplanets (labeled b through h), showing how they stack up with one another as well as with Earth and the other inner rocky worlds in our own solar system. The relative sizes of the planets are indicated by the circles. All of the known TRAPPIST-1 planets are larger than Mars, with five of them within 15% of the diameter of Earth. The vertical axis shows the uncompressed densities of the planets. Density, calculated from a planets mass and volume, is the first important step in understanding its composition. Uncompressed density takes into account that the larger a planet is, the more its own gravity will pack the planets material together and increase its density. Uncompressed density, therefore, usually provides a better means of comparing the composition of planets. The plot shows that the uncompressed densities of the TRAPPIST-1 planets are similar to one another, suggesting they may have all have a similar composition. The four rocky planets in our own solar system show more variation in density compared to the seven TRAPPIST-1 planets. Mercury, for example, contains a much higher percentage of iron than the other three rocky planets and thus has a much higher uncompressed density. The horizontal axis shows the level of illumination that each planet receives from its host star. The TRAPPIST-1 star is a mere 9% the mass of our Sun, and its temperature is much cooler. But because the TRAPPIST-1 planets orbit so closely to their star, they receive comparable levels of light and heat to Earth and its neighboring planets. The corresponding habitable zones regions where an Earth-like planet could potentially support liquid water on its surface of the two planetary systems are indicated near the top of the plot. The the two zones do not line up exactly because the cooler TRAPPIST-1 star emitting more of its light in the form of infrared radiation that is more efficiently absorbed by an Earth-like atmosphere. Since it takes less illumination to reach the same temperatures, the habitable zone shifts farther away from the star. The masses and densities of the TRAPPIST-1 planets were determined by measurements of slight variations in the timings of their orbits using extensive observations made by NASAs Spitzer and Kepler space telescopes, in combination with data from Hubble and a number of ground-based telescopes. The latest analysis, which includes Spitzers complete record of over 1,000 hours of TRAPPIST-1 observations, has reduced the uncertainties of the mass measurements to a mere 3-6%. These are among the most accurate measurements of planetary masses anywhere outside of our solar system.

Detailed measurements of the physical properties of the seven rocky TRAPPIST-1 planets and the four terrestrial planets in our solar system help scientists find similarities and differences between the two planet families.

Measuring the mass and diameter of a planet reveals its density, which can give scientists clues about its composition. Scientists now know the density of the seven TRAPPIST-1 planets with a higher precision than any other planets in the universe, other than those in our own solar system

This illustration shows three possible interiors of the seven rocky exoplanets in the TRAPPIST-1 system, based on precision measurements of the planet densities. Overall the TRAPPIST-1 worlds have remarkably similar densities, which suggests they may share the same ratio of common planet-forming elements. The planet densities are slightly lower than those of Earth or Venus, which could mean they contain fractionally less iron (a highly dense material) or more low-density materials, such as water or oxygen. In the first model (left), the interior of the planet is composed of rock mixed with iron bound to oxygen. There is no solid iron core, which is the case with Earth and the other rocky planets in our own solar system. The second model shows an overall composition similar to Earths, in which the densest materials have settled to the center of the planet, forming an iron-rich core proportionally smaller than Earths core. A variation is shown in the third panel, where a larger, denser core could be balanced by an extensive low-density ocean on the planet's surface. However, this scenario can be applied only to the outer four planets in the TRAPPIST-1 system. On the inner three planets, any oceans would vaporize due to the higher temperatures near their star, and a different composition model is required. Since all seven planets have remarkably similar densities, it is more likely that all the planets share a similar bulk composition, making this fourth scenario unlikely but not impossible. The high-precision mass and diameter measurements of the exoplanets in the TRAPPIST-1 system have allowed astronomers to calculate the overall densities of these worlds with an unprecedented degree of accuracy in exoplanet research. Density measurements are a critical first step in determining the composition and structure of exoplanets, but they must be interpreted through the lens of scientific models of planetary structure.

Two supermassive black holes are locked in an orbital dance at the core of the distant galaxy OJ 287. This diagram shows their sizes relative to the solar system. The larger one, with about 18 billion times the mass of our sun (right), would encompass all the planets in the solar system with room to spare. The smaller one is about 150 million times the mass of our sun (left), which would be large enough to swallow up everything out to the asteroid belt, just inside the orbit of Jupiter.

This artwork shows two massive black holes in the OJ 287 galaxy. The smaller black hole orbits the larger one, which remains stationary and is surrounded by a disk of gas. When the smaller black hole crashes through the disk, it produces a flare brighter than 1 trillion stars. But the smaller black hole's orbit is elongated and moving relative to the disk, causing the flares to occur irregularly.

For the first time, scientists have directly measured wind speed on a brown dwarf, pictured here in an illustration. Brown dwarfs are objects larger than Jupiter (the largest planet in our solar system) but not quite massive enough to become stars. To achieve the finding, they used a new method that could also be applied to learn about the atmospheres of gas-dominated planets outside our solar system. Described in a paper in the journal Science, the work combines observations by a group of radio telescopes with data from NASA's recently retired infrared observatory, the Spitzer Space Telescope, managed by the agency's Jet Propulsion Laboratory in Southern California. Officially named 2MASS J10475385+2124234, the target of the new study was located 32 light-years from Earth - a stone's throw away, cosmically speaking. It is one of the coldest known brown dwarfs.. The researchers detected winds moving around the planet at 1,425 mph (2,293 kph). For comparison, Neptune's atmosphere features the fastest winds in the solar system, which whip through at more than 1,200 mph (about 2,000 kph).

This image from NASA's Spitzer Space Telescope shows the Tarantula Nebula in two wavelengths of infrared light, each represented by a different color. The red color at the heart of the nebula shows the presence of particularly hot gas emitting infrared light at a wavelength of 4.5 micrometers. The blue regions are dust composed of molecules called polycyclic aromatic hydrocarbons (PAHs), which are also found in ash from coal, wood and oil fires on Earth. Regions emitting both wavelengths appear white. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

This image shows the location of Supernova 1987A and the starburst region R136 where massive stars form at a significantly higher rate than anywhere else in the galaxy. NASA's Spitzer Space Telescope shows the Tarantula Nebula in three wavelengths of infrared light, each represented by a different color. The magenta-colored regions are dust composed of molecules called polycyclic aromatic hydrocarbons (PAHs), which are also found in ash from coal, wood and oil fires on Earth. PAHs emit in multiple wavelengths. The PAHs emit in multiple wavelengths, so the magenta color is a combination of red (corresponding to an infrared wavelength of 8 micrometers) and blue (3.6 micrometers). The green color in this image shows the presence of particularly hot gas emitting infrared light at a wavelength of 4.5 micrometers. The stars in the image are mostly a combination of green and blue. White hues indicate regions that radiate in all three wavelengths. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

This image from NASA's Spitzer Space Telescope shows the Tarantula Nebula in three wavelengths of infrared light, each represented by a different color. The magenta-colored regions are dust composed of molecules called polycyclic aromatic hydrocarbons (PAHs), which are also found in ash from coal, wood and oil fires on Earth. PAHs emit in multiple wavelengths. The PAHs emit in multiple wavelengths, so the magenta color is a combination of red (corresponding to an infrared wavelength of 8 micrometers) and blue (3.6 micrometers). The green color in this image shows the presence of particularly hot gas emitting infrared light at a wavelength of 4.5 micrometers. The stars in the image are mostly a combination of green and blue. White hues indicate regions that radiate in all three wavelengths. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

This carved-out cloud of gas and dust has been nicknamed the "Jack-o'-lantern Nebula" because it looks like a cosmic hollowed-out pumpkin. Powerful outflows of radiation and particles from a massive star known as an O-type star and about 15 to 20 times heavier than the Sun has likely swept the surrounding dust and gas outward, creating deep gouges in the cloud. The image shows infrared light (which is invisible to the human eye) captured by NASA's Spitzer Space Telescope. This image features three wavelengths of infrared light. Green and red represent wavelengths emitted primarily by dust radiating at different temperatures, though some stars radiate prominently in these wavelengths as well. The combination of green and red in the image creates yellow hues. Blue represents a wavelength emitted, in this image, mostly by stars and some very hot regions of the nebula. White regions are where the objects are bright in all three colors. The O-type star appears as a white spot at the center of a red dust shell near the middle of the scooped-out region. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

This carved-out cloud of gas and dust has been nicknamed the "Jack-o'-lantern Nebula" because it looks like a cosmic hollowed-out pumpkin. Powerful outflows of radiation and particles from a massive star known as an O-type star and about 15 to 20 times heavier than the Sun has likely swept the surrounding dust and gas outward, creating deep gouges in the cloud. The image shows infrared light (which is invisible to the human eye) captured by NASA's Spitzer Space Telescope. This image is a high-contrast version in which the red wavelength is more pronounced. Together, the red and green wavelengths create an orange hue. The picture highlights contours in the dust as well as the densest regions of the nebula, which appear brightest. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

This image shows data from NASA's Spitzer Space Telescope, from the IRAC instrument, with colors corresponding to wavelengths of 3.6, 4.5, 5.8 and 8.0 m (shown as blue, green, orange and red). The grand red delta filling most of the image is a far-away nebula, or a cloud of gas and dust. A second nebula is located in the lower right portion of the image. Within the first nebula, on the left side of this image, a dark filament runs horizontally through the green cloud. A smattering of baby stars (the red and yellow dots) appear inside it. Known as Cepheus C, the area is a particularly dense concentration of gas and dust where infant stars form. This region is called Cepheus C because it lies in the constellation Cepheus, which can be found near the constellation Cassiopeia. Cepheus-C is about 6 light years long, and lies about 40 light-years from the bright spot at the tip of the nebula. Two features identified in the annotated image are visible only in the multi-instrument version of the image. The first is V374 Ceph in the larger nebula. The second is the "runaway star" in the smaller nebula. A second star cluster is located just above the second large nebula on the right side of the image. Known as Cepheus B, the cluster sits within a few thousand light-years of our Sun. A study of this region using Spitzer found that the dramatic collection is about 4 million to 5 million years old ?? slightly older than those in Cepheus C. Also found in the second nebula is a small cluster of newborn stars that illuminates the dense cloud of gas and dust where they formed. It appears as a bright teal splash. In 2017 and 2016, high school students and teachers contributed to our understanding of the Cepheus C star-forming region. As part of NITARP (NASA/IPAC Teacher Archive Research Program), the students and teachers combed through Spitzer data to identify the presence of young stellar objects. Over two years, the students and teachers identified more than 100 such objects that hadn't been identified in previous studies. Astronomer Luisa Rebull of IPAC at Caltech guided the students and teachers. Educators interested in participating in NITARP should visit the program website. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This image was compiled using data from NASA's Spitzer Space Telescope using the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS) during Spitzer's "cold" mission, before the spacecraft's liquid helium coolant ran out in 2009. The colors correspond with IRAC wavelengths of 3.6 microns (blue), 4.5 microns (cyan) and 8 microns (green), and 24 microns (red) from the MIPS instrument. The green-and-orange delta filling most of this image is a nebula, or a cloud of gas and dust. This region formed from a much larger cloud of gas and dust that has been carved away by radiation from stars. The bright region at the tip of the nebula is dust that has been heated by the stars' radiation, which creates the surrounding red glow. The white color is the combination of four colors (blue, green, orange and red), each representing a different wavelength of infrared light, which is invisible to human eyes. The massive stars illuminating this region belong to a star cluster that extends above the white spot. On the left side of this image, a dark filament runs horizontally through the green cloud. A smattering of baby stars (the red and yellow dots) appear inside it. Known as Cepheus C, the area is a particularly dense concentration of gas and dust where infant stars form. This region is called Cepheus C because it lies in the constellation Cepheus, which can be found near the constellation Cassiopeia. Cepheus-C is about 6 light-years long, and lies about 40 light-years from the bright spot at the tip of the nebula. The small, red hourglass shape just below Cepheus C is V374 Ceph. Astronomers studying this massive star have speculated that it might be surrounded by a nearly edge-on disk of dark, dusty material. The dark cones extending to the right and left of the star are a shadow of that disk. The smaller nebula on the right side of the image includes a blue star crowned by a small, red arc of light. This "runaway star" is plowing through the gas and dust at a rapid clip, creating a shock wave or "bow shock" in front of itself. Some features identified in the annotated image are more visible in the IRAC data alone. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This image shows data from NASA's Spitzer Space Telescope, from the IRAC instrument, with colors corresponding to wavelengths of 3.6, 4.5, 5.8 and 8.0 m (shown as blue, green, orange and red). The grand red delta filling most of the image is a far-away nebula, or a cloud of gas and dust. A second nebula is located in the lower right portion of the image. Within the first nebula, on the left side of this image, a dark filament runs horizontally through the green cloud. A smattering of baby stars (the red and yellow dots) appear inside it. Known as Cepheus C, the area is a particularly dense concentration of gas and dust where infant stars form. This region is called Cepheus C because it lies in the constellation Cepheus, which can be found near the constellation Cassiopeia. Cepheus-C is about 6 light years long, and lies about 40 light-years from the bright spot at the tip of the nebula. Two features identified in the annotated image are visible only in the multi-instrument version of the image. The first is V374 Ceph in the larger nebula. The second is the "runaway star" in the smaller nebula. A second star cluster is located just above the second large nebula on the right side of the image. Known as Cepheus B, the cluster sits within a few thousand light-years of our Sun. A study of this region using Spitzer found that the dramatic collection is about 4 million to 5 million years old ?? slightly older than those in Cepheus C. Also found in the second nebula is a small cluster of newborn stars that illuminates the dense cloud of gas and dust where they formed. It appears as a bright teal splash. In 2017 and 2016, high school students and teachers contributed to our understanding of the Cepheus C star-forming region. As part of NITARP (NASA/IPAC Teacher Archive Research Program), the students and teachers combed through Spitzer data to identify the presence of young stellar objects. Over two years, the students and teachers identified more than 100 such objects that hadn't been identified in previous studies. Astronomer Luisa Rebull of IPAC at Caltech guided the students and teachers. Educators interested in participating in NITARP should visit the program website. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This image was compiled using data from NASA's Spitzer Space Telescope using the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS) during Spitzer's "cold" mission, before the spacecraft's liquid helium coolant ran out in 2009. The colors correspond with IRAC wavelengths of 3.6 microns (blue), 4.5 microns (cyan) and 8 microns (green), and 24 microns (red) from the MIPS instrument. The green-and-orange delta filling most of this image is a nebula, or a cloud of gas and dust. This region formed from a much larger cloud of gas and dust that has been carved away by radiation from stars. The bright region at the tip of the nebula is dust that has been heated by the stars' radiation, which creates the surrounding red glow. The white color is the combination of four colors (blue, green, orange and red), each representing a different wavelength of infrared light, which is invisible to human eyes. The massive stars illuminating this region belong to a star cluster that extends above the white spot. On the left side of this image, a dark filament runs horizontally through the green cloud. A smattering of baby stars (the red and yellow dots) appear inside it. Known as Cepheus C, the area is a particularly dense concentration of gas and dust where infant stars form. This region is called Cepheus C because it lies in the constellation Cepheus, which can be found near the constellation Cassiopeia. Cepheus-C is about 6 light-years long, and lies about 40 light-years from the bright spot at the tip of the nebula. The small, red hourglass shape just below Cepheus C is V374 Ceph. Astronomers studying this massive star have speculated that it might be surrounded by a nearly edge-on disk of dark, dusty material. The dark cones extending to the right and left of the star are a shadow of that disk. The smaller nebula on the right side of the image includes a blue star crowned by a small, red arc of light. This "runaway star" is plowing through the gas and dust at a rapid clip, creating a shock wave or "bow shock" in front of itself. Some features identified in the annotated image are more visible in the IRAC data alone. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This image from NASA's Spitzer Space Telescope shows the elliptical galaxy Messier 87 (M87), the home galaxy of the supermassive black hole recently imaged by the Event Horizon Telescope (EHT). Spitzer's infrared view shows a faint trace of a jet of material spewing to the right of the galaxy - a feature that was previously one key indicator that a supermassive black hole lived at the galaxy's center. More prominent in the image is the shockwave created by that jet. The inset in the image below shows a close-up view of the shockwave on the right side of the galaxy, as well as the shockwave from a second jet traveling to the left of the galaxy. Located about 55 million light-years from Earth, M87 has been a subject of astronomical study for more than 100 years and has been imaged by many NASA observatories, including the Hubble Space Telescope, the Chandra X-ray Observatory and NuSTAR. In 1918, astronomer Heber Curtis first noticed "a curious straight ray" extending from the galaxy's center. This bright jet (which appears to extend to the right of the galaxy) is visible in multiple wavelengths of light, from radio waves through X-rays. The jet is produced by a disk of material spinning rapidly around the black hole, and spewing in opposite directions away from the galaxy. When the particles in the jet impact the interstellar medium (the sparse material filling the space between stars in M87), they create a shockwave that radiates in infrared and radio wavelengths of light, but not visible light. The jet on the right is traveling almost directly toward Earth, and its brightness is amplified due to its high speed in our direction. But the jet's trajectory is just slightly offset from our line of sight with the galaxy, so we can still see some of the length of the jet. The shockwave begins around the point where the jet appears to curve down, highlighting the regions where the fast-moving particles are colliding with gas in the galaxy and slowing down. There is also a second jet on the left that is moving so rapidly away from us it is rendered invisible at all wavelengths. But the shockwave it creates in the interstellar medium can still be seen here. In the Spitzer image, the shockwave is on the left side of the galaxy and looks like an inverted letter "C." This image from NASA's Spitzer Space Telescope shows M87 looks like a hazy, blue space-puff. At the galaxy's center is a supermassive black hole that spews two jets of material out into space. This image shows a wide-field image of M87, also taken by NASA's Spitzer Space Telescope. The top inset shows a close-up of two shockwaves, created by a jet emanating from the galaxy's supermassive black hole. The Event Horizon Telescope recently took a close-up image of the silhouette of that black hole, shown in the second inset. Scientists are still striving for a solid theoretical understanding of how inflowing gas around black holes creates outflowing jets. Infrared light at wavelengths of 3.4 and 4.5 microns are rendered in blue and green, showing the distribution of stars, while dust features that glow brightly at 8.0 microns are shown in red. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This image from NASA's Spitzer Space Telescope shows the elliptical galaxy Messier 87 (M87), the home galaxy of the supermassive black hole recently imaged by the Event Horizon Telescope (EHT). Spitzer's infrared view shows a faint trace of a jet of material spewing to the right of the galaxy - a feature that was previously one key indicator that a supermassive black hole lived at the galaxy's center. More prominent in the image is the shockwave created by that jet. The inset in the image below shows a close-up view of the shockwave on the right side of the galaxy, as well as the shockwave from a second jet traveling to the left of the galaxy. Located about 55 million light-years from Earth, M87 has been a subject of astronomical study for more than 100 years and has been imaged by many NASA observatories, including the Hubble Space Telescope, the Chandra X-ray Observatory and NuSTAR. In 1918, astronomer Heber Curtis first noticed "a curious straight ray" extending from the galaxy's center. This bright jet (which appears to extend to the right of the galaxy) is visible in multiple wavelengths of light, from radio waves through X-rays. The jet is produced by a disk of material spinning rapidly around the black hole, and spewing in opposite directions away from the galaxy. When the particles in the jet impact the interstellar medium (the sparse material filling the space between stars in M87), they create a shockwave that radiates in infrared and radio wavelengths of light, but not visible light. The jet on the right is traveling almost directly toward Earth, and its brightness is amplified due to its high speed in our direction. But the jet's trajectory is just slightly offset from our line of sight with the galaxy, so we can still see some of the length of the jet. The shockwave begins around the point where the jet appears to curve down, highlighting the regions where the fast-moving particles are colliding with gas in the galaxy and slowing down. There is also a second jet on the left that is moving so rapidly away from us it is rendered invisible at all wavelengths. But the shockwave it creates in the interstellar medium can still be seen here. In the Spitzer image, the shockwave is on the left side of the galaxy and looks like an inverted letter "C." This image from NASA's Spitzer Space Telescope shows M87 looks like a hazy, blue space-puff. At the galaxy's center is a supermassive black hole that spews two jets of material out into space. This image shows a wide-field image of M87, also taken by NASA's Spitzer Space Telescope. The inset shows a close-up of two shockwaves, created by a jet emanating from the galaxy's supermassive black hole. Scientists are still striving for a solid theoretical understanding of how inflowing gas around black holes creates outflowing jets. Infrared light at wavelengths of 3.4 and 4.5 microns are rendered in blue and green, showing the distribution of stars, while dust features that glow brightly at 8.0 microns are shown in red. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This image from NASA's Spitzer Space Telescope shows the elliptical galaxy Messier 87 (M87), the home galaxy of the supermassive black hole recently imaged by the Event Horizon Telescope (EHT). Spitzer's infrared view shows a faint trace of a jet of material spewing to the right of the galaxy - a feature that was previously one key indicator that a supermassive black hole lived at the galaxy's center. More prominent in the image is the shockwave created by that jet. The inset in the image below shows a close-up view of the shockwave on the right side of the galaxy, as well as the shockwave from a second jet traveling to the left of the galaxy. Located about 55 million light-years from Earth, M87 has been a subject of astronomical study for more than 100 years and has been imaged by many NASA observatories, including the Hubble Space Telescope, the Chandra X-ray Observatory and NuSTAR. In 1918, astronomer Heber Curtis first noticed "a curious straight ray" extending from the galaxy's center. This bright jet (which appears to extend to the right of the galaxy) is visible in multiple wavelengths of light, from radio waves through X-rays. The jet is produced by a disk of material spinning rapidly around the black hole, and spewing in opposite directions away from the galaxy. When the particles in the jet impact the interstellar medium (the sparse material filling the space between stars in M87), they create a shockwave that radiates in infrared and radio wavelengths of light, but not visible light. The jet on the right is traveling almost directly toward Earth, and its brightness is amplified due to its high speed in our direction. But the jet's trajectory is just slightly offset from our line of sight with the galaxy, so we can still see some of the length of the jet. The shockwave begins around the point where the jet appears to curve down, highlighting the regions where the fast-moving particles are colliding with gas in the galaxy and slowing down. There is also a second jet on the left that is moving so rapidly away from us it is rendered invisible at all wavelengths. But the shockwave it creates in the interstellar medium can still be seen here. In the Spitzer image, the shockwave is on the left side of the galaxy and looks like an inverted letter "C." This image from NASA's Spitzer Space Telescope shows M87 looks like a hazy, blue space-puff. At the galaxy's center is a supermassive black hole that spews two jets of material out into space. This image shows a wide-field image of M87, also taken by NASA's Spitzer Space Telescope. Scientists are still striving for a solid theoretical understanding of how inflowing gas around black holes creates outflowing jets. Infrared light at wavelengths of 3.4 and 4.5 microns are rendered in blue and green, showing the distribution of stars, while dust features that glow brightly at 8.0 microns are shown in red. The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

This graph presents known properties of the seven TRAPPIST-1 exoplanets (labeled b through h), showing how they stack up to the inner rocky worlds in our own solar system. The horizontal axis shows the level of illumination that each planet receives from its host star. TRAPPIST-1 is a mere 9 percent the mass of our Sun, and its temperature is much cooler. But because the TRAPPIST-1 planets orbit so closely to their star, they receive comparable levels of light and heat to Earth and its neighboring planets. The vertical axis shows the densities of the planets. Density, calculated based on a planet's mass and volume, is the first important step in understanding a planets composition. The plot shows that the TRAPPIST-1 planet densities range from being similar to Earth and Venus at the upper end, down to values comparable to Mars at the lower end. The relative sizes of the planets are indicated by the circles. The masses and densities of the TRAPPIST-1 planets were determined by careful measurements of slight variations in the timings of their orbits using extensive observations made by NASAs Spitzer and Kepler space telescopes, in combination with data from Hubble and a number of ground-based telescopes. These measurements are the most precise to date for any system of exoplanets. By comparing these measurements with theoretical models of how planets form and evolve, researchers have determined that they are all rocky in overall composition. Estimates suggest the lower-density planets could have large quantities of water -- as much as 5 percent by mass for TRAPPIST-1d. Earth, in comparison, has only about 0.02 percent of its mass in the form of water.

This artist's concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets' diameters, masses and distances from the host star, as of February 2018. This image represents an updated version of one originally created in 2017. The planets' appearances were re-imagined based on a 2018 study using additional observations from NASA's Spitzer and Kepler space telescopes, in addition to previous data from Spitzer, the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope and other ground-based observatories. The system was named for the TRAPPIST telescope. The new analysis concludes that the seven planets of TRAPPIST-1 are all rocky, and some could contain significant amounts of water. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. The form that water would take on TRAPPIST-1 planets would depend on the amount of heat they receive from their star, which is a mere 9 percent as massive as our Sun. Planets closest to the star are more likely to host water in the form of atmospheric vapor, while those farther away may have water frozen on their surfaces as ice. TRAPPIST-1e is the rockiest planet of them all, but still is believed to have the potential to host some liquid water. In this illustration, the relative sizes of the planets and their host star, an ultracool dwarf, are all shown to scale.

This artist's concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets' diameters, masses and distances from the host star, as of February 2018. This image represents an updated version of one originally created in 2017. The planets' appearances were re-imagined based on a 2018 study using additional observations from NASA's Spitzer and Kepler space telescopes, in addition to previous data from Spitzer, the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope and other ground-based observatories. The system was named for the TRAPPIST telescope. The new analysis concludes that the seven planets of TRAPPIST-1 are all rocky, and some could contain significant amounts of water. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. The form that water would take on TRAPPIST-1 planets would depend on the amount of heat they receive from their star, which is a mere 9 percent as massive as our Sun. Planets closest to the star are more likely to host water in the form of atmospheric vapor, while those farther away may have water frozen on their surfaces as ice. TRAPPIST-1e is the rockiest planet of them all, but still is believed to have the potential to host some liquid water. In this illustration, the relative sizes of the planets and their host star, an ultracool dwarf, are all shown to scale.

This illustration shows the seven Earth-size planets of TRAPPIST-1, an exoplanet system about 40 light-years away, based on data current as of February 2018. The image shows the planets relative sizes but does not represent their orbits to scale. The art highlights possibilities for how the surfaces of these intriguing worlds might look based on their newly-calculated properties. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it.

All seven planets discovered in orbit around the red dwarf star TRAPPIST-1 could easily fit inside the orbit of Mercury, the innermost planet of our solar system. In fact, they would have room to spare. TRAPPIST-1 also is only a fraction of the size of our Sun; it isn't much larger than Jupiter. So, the TRAPPIST-1 system's proportions look more like Jupiter and its moons than those of our solar system. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. This image has artwork updated in Feb. 2018 to reflect surfaces based on more precise measurements of the planets' densities.

This artist's concept shows an exoplanet and debris disk orbiting a polluted white dwarf. White dwarfs are dim, dense remnants of stars similar to the Sun that have exhausted their nuclear fuel and blown off their outer layers. By "pollution," astronomers mean heavy elements invading the photospheres -- the outer atmospheres -- of these stars. The leading explanation is that exoplanets could push small rocky bodies toward the star, whose powerful gravity would pulverize them into dust. That dust, containing heavy elements from the torn-apart body, would then fall on the star. NASA's Spitzer Space Telescope has been instrumental in expanding the field of polluted white dwarfs orbited by hot, dusty disks. Since launch in 2004, Spitzer has confirmed about 40 of these special stars. Another space telescope, NASA's Wide-field Infrared Survey Explorer (WISE), also detected a handful, bringing the total up to about four dozen known today. Because these objects are so faint, infrared light is crucial to identifying them.

This illustration depicts a hypothetical uneven ring of dust orbitingKIC 8462852, also known as Boyajians Star or Tabby's Star. Astronomers have found the dimming of the star over long periods appears to be weaker at longer infrared wavelengths of light and stronger at shorter ultraviolet wavelengths. Such reddening is characteristic of dust particles and inconsistent with more fanciful alien megastructure concepts, which would evenly dim all wavelengths of light. By studying observations from NASAsSpitzer and Swift telescopes, as well as the Belgian AstroLAB IRIS observatory, the researchers have been able to better constrain the size of the dust particles. This places them within the range found in dust disks orbiting stars, and larger than the particles typically found in interstellar dust. The system is portrayed with a couple of comets, consistent with previous studies that have found evidence for cometary activity within the system.

In the summer of the year 1054 AD, Chinese astronomers saw a new "guest star," that appeared six times brighter than Venus. So bright in fact, it could be seen during the daytime for several months. This "guest star" was forgotten about until 700 years later with the advent of telescopes. Astronomers saw a tentacle-like nebula in the place of the vanished star and called it the Crab Nebula. Today we know it as the expanding gaseous remnant from a star that self-detonated as a supernova, briefly shining as brightly as 400 million suns. The explosion took place 6,500 light-years away. If the blast had instead happened 50 light-years away it would have irradiated Earth, wiping out most life forms. In the late 1960s astronomers discovered the crushed heart of the doomed star, an ultra-dense neutron star that is a dynamo of intense magnetic field and radiation energizing the nebula. Astronomers therefore need to study the Crab Nebula across a broad range of electromagnetic radiation, from X-rays to radio waves. This image combines data from five different telescopes: the VLA (radio) in red; Spitzer Space Telescope (infrared) in yellow; Hubble Space Telescope (visible) in green; XMM-Newton (ultraviolet) in blue; and Chandra X-ray Observatory (X-ray) in purple. The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington, D.C. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations. NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.