Stars are forming in Lynds Dark Nebula (LDN) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, the dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare region. Across the spectrum, astronomical explorations of the obscuring interstellar clouds reveal energetic shocks and outflows associated with newborn stars, including the telltale reddish glow from scattered Herbig-Haro objects seen in this sharp image. Distant background galaxies also lurk on the scene, visually buried behind the dusty expanse. The deep telescopic field of view imaged with broadband filters spans about two full moons on the sky, or 17 light-years at the estimated distance of LDN 1251.
Why do some spiral galaxies have a ring around the center? First and foremost, M95 is one of the closer examples of a big and beautiful barred spiral galaxy. Visible in the featured combination of images from Hubble and several ground based telescopes are sprawling spiral arms delineated by open clusters of bright blue stars, lanes of dark dust, the diffuse glow of billions of faint stars, and a short bar across the galaxy center. What intrigues many astronomers, however, is the circumnuclear ring around the galaxy center visible just outside the central bar. Although the long term stability of this ring remains a topic of research, observations indicate its present brightness is at least enhanced by transient bursts of star formation. M95, also known as NGC 3351, spans about 50,000 light-years, lies about 30 million light years away, and can be seen with a small telescope toward the constellation of the Lion (Leo).
Star formation can be colorful. This chromatic cosmic portrait features glowing gas and dark dust near some recently formed stars of NGC 3572, a little-studied star cluster near the Carina Nebula. Stars from NGC 3572 are visible near the bottom of the image, while the expansive gas cloud above is likely what remains of their formation nebula. The image‘s striking hues were created by featuring specific colors emitted by hydrogen, oxygen, and sulfur, and blending them with images recorded through broadband filters in red, green, and blue. This nebula near NGC 3572 spans about 100 light years and lies about 9,000 light years away toward the southern constellation of the Ship’s Keel (Carina). Within a few million years the pictured gas will likely disperse, while gravitational encounters will likely disperse the cluster stars over about a billion years.
Sometimes it’s hard to decide which is more impressive — the land or the sky. On the land of the featured image, for example, the Volcano of Fire (Volcán de Fuego) is seen erupting topped by red-hot, wind-blown ash and with streams of glowing lava running down its side. Lights from neighboring towns are seen through a thin haze below. In the sky, though, the central plane of our Milky Way Galaxy runs diagonally from the upper left, with a fleeting meteor just below, and the trail of a satellite to the upper right. The planet Jupiter also appears toward the upper left, with the bright star Antares just to its right. Much of the land and the sky were captured together in a single, well-timed, 25-second exposure taken in mid-April from the side of Fuego‘s sister volcano Acatenango in Guatemala. The image of the meteor, though, was captured in a similar frame taken about 30 minutes earlier — when the volanic eruption was not as photogenic — and added later digitally.
One of the most spectacular solar sights is an erupting prominence. In 2011, NASA’s Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressively large prominence erupting from the surface. The dramatic explosion was captured in ultraviolet light in the featured time lapse video covering 90 minutes, where a new frame was taken every 24 seconds. The scale of the prominence is huge — the entire Earth would easily fit under the flowing curtain of hot gas. A solar prominence is channeled and sometimes held above the Sun’s surface by the Sun’s magnetic field. A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. The energy mechanism that creates a solar prominence is still a topic of research. After our Sun passes the current Solar Minimum, solar activity like eruptive prominences are expected to become more common over the next few years.
What bizarre planet are these alien creatures from? It’s only planet Earth, of course. The planet’s home galaxy the Milky Way stretches across a dark sky in the panoramic, fisheye all-sky projection composed with a wide lens. But the imposing forms gazing skyward probably look strange to many denizens of Earth. Found on the Canary Island of Tenerife in the Teide National Park, they are red tajinastes, flowering plants that grow to a height of up to 3 meters. Among the rocks of the volcanic terrain, tajinastes bloom in spring and early summer and then die after a week or so as their seeds mature. A species known as Echium wildpretii, the terrestrial life forms were individually lit by flashlight during the wide-angle exposures.
An abundance of boulders litters the surface asteroid 101955 Bennu in this dramatic close-up from the OSIRIS-REx spacecraft. Taken on March 28 from a distance of just 3.4 kilometers (2.1 miles) the field of view is about 50 meters across while the light colored boulder at top right is 4.8 meters tall. Likely a loose conglomerate rubble pile asteroid, Bennu itself spans less than 500 meters. That’s about the height of the Empire State Building. Mapping the near Earth asteroid since the spacecraft’s arrival in December of 2018, the OSIRIS-REx mission plans a TAG (Touch-and-Go) maneuver for July 2020 to sample Bennu’s rugged surface, returning the sample to planet Earth in September 2023. Citizen scientists have been invited to help choose the sample collection site.
On May 20, a nearly Full Moon and Jupiter shared this telephoto field of view. Captured when a passing cloud bank dimmed the moonlight, the single exposure reveals the familiar face of our fair planet’s own large natural satellite, along with bright Jupiter (lower right) and some of its Galilean moons. Lined up left to right the tiny pinpricks of light near Jupiter are Ganymede, Europa, [Jupiter] and Callisto. (That’s not just dust on your screen …) Closer and brighter, our own natural satellite appears to loom large. But Ganymede, and Callisto are physically larger than Earth’s Moon, while water world Europa is only slightly smaller. In fact, of the Solar System’s six largest planetary satellites, Saturn’s moon Titan is missing from the scene and a fourth Galilean moon, Io, is hidden by our ruling gas giant.
How does your favorite planet spin? Does it spin rapidly around a nearly vertical axis, or horizontally, or backwards? The featured video animates NASA images of all eight planets in our Solar System to show them spinning side-by-side for an easy comparison. In the time-lapse video, a day on Earth — one Earth rotation — takes just a few seconds. Jupiter rotates the fastest, while Venus spins not only the slowest (can you see it?), but backwards. The inner rocky planets, across the top, most certainly underwent dramatic spin-altering collisions during the early days of the Solar System. The reasons why planets spin and tilt as they do remains a topic of research with much insight gained from modern computer modeling and the recent discovery and analysis of hundreds of exoplanets: planets orbiting other stars.
Atlas, Daphnis, and Pan are small, inner, ring moons of Saturn. They are shown at the same scale in this montage of images by the Cassini spacecraft that made its grand final orbit of the ringed planet in September 2017. In fact, Daphnis was discovered in Cassini images from 2005. Atlas and Pan were first sighted in images from the Voyager 1 and 2 spacecraft. Flying saucer-shaped Atlas orbits near the outer edge of Saturn’s bright A Ring while Daphnis orbits inside the A Ring’s narrow Keeler Gap and Pan within the A Ring’s larger Encke Gap. The curious equatorial ridges of the small ring moons could be built up by the accumulation of ring material over time. Even diminutive Daphnis makes waves in the ring material as it glides along the edge of the Keeler Gap.