While drifting through the cosmos, a magnificent interstellar dust cloud became sculpted by stellar winds and radiation to assume a recognizable shape. Fittingly named the Horsehead Nebula, it is embedded in the vast and complex Orion Nebula (M42). A potentially rewarding but difficult object to view personally with a small telescope, the featured gorgeously detailed image was taken in infrared light by the orbiting Hubble Space Telescope. The dark molecular cloud, roughly 1,500 light years distant, is cataloged as Barnard 33 and is seen above primarily because it is backlit by the nearby massive star Sigma Orionis. The Horsehead Nebula will slowly shift its apparent shape over the next few million years and will eventually be destroyed by high energy starlight.
What’s happening in the Statue of Liberty nebula? Bright stars and interesting molecules are forming and being liberated. The complex nebula resides in the star forming region called RCW 57, and besides the iconic monument, to some looks like a flying superhero or a weeping angel. By digitally removing the stars, this re-assigned color image showcases dense knots of dark interstellar dust, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A detailed study of NGC 3576, also known as NGC 3582 and NGC 3584, uncovered at least 33 massive stars in the end stages of formation, and the clear presence of the complex carbon molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs are thought to be created in the cooling gas of star forming regions, and their development in the Sun’s formation nebula five billion years ago may have been an important step in the development of life on Earth.
The beauty in this image comes in layers. On the bottom layer is the picturesque village of Manlleu in Barcelona, Spain. The six-minute exposure makes car lights into streaks. The next layer is a mountain — Serra de Bellmunt — of Europe’s famous Pyrenees. Next up is a tremendous lightning storm emanating from a classically-shaped anvil cloud. The long exposure allowed for the capture of many intricate lightning bolts. Finally, at the top and furthest in the distance are stars. Here, the multi-minute exposure made stars into trails. The trailing effect is caused by the rotation of the Earth, and the curvature of the trails indicates their distance from the north spin pole of the Earth above. Taken after sunset in early June, the lightning storm soon moved off. The stars, though, will continue to circle the poll for as long as the Earth spins — surely billions of years into the future.
If you went outside at the same time every day and took a picture that included the Sun, how would the Sun’s position change? A more visual answer to that question is an analemma, a composite image taken from the same spot at the same time over the course of a year. The featured analemma was composed from images taken every few days at noon near the village of Callanish in the Outer Hebrides in Scotland, UK. In the foreground are the Callanish Stones, a stone circle built around 2700 BC during humanity’s Bronze Age. It is not known if the placement of the Callanish Stones has or had astronomical significance. The ultimate causes for the figure-8 shape of this and all analemmas are the tilt of the Earth axis and the ellipticity of the Earth’s orbit around the Sun. At the solstices, the Sun will appear at the top or bottom of an analemma. The featured image was taken near the December solstice and so the Sun appears near the bottom. Equinoxes, however, correspond to analemma middle points — not the intersection point. This coming Friday at 1:04 am (UT) — Thursday in the Americas — is the equinox (“equal night”), when day and night are equal over all of planet Earth. Many cultures celebrate a change of season at an equinox.
The Perseverance rover’s Mastcam-Z captured images to create this mosaic on August 4, 2022. The car-sized robot was continuing its exploration of the fan-shaped delta of a river that, billions of years ago, flowed into Jezero Crater on Mars. Sedimentary rocks preserved in Jezero’s delta are considered one of the best places on Mars to search for potential signs of ancient microbial life and sites recently sampled by the rover, dubbed Wildcat Ridge and Skinner Ridge, are at lower left and upper right in the frame. The samples taken from these areas were sealed inside ultra-clean sample tubes, ultimately intended for return to Earth by future missions. Starting with the Pathfinder Mission and Mars Global Surveyor in 1997, the last 25 years of a continuous robotic exploration of the Red Planet has included orbiters, landers, rovers, and a helicopter from planet Earth.
The Tarantula Nebula, also known as 30 Doradus, is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud. About 180 thousand light-years away, it’s the largest, most violent star forming region known in the whole Local Group of galaxies. The cosmic arachnid sprawls across this magnificent view, an assembly of image data from large space- and ground-based telescopes. Within the Tarantula (NGC 2070), intense radiation, stellar winds, and supernova shocks from the central young cluster of massive stars cataloged as R136 energize the nebular glow and shape the spidery filaments. Around the Tarantula are other star forming regions with young star clusters, filaments, and blown-out bubble-shaped clouds. In fact, the frame includes the site of the closest supernova in modern times, SN 1987A, at lower right. The rich field of view spans about 2 degrees or 4 full moons, in the southern constellation Dorado. But were the Tarantula Nebula closer, say 1,500 light-years distant like the Milky Way’s own star forming Orion Nebula, it would take up half the sky.
For northern hemisphere dwellers, September’s Full Moon was the Harvest Moon. Reflecting warm hues at sunset it rises over the historic town of Castiglione di Sicilia in this telephoto view from September 9. Famed in festival, story, and song Harvest Moon is just the traditional name of the full moon nearest the autumnal equinox. According to lore the name is a fitting one. Despite the diminishing daylight hours as the growing season drew to a close, farmers could harvest crops by the light of a full moon shining on from dusk to dawn.
It is one of the largest nebulas on the sky — why isn’t it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta). The emission nebula is difficult to see with wide-field binoculars because it is so faint, but also usually difficult to see with a large telescope because it is so great in angle — spanning about three degrees. The depth, breadth, waves, and beauty of the nebula — cataloged as Sharpless 126 (Sh2-126) — can best be seen and appreciated with a long duration camera exposure. The featured image is one such combined exposure — in this case 10 hours over five different colors and over six nights during this past June and July at the IC Astronomy Observatory in Spain. The hydrogen gas in the Great Lacerta Nebula glows red because it is excited by light from the bright star 10 Lacertae, one of the bright blue stars just above the red-glowing nebula’s center. The stars and nebula are about 1,200 light years distant.
Earlier this month, the Sun exhibited one of the longer filaments on record. Visible as the bright curving streak around the image center, the snaking filament’s full extent was estimated to be over half of the Sun‘s radius — more than 350,000 kilometers long. A filament is composed of hot gas held aloft by the Sun’s magnetic field, so that viewed from the side it would appear as a raised prominence. A different, smaller prominence is simultaneously visible at the Sun’s edge. The featured image is in false-color and color-inverted to highlight not only the filament but the Sun’s carpet chromosphere. The bright dot on the upper right is actually a dark sunspot about the size of the Earth. Solar filaments typically last from hours to days, eventually collapsing to return hot plasma back to the Sun. Sometimes, though, they explode and expel particles into the Solar System, some of which trigger auroras on Earth. The pictured filament appeared in early September and continued to hold steady for about a week.
What are those red filaments in the sky? They are a rarely seen form of lightning confirmed only about 35 years ago: red sprites. Research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light. They are quickly followed by a group of upward streaking ionized balls. The featured image was taken late last month from the Jeseniky Mountains in northern Moravia in the Czech Republic. The distance to the red sprites is about 200 kilometers. Red sprites take only a fraction of a second to occur and are best seen when powerful thunderstorms are visible from the side.