Meeting in the Mesosphere

A sensitive video camera on a summit of the Vosges mountains in France captured these surprising fireworks above a distant horizon on June 26. Generated over intense thunderstorms, this one about 260 kilometers away, the brief and mysterious flashes have come to be known as red sprites. The transient luminous events are caused by electrical breakdown at altitudes of 50 to 100 kilometers. That puts them in the mesophere, the coldest layer of planet Earth’s atmosphere. The glow beneath the sprites is from more familiar lighting though, below the storm clouds. But on the right, the video frames have captured another summertime apparition from the mesophere. The silvery veins of light are polar mesospheric clouds. Also known as noctilucent or night shining clouds, the icy clouds still reflect the sunlight when the Sun is below the horizon. [via NASA]

Lynds Dark Nebula 1251

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, buried behind the dusty expanse. This alluring view imaged with a backyard telescope and broadband filters spans about two full moons on the sky, or 17 light-years at the estimated distance of LDN 1251. [via NASA]

The Galaxy, the Planet, and the Apple Tree

The Old Astronomer’s Milky Way arcs through this peaceful northern sky. Against faint, diffuse starlight you can follow dark rifts of interstellar dust clouds stretching from the galaxy’s core. They lead toward bright star Antares at the right, almost due south above the horizon. The brightest beacon in the twilight is Jupiter, though. From the camera’s perspective it seems to hang from the limb of a tree framing the foreground, an apple tree of course. The serene maritime nightscape was recorded in tracked and untracked exposures on June 16 from Dover, Nova Scotia, planet Earth. [via NASA]

Our Rotating Earth

Has your world ever turned upside-down? It would happen every day if you stay fixed to the stars. Most time-lapse videos of the night sky show the stars and sky moving above a steady Earth. Here, however, the camera has been forced to rotate so that the stars remain fixed, and the Earth rotates around them. The movie, with each hour is compressed to a second, dramatically demonstrates the daily rotation of the Earth, called diurnal motion. The video begins by showing an open field in Namibia, Africa, on a clear day, last year. Shadows shift as the Earth turns, the shadow of the Earth rises into the sky, the Belt of Venus momentarily appears, and then day turns into night. The majestic band of our Milky Way Galaxy stretches across the night sky, while sunlight-reflecting, Earth-orbiting satellites zoom by. In the night sky, you can even spot the Large and Small Magellanic Clouds. The video shows a sky visible from Earth’s Southern Hemisphere, but a similar video could be made for every middle latitude on our blue planet. [via NASA]

Bright Planetary Nebula NGC 7027 from Hubble

What created this unusual planetary nebula? NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as visible from Earth, about 600 years ago. For much of its history, the planetary nebula has been expelling shells, as seen in blue in the featured image. In modern times, though, for reasons unknown, it began ejecting gas and dust (seen in red) in specific directions that created a new pattern that seems to have four corners. These shells and patterns have been mapped in impressive detail by recent images from the Wide Field Camera 3 onboard the Hubble Space Telescope. What lies at the nebula’s center is unknown, with one hypothesis holding it to be a close binary star system where one star sheds gas onto an erratic disk orbiting the other star. NGC 7027, about 3,000 light years away, was first discovered in 1878 and can be seen with a standard backyard telescope toward the constellation of the Swan (Cygnus). [via NASA]

Dark Sky Reflections

When the lake calmed down, many wonders of the land and sky appeared twice. Perhaps the most dramatic from the dark sky was the central band of our Milky Way Galaxy, visible as a diagonal band. Toward the right were both the Small (SMC) and Large (LMC) Magellanic Clouds, satellite galaxies of our Milky Way. Faint multicolored bands of airglow fanned across the night. Numerous bright stars were visible including Antares, while the bright planet Jupiter appears just above the image center. The featured image is a composite of exposures all taken from the same camera and from the same location within 30 minutes in mid-May from the shore of Lake Bonney Riverland in South Australia. Dead trees that extend from the lake were captured not only in silhouette, but reflection, while lights from the small town of Barmera were visible across the lake. In July, Jupiter and Saturn will rise toward the east just as the Sun sets in the west. [via NASA]

Europa and Jupiter from Voyager 1

What are those spots on Jupiter? Largest and furthest, just right of center, is the Great Red Spot — a huge storm system that has been raging on Jupiter possibly since Giovanni Cassini’s likely notation of it 355 years ago. It is not yet known why this Great Spot is red. The spot toward the lower left is one of Jupiter’s largest moons: Europa. Images from Voyager in 1979 bolster the modern hypothesis that Europa has an underground ocean and is therefore a good place to look for extraterrestrial life. But what about the dark spot on the upper right? That is a shadow of another of Jupiter’s large moons: Io. Voyager 1 discovered Io to be so volcanic that no impact craters could be found. Sixteen frames from Voyager 1’s flyby of Jupiter in 1979 were recently reprocessed and merged to create the featured image. About 43 years ago, Voyager 1 launched from Earth and started one of the greatest explorations of the Solar System ever. [via NASA]

Eclipse under the ISS

The dark shadow of the New Moon reached out and touched planet Earth on June 21. A high definition camera outside the International Space Station captured its passing in this snapshot from low Earth orbit near the border of Kazakhstan and China. Of course those along the Moon’s central shadow track below could watch the much anticipated annular eclipse of the Sun. In the foreground a cargo spacecraft is docked with the orbital outpost. It’s the H-II Transfer Vehicle-9 from JAXA the Japan Aerospace Exploration Agency. [via NASA]

Eclipse under the Bamboo

Want to watch a solar eclipse safely? Try looking down instead of up, though you might discover you have a plethora of images to choose from. For example, during the June 21st solar eclipse this confusing display appeared under a shady bamboo grove in Pune, India. Small gaps between close knit leaves on the tall plants effectively created a network of randomly placed pinholes. Each one projected a separate image of the eclipsed Sun. The snapshot was taken close to the time of maximum eclipse in Pune when the Moon covered about 60 percent of the Sun’s diameter. But an annular eclipse, the Moon in silhouette completely surrounded by a bright solar disk at maximum, could be seen along a narrow path where the Moon’s dark shadow crossed central Africa, south Asia, and China. [via NASA]

Eclipse Street, Hong Kong

On June 21 an annular solar eclipse came soon after the solstice and our fair planet’s northernmost sunset for 2020. At maximum eclipse, the New Moon in silhouette created a ring of fire visible along a narrow path at most 85 kilometers wide. The annular eclipse path began in central Africa, crossed south Asia and China, and ended over the Pacific Ocean. But a partial eclipse of the Sun was visible over a much broader region. In Hong Kong, this busy section of Jordan Street looks to the northwest, well-aligned with the track of the near solstice afternoon Sun. The street level view was composited with an eclipse sequence made with a safe solar filter on the camera. For that location the eclipse was partial. The Moon covered about 90 percent of the Sun’s diameter at maximum, seen near the middle of the eclipse sequence. [via NASA]