Star Colors and Pinyon Pine


Beautiful, luminous decorations on this pinyon pine tree are actually bright stars in the constellation Scorpius and the faint glow of the central Milky Way. Captured in June from the north rim of the Grand Canyon of planet Earth, the shallow, close focus image has rendered pine needles on the tree branch sharp, but blurred the distant stars, their light smeared into remarkably colorful disks. Of course, temperature determines the color of a star. Most of the out-of-focus bright stars of Scorpius show a predominately blue hue, their surface temperatures much hotter than the Sun’s. Cooler and larger than the Sun, and noticably redder on the scene, is giant star Antares at the heart of the scorpion. In focused, telescopic views the whitish disk at the upper right would be immediately recognizable though, reflecting the Sun’s light as ringed gas giant Saturn.

from NASA http://ift.tt/1OpIO30
via IFTTT

Geminid Meteors over Xinglong Observatory


Where do Geminid meteors come from? In terms of location on the sky, as the featured image composite beautifully demonstrates, the sand-sized bits of rock that create the streaks of the Geminid Meteor Shower appear to flow out from the constellation of Gemini. In terms of parent body, Solar System trajectories point to the asteroid 3200 Phaethon — but this results in a bit of a mystery since that unusual object appears mostly dormant. Perhaps, 3200 Phaethon undergoes greater dust-liberating events than we know, but even if so, exactly what happens and why remains a riddle. Peaking last week, over 50 meteors including a bright fireball were captured streaking above Xinglong Observatory in China. Since the Geminids of December are one of the most predictable and active meteor showers, investigations into details of its origin are likely to continue.

from NASA http://ift.tt/1RGdL3e
via IFTTT

SN Refsdal: The First Predicted Supernova Image


It’s back. Never before has an observed supernova been predicted. The unique astronomical event occurred in the field of galaxy cluster MACS J1149.5+2223. Most bright spots in the featured image are galaxies in this cluster. The actual supernova, dubbed Supernova Refsdal, occurred just once far across the universe and well behind this massive galaxy cluster. Gravity caused the cluster to act as a massive gravitational lens, splitting the image of Supernova Refsdal into multiple bright images. One of these images arrived at Earth about ten years ago, likely in the upper red circle, and was missed. Four more bright images peaked in April in the lowest red circle, spread around a massive galaxy in the cluster as the first Einstein Cross supernova. But there was more. Analyses revealed that a sixth bright supernova image was likely still on its way to Earth and likely to arrive within the next year. Earlier this month — right on schedule — this sixth bright image was recovered, in the middle red circle, as predicted. Studying image sequences like this help humanity to understand how matter is distributed in galaxies and clusters, how fast the universe expands, and how massive stars explode.

from NASA http://ift.tt/1NItoRO
via IFTTT

A Dark Earth with a Red Sprite


There is something very unusual in this picture of the Earth — can you find it? A fleeting phenomenon once thought to be only a legend has been newly caught if you know just where to look. The featured image was taken from the orbiting International Space Station (ISS) in late April and shows familiar ISS solar panels on the far left and part of a robotic arm to the far right. The rarely imaged phenomenon is known as a red sprite and it can be seen, albeit faintly, just over the bright area on the image right. This bright area and the red sprite are different types of lightning, with the white flash the more typical type. Although sprites have been reported anecdotally for as long as 300 years, they were first caught on film in 1989 — by accident. Much remains unknown about sprites including how they occur, their effect on the atmospheric global electric circuit, and if they are somehow related to other upper atmospheric lightning phenomena such as blue jets or terrestrial gamma flashes.

from NASA http://ift.tt/1JlE0Eh
via IFTTT

Star Streams and the Whale Galaxy


NGC 4631 is a spiral galaxy found only 25 million light-years away, toward the well-trained northern constellation Canes Venatici. Seen ege-on, the galaxy is similar in size to the Milky Way. Its distorted wedge shape suggests to some a cosmic herring and to others its popular moniker, The Whale Galaxy. The large galaxy’s small, remarkably bright elliptical companion NGC 4627 lies just above its dusty yellowish core, but also identifiable are recently discovered, faint dwarf galaxies within the halo of NGC 4631. In fact, the faint extended features below (and above) NGC 4631 are now recognized as tidal star streams. The star streams are remnants of a dwarf satellite galaxy disrupted by repeated encounters with the Whale that began about 3.5 billion years ago. Even in nearby galaxies, the presence of tidal star streams is predicted by cosmological models of galaxy formation, including the formation of our own Milky Way.

from NASA http://ift.tt/1YnMMh7
via IFTTT

Herbig Haro 24


This might look like a double-bladed lightsaber, but these two cosmic jets actually beam outward from a newborn star in a galaxy near you. Constructed from Hubble Space Telescope image data, the stunning scene spans about half a light-year across Herbig-Haro 24 (HH 24), some 1,300 light-years or 400 parsecs away in the stellar nurseries of the Orion B molecular cloud complex. Hidden from direct view, HH 24’s central protostar is surrounded by cold dust and gas flattened into a rotating accretion disk. As material from the disk falls toward the young stellar object it heats up. Opposing jets are blasted out along the system’s rotation axis. Cutting through the region’s interstellar matter, the narrow, energetic jets produce a series of glowing shock fronts along their path.

from NASA http://ift.tt/1k6olSs
via IFTTT

Geminids of the South


Earth’s annual Geminid meteor shower did not disappoint, peaking before dawn on December 14 as our fair planet plowed through dust from active asteroid 3200 Phaethon. Captured in this southern hemisphere nightscape the meteors stream away from the shower’s radiant in Gemini. To create the image, many individual frames recording meteor streaks were taken over period of 5 hours. In the final composite they were selected and registered against the starry sky above the twin 6.5 meter Magellan telescopes of Carnegie Las Campanas Observatory in Chile. Rigel in Orion, and Sirius shine brightly as the Milky Way stretches toward the zenith. Near Castor and Pollux the twin stars of Gemini, the meteor shower’s radiant is low, close to the horizon. The radiant effect is due to perspective as the parallel meteor tracks appear to converge in the distance. Gemini’s meteors enter Earth’s atmosphere traveling at about 22 kilometers per second.

from NASA http://ift.tt/22acbu1
via IFTTT

The Horsehead Nebula


The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula in the center of the above photograph. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright red emission nebula. Like clouds in Earth’s atmosphere, this cosmic cloud has assumed a recognizable shape by chance. After many thousands of years, the internal motions of the cloud will surely alter its appearance. The emission nebula‘s red color is caused by electrons recombining with protons to form hydrogen atoms. On the image left is the Flame Nebula, an orange-tinged nebula that also contains filaments of dark dust. Just to the lower left of the Horsehead nebula featured picture is a blueish reflection nebulae that preferentially reflects the blue light from nearby stars.

from NASA http://ift.tt/1lPuhBd
via IFTTT

Colorful Arcs over Buenos Aires


What are those colorful arcs in the sky? Like rainbows that are caused by rain, arcs of sunlight broken up into component colors can also result when ice crystals floating in Earth’s atmosphere act together as a gigantic prism. The top color arc is more typical as it is part of the 22 degree halo surrounding the Sun when hexagonal ice crystals refract sunlight between two of the six sides. More unusual, though, is the bottom color arc. Sometimes called a fire rainbow, this circumhorizon arc is also created by ice, not fire nor even rain. Here, a series of horizontal, thin, flat ice crystals in high cirrus clouds refract sunlight between the top and bottom faces toward the observer. These arcs only occur when the Sun is higher than 58 degrees above the horizon. The featured sky occurred to the northwest in the early afternoon last month over a street Diagonal of La Plata City, Buenos Aires, Argentina.

from NASA http://ift.tt/1J92mRy
via IFTTT

Pluto: From Mountains to Plains


What do the sharpest views ever of Pluto show? As the robotic New Horizons spacecraft moves into the outer Solar System, it is now sending back some of the highest resolution images from its historic encounter with Pluto in July. Featured here is one recently-received, high-resolution image. On the left is al-Idrisi Montes, mountainous highlands thought composed primarily of blocks of water ice. A sharp transitional shoreline leads to the ice plains, on the right, that compose part of the heart-shaped feature known as Sputnik Planum, which contains ices including solid nitrogen. Why the plains are textured with ice pits and segmented is currently unknown. The image was taken about 15 minutes before closest approach and shows an area about 30 kilometers across. The New Horizons spacecraft is next scheduled to fly past Kuiper Belt object 2014 MU 69 on New Year’s Day 2019.

from NASA http://ift.tt/1I3Z5b6
via IFTTT