Image of the Week

9 July 2025: The Fighting Dragons of Ara, formally designated NGC 6188, is an emission nebula located about 4000 light-years away near the edge of a large molecular cloud in the constellation Ara (the Altar). The nebula was given its name for its resemblance to two ‘dragons’ emerging from within the ominous dark dust clouds to face off with one another. This image is of their ‘profiles’ pointed squarely at each other, captured by the DOE-built Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at the U.S. National Science Foundation Cerro Tololo Inter-American Observatory, a Program of NSF NOIRLab. The reddish glow of the dragons’ backs is ionized hydrogen, ‘lit up’ by light from the bright young stars — only a few million years old — in the nebula. Of these young stars, 27 form the beaming open cluster NGC 6193 (in the upper left quadrant of the image, …

2 July 2025: The silhouette of the Víctor M. Blanco 4-meter Telescope appears as just a speck in this panoramic sunset image of Cerro Tololo, home to the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. CTIO is a collection of telescopes and instruments located on the Cerro Tololo and Cerro Pachón mountains in Chile. CTIO and the Blanco Telescope are located at an altitude of approximately 2200 meters (7200 feet). The Blanco Telescope is used to carry out the Dark Energy Survey (DES), a project supported in part by the U.S. Department of Energy (DOE) Office of Science. The goal of DES is to map galaxies, detect supernovae, and find patterns of cosmic structure that will reveal the nature of dark energy, a mysterious influence thought to be driving the accelerated expansion of the Universe. Astronomers believe around 70% of the Universe may exist in the …

25 June 2025: Like many observatories, Gemini North sits in a remote area of the world to avoid the adverse effects of light pollution (the artificial brightening of the night sky often caused by the lighting in urban and suburban areas). Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab, more specifically sits near the summit of Maunakea in Hawai‘i, high above the layers of clouds that act like an extra shield from city lights below. However, a different artificial light source can affect geographically protected telescopes: satellite constellations. To the right of Gemini North in this Image of the Week, satellite flares form a triangle under the Milky Way. Although this long-exposure image appears to capture a clear night sky, telescopes are typically a billion times more sensitive than the human eye. The majority of satellite constellations are …

18 June 2025: Laser light and star trails combine for a cosmic light show at Gemini North, one half of the International Gemini Observatory which is supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab, on Maunakea in Hawai‘i. This scene was created by combining multiple timelapse images. In the foreground sits Gemini North, situated near the highest point in the Pacific Basin at an altitude of 4213 meters (13,822 feet). The orange streaks were created by Gemini’s Laser Guide Star (LGS) system at several different observing positions. The laser creates an ‘artificial star’ by interacting with atoms in the upper atmosphere approximately 90 kilometers (50 miles) above the Earth. Earth’s atmosphere distorts light from the laser-created ‘star’, just as it distorts the light from objects under study. By measuring these distortions, Gemini’s adaptive optics system can correct for them in the telescope’s science observations, resulting in crisper, …

11 June 2025: This Image of the Week contrasts the beautiful curve of the Milky Way with the geometric architecture of NSF's recently retired McMath-Pierce Solar Telescope at the U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, near Tucson, Arizona. The McMath-Pierce Solar Telescope was once the largest solar telescope in the world, standing 33 meters (110 feet) tall with a 60-meter (200-foot) long diagonal shaft that continues underground. As a reflecting telescope, this instrument relied on mirrors to see the skies, and its diagonal bend led towards its 1.6-meter-diameter primary mirror. Soon the public will have the unique opportunity to visit the McMath-Pierce Solar Telescope in a brand new guise, as it is being transformed into a dynamic astronomy education center. NSF’s new Windows on the Universe Center for Astronomical Outreach at Kitt Peak will allow the public to experience the cutting-edge research carried out at …

4 June 2025: Another night of observing begins at the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO) in the Chilean Andes, a Program of NSF NOIRLab. The Moon appears massive as it rises above the SMARTS–GSU 0.9-meter Telescope on the left, the SMARTS–GSU 1.5-meter Telescope in the center, and the Víctor M. Blanco 4-meter Telescope on the right. Both the SMARTS-GSU telescopes are operated by the Georgia State University Research Foundation. Since ancient times the Moon has been recorded to appear larger when it rests near the horizon. Although some camera lens magic is at work in this Image of the Week, this is a real phenomenon that humans experience, known as the Moon illusion. It is entirely an optical illusion produced by the human brain! To prove the Moon is not actually bigger when it’s near the horizon, extend your thumb towards the Moon when it is high in the …

28 May 2025: A fireball streaks across the morning sky above NSF Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab funded by the U.S. National Science Foundation. The sky is filled with blue-green airglow while the Sun starts to brighten the night from the east. At the bottom center of this photo the constellation Orion rises above the KPNO 2.1-meter Telescope, one of the earliest telescopes on the KPNO site. Fireballs are exceptionally bright meteors that, like all meteors, heat up when they enter Earth's atmosphere at high velocities and leave a trail of glowing material in the sky. Meteors are classified as fireballs when they shine brighter than the planets, which is an apparent magnitude of –4 or brighter. Located west of Tucson, Arizona in the Sonoran Desert, Kitt Peak benefits from exceptionally dark skies, allowing celestial phenomena like fireballs to stand out more vividly. Its high elevation minimizes atmospheric …

21 May 2025: This Image of the Week features Gemini North, located on Maunakea in Hawai‘i, on the far right of the panorama. Gemini North is one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. In the center, a pastel sunset retreats under the glowing arch of the Milky Way. Also witnessing this picturesque sky is the United Kingdom Infrared Telescope (UKIRT) on the left side. Projecting up from the horizon to ‘cut’ through the Milky Way is the zodiacal light, a faint glow caused by sunlight scattered by interplanetary dust. Try zooming in to look at the details of the landscape and the telescopes. The Milky Way is shaped like a disk, but appears straight when we look at a small portion in the sky. In this extremely wide-angle image the Milky Way appears as an arch because of the …

14 May 2025: Dawn breaks behind the mountain of Cerro Tololo, bringing with it another day full of discoveries. This Image of the Week captures a panoramic view of the Belt of Venus rising behind instruments of the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab, in Chile. Contrary to the name, the Belt of Venus has nothing to do with the planet Venus. It refers to an atmospheric effect occurring before sunrise and sunset. The sky opposite the rising or setting Sun is illuminated by limited sunlight. As the light travels through the atmosphere, its bluer wavelengths are scattered and diffused more than its redder ones. The red light is then reflected back towards the viewer, leaving the reddish belt seen across the sky. While the planet Venus (also known as the ‘morning star’ or the ‘evening star’) is often seen at the same time as …

7 May 2025: A SpaceX Falcon 9 rocket lights up the sky as seen in this image taken last summer from the U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, near Tucson, Arizona. Although the rocket lifted off from Vandenberg Space Force Base about 890 kilometers (550 miles) away in California, the recently set Sun lit up the rocket’s exhaust plume for miles as the plume dramatically expanded in Earth’s upper atmosphere. With 23 optical and two radio telescopes, Kitt Peak National Observatory is the largest, most diverse gathering of astronomical instruments in the northern hemisphere. The observatory is located in Arizona’s Quinlan mountains in the Schuk Toak District on the Tohono O'odham Nation. In the foreground of this image is the 0.9-meter SARA Kitt Peak Telescope operated by the Southeastern Association for Research in Astronomy (SARA). KPNO offers daytime and nighttime public tours where visitors can …

30 April 2025: Punctuating the deep black of this Image of the Week are hundreds of blobs of light, each one an entire galaxy in our Universe. Many of the yellowish points are members of the galaxy cluster Abell 1489, imaged here using the Gemini Multi-Object Spectrograph (GMOS) on Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. Galaxy clusters are immense neighborhoods of galaxies gravitationally bound together. These massive formations serve as tools for astronomers to understand the Universe’s dark matter distribution, structure, and overall evolution. Astronomers classify galaxy clusters in several ways and have compiled multiple catalogs of clusters. This particular cluster has been labeled using the Abell classification scheme. Within this scheme, clusters are mainly sorted by their richness — the number of galaxies they contain — and their distance from us. Abell 1489 was categorized …

23 April 2025: No, you are not seeing double in this panorama of telescopes that make up the SMARTS (Small and Moderate Aperture Research Telescope System) Consortium at the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. Though they look similar from the outside, the SMARTS–GSU 0.9-meter Telescope (left) and the SMARTS–GSU 1.5-meter Telescope (right) have slightly different observing roles. The SMARTS–GSU 1.5-meter telescope hosts a special instrument called CHIRON. This spectrograph measures precise radial velocities to confirm the existence of stellar companions. The SMARTS–GSU 0.9-meter telescope, on the other hand, is fitted with the Tek2K instrument, a charge-coupled device (CCD) used for creating astronomical images. Both the SMARTS–GSU 0.9-meter and the SMARTS–GSU 1.5-meter are primarily used for the RECONS (REsearch Consortium On Nearby Stars) program, which measures the distances to nearby stars and detects unseen companions by using a variety of observational techniques. RECONS has been …

16 April 2025: Countless star trails appear as colorful brushstrokes spread across the night sky above NSF–DOE Vera C. Rubin Observatory, jointly funded by the U.S. National Science Foundation (NSF) and the U.S. Department of Energy (DOE) Office of Science. This mesmerizing image was created using long-exposure photography, a technique in which a photographer allows light to enter their camera lens for a period of several minutes to several hours. The camera captures the subject’s movements, and the resulting image shows the flow of time in a single shot. During its decade-long Legacy Survey of Space and Time (LSST) Rubin will use a technique known as difference imaging: equipped with the largest camera ever built, Rubin will image the southern sky every few nights. Scientists will stack the best images in each filter each year into ultra-long exposures and create template images of the southern sky. When this template is compared to individual …

9 April 2025: Pictured here under a moonlit sky, high on the slopes of Maunakea, are two of the world’s most advanced astronomical observatories. In the foreground is the iconic dome of Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab, and in the background is the Canada-France-Hawaii Telescope. In the upper right corner of the image is the Moon blazing with reflected sunlight. Astronomers have a complex relationship with the Moon. Studying it has offered insights into the early Solar System and the history of Earth. The Moon is a familiar object that drives interest in astronomy as it is usually the first object observed by young people and it’s easy for anyone to observe. As a result, it is frequently used in public engagement programs. However, it’s a hindrance to many types of observations because of the …

2 April 2025: This Image of the Week captures the mesmerizing Geminids meteor shower above the NSF McMath Pierce Solar Telescope at U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, as the Milky Way rises high into the sky. The annual Geminids shower happens when Earth passes through the debris trail of asteroid 3200 Phaethon in December and this debris collides with our atmosphere to then explode into fiery streaks of light. The Geminids is unusual among meteor showers because it is one of two major showers not caused by a comet. Two telescopes at KPNO are used to study asteroids: the UArizona 0.9-meter and 1.8-meter Spacewatch telescopes. The University of Arizona’s Spacewatch Program was founded to explore the various populations of small objects in the Solar System and study the statistics of asteroids and comets to investigate the dynamical evolution of the Solar System. The decommissioned …

26 March 2025: In an alignment of celestial bodies, Mars was captured here rising out of a lunar occultation on 13 January 2025 using the new Visitor Center 0.6-meter Shreve Telescope at the U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, near Tucson, Arizona. An occultation is when an object becomes hidden from an observer’s view by another object passing between them. The passing object must be larger than the hidden object. Otherwise the event is a transit, such as the transit of Mercury in front of the Sun in 2019, as photographed from NSF Cerro Tololo International Observatory (CTIO), another Program of NSF NOIRLab. Three days after this photo was taken, Mars was in opposition to the Sun from our point of view on Earth, so coming out of occultation the red planet was almost fully sunlit and appeared brighter and bigger than usual. Two evening …

19 March 2025: During the night of 13 to 14 March 2025, the sky was embellished by this total lunar eclipse. Lunar eclipses occur when Earth is positioned between the Sun and the Moon. In this position, the Moon enters Earth’s shadow as Earth prevents the Sun’s light from reaching the Moon directly. In this alignment, the Moon isn’t completely dark — instead, it is drenched in a red glow, as some sunlight passes through Earth’s atmosphere to reach the Moon. Rayleigh scattering of the sunlight in Earth’s atmosphere causes this ‘bloody’ color by scattering the light with shorter, bluer wavelengths more from their path than light of longer, redder wavelengths. NOIRLab's photo ambassador, Petr Horálek, captured the phenomenon at NSF Cerro Tololo Inter-American Observatory (CTIO) in Chile. This composite image — which was selected as Astronomy Picture of the Day 15 March 2025 — records the progression of the eclipse. Another photographer …

12 March 2025: Have you ever wished upon a shooting star? Shooting stars are not actually stars at all, but are seen when small rocks from space, called meteoroids, smash through the Earth’s atmosphere. The rocks as they pass through the atmosphere cause a streak of light and become a meteor. This photographer was lucky enough to capture a meteor here in this image of Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. Easily visible meteors are often part of large showers that occur when Earth passes through the trail of debris left by a comet and appear in rapid succession in the night sky. These meteor showers happen at specific times of the year and last for predictable periods of time. Lone meteors, like the green streak in the upper center of this image, are random events …

5 March 2025: Arizona’s night skies are perfect for stargazing, thanks to infrequent clouds, high elevation, and strict light pollution controls. This breathtaking shot shows the Milky Way above U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab. KPNO is the largest assembly of optical instruments in the northern hemisphere and is a leading site for astronomical research. The Burrell Schmidt telescope on the left was relocated to KPNO from Case Western Reserve University to escape the increasing light pollution in Cleveland, Ohio. In the middle is the 0.9-meter SARA Kitt Peak Telescope. It was originally known as the No. 1 36-inch telescope of the predecessor of NOIRLab, National Optical Astronomy Observatories (NOAO), but today the telescope is operated by the Southeastern Association for Research in Astronomy, a consortium of universities throughout the southeast United States. This group combines their resources to support astronomical research by their faculty …

26 February 2025: The Milky Way shares the stage with a luminous bubble of green and orange airglow in this panoramic image of Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation (NSF) and operated by NSF NOIRLab. Gemini North (right) is accompanied here by the Canada-France-Hawai‘i Telescope (CFHT) (left). In this image, you could remove all of the stars, the brilliant stripe of the Milky Way, and the nearby city lights of Hilo, Hawai‘i (far left), and you would still be left with a picture that isn’t completely dark. This is thanks to the persistent light of airglow. Airglow is primarily caused by sunlight interacting with atoms and molecules in Earth’s upper atmosphere, which allows them to gain excess energy. This excess energy is then released as a particle of light called a photon. The frequencies of the photons determine the captivating colors …