Sam's Astrophtography Thread

[Seven]

Prometheus and the F Ring
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: In Greek myth Prometheus was a Titan, known for bringing fire from Mount Olympus. But in modern times the name is given to a small moon of Saturn, orbiting just inside Saturn's F ring. In a complex interaction, the tiny potato-shaped moon interacts with the icy ring particles creating structures along the F ring still not fully understood. One of the highest resolution views of Prometheus, this image of its pocked surface posing with the thin F ring in the background was taken during the Cassini spacecraft's close approach on December 6, 2015. Elongated Prometheus is roughly 150 kilometers (90 miles) long by 70 kilometers wide.

Is this a "Chunk' of something or was this once round, like other planets, and just eroded away?

Did I ask that right?

 

[YosemiteSam]

Is this a "Chunk' of something or was this once round, like other planets, and just eroded away?

Did I ask that right?

That is a large asteroid that was captured by Saturn that now functions as a Moon of Saturn. (it was discovered in Oct. 1980 when Voyager I passed by it) Once an object like that reaches critical mass (if it is still collecting mass from space), it will crush itself into a sphere. (that's how planet's end up round) Prometheus (this moon) isn't quite large enough to do that.

 

[Seven]

That is a large asteroid that was captured by Saturn that now functions as a Moon of Saturn. (it was discovered in Oct. 1980 when Voyager I passed by it) Once an object like that reaches critical mass (if it is still collecting mass from space), it will crush itself into a sphere. (that's how planet's end up round) Prometheus (this moon) isn't quite large enough to do that.

Exactly the opposite of what I was thinking.............thanks, Sam.

Amazing stuff.

 

[YosemiteSam]

Star Streams and the Whale Galaxy
Image Credit & Copyright: R Jay Gabany (Blackbird Observatory)
Collaboration: David Martínez-Delgado (University of Heidelberg), et al.

Explanation: NGC 4631 is a spiral galaxy found only 25 million light-years away, toward the well-trained northern constellation Canes Venatici. Seen egde-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.

 

[YosemiteSam]

Puppis A Supernova Remnant
Image Credit & Copyright: Don Goldman

Explanation: Driven by the explosion of a massive star, supernova remnant Puppis A is blasting into the surrounding interstellar medium about 7,000 light-years away. At that distance, this colorful telescopic field based on broadband and narrowband optical image data is about 60 light-years across. As the supernova remnant expands into its clumpy, non-uniform surroundings, shocked filaments of oxygen atoms glow in green-blue hues. Hydrogen and nitrogen are in red. Light from the initial supernova itself, triggered by the collapse of the massive star's core, would have reached Earth about 3,700 years ago. The Puppis A remnant is actually seen through outlying emission from the closer but more ancient Vela supernova remnant, near the crowded plane of our Milky Way galaxy. Still glowing across the electromagnetic spectrum Puppis A remains one of the brightest sources in the X-ray sky.

 

[YosemiteSam]

An Unusual Mountain on Asteroid Ceres
Image Credit: NASA, JPL-Caltech, UCLA, MPS/DLR/IDA

Explanation: What created this large mountain on asteroid Ceres? No one is yet sure. As if in anticipation of today being Asteroid Day on Earth, (this is an old post, it's not Asteroid day today hah) the robotic spacecraft Dawn in orbit around Ceres took the best yet image of an unusually tall mountain on the Asteroid Belt's largest asteroid. Visible at the top of the featured image, the exceptional mountain rises about five kilometers up from an area that otherwise appears pretty level. The image was taken about two weeks ago from about 4,400 kilometers away. Although origin hypotheses for the mountain include volcanism, impacts, and plate tectonics, clear evidence backing any of these is currently lacking. Also visible across Ceres' surface are some enigmatic light areas: bright spots whose origin and composition that also remain an active topic of investigation. Even though Dawn is expected to continue to orbit Ceres, officially dubbed a dwarf planet, for millions of years, the hydrazine fuel used to point Dawn's communications antenna toward Earth is expected to run out sometime next year.

 

[YosemiteSam]

Ring Galaxy AM 0644-741 from Hubble
Image Credit: Hubble Heritage Team (AURA / STScI), J. Higdon (Cornell) ESA, NASA

Explanation: How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. That galaxy, AM 0644-741, is known as a ring galaxy and was caused by an immense galaxy collision. When galaxies collide, they pass through each other -- their individual stars rarely come into contact. The ring-like shape is the result of the gravitational disruption caused by an entire small intruder galaxy passing through a large one. When this happens, interstellar gas and dust become condensed, causing a wave of star formation to move out from the impact point like a ripple across the surface of a pond. The intruder galaxy is just outside of the frame taken by the Hubble Space Telescope. This featured image was taken to commemorate the anniversary of Hubble's launch in 1990. Ring galaxy AM 0644-741 lies about 300 million light years away.

 

[YosemiteSam]

The Surface of Europa
Image Credit: NASA, JPL-Caltech, SETI Institute

Explanation: An enhanced-color view, this image covers a 350 by 750 kilometer swath across the surface of Jupiter's tantalizing moon Europa. The close-up combines high-resolution image data with lower resolution color data from observations made in 1998 by the Galileo spacecraft. Smooth ice plains, long fractures, and jumbled blocks of chaos terrain are thought to hide a deep ocean of salty liquid water beneath. Though the ice-covered alien ocean world is outside the Solar System's habitable zone, new studies show the potential chemistry driving its oxygen and hydrogen production, a key indicator of the energy available for life, could produce amounts comparable in scale to planet Earth. Hydrogen would be generated by chemical reactions of the salty water in contact with the rocky ocean floor. Oxygen and other compounds that react with hydrogen would come from Europa's surface. There water ice molecules would be split apart by the intense flux of high-energy radiation from Jupiter and cycled into the Europan ocean from above.

 

[YosemiteSam]

The Shark Nebula
Image Credit & Copyright: Maurice Toet

Explanation: There is no sea on Earth large enough to contain the Shark nebula. This predator apparition poses us no danger, though, as it is composed only of interstellar gas and dust. Dark dust like that featured here is somewhat like cigarette smoke and created in the cool atmospheres of giant stars. After being expelled with gas and gravitationally recondensing, massive stars may carve intricate structures into their birth cloud using their high energy light and fast stellar winds as sculpting tools. The heat they generate evaporates the murky molecular cloud as well as causing ambient hydrogen gas to disperse and glow red. During disintegration, we humans can enjoy imagining these great clouds as common icons, like we do for water clouds on Earth. Including smaller dust nebulae such as Lynds Dark Nebula 1235 and Van den Bergh 149 & 150, the Shark nebula spans about 15 light years and lies about 650 light years away toward the constellation of the King of Aethiopia (Cepheus).

A couple of points of Interest highlighted.

 

[YosemiteSam]

Saturn, Tethys, Rings, and Shadows
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: Seen from ice moon Tethys, rings and shadows would display fantastic views of the Saturnian system. Haven't dropped in on Tethys lately? Then this gorgeous ringscape from the Cassini spacecraft will have to do for now. Caught in sunlight just below and left of picture center in 2005, Tethys itself is about 1,000 kilometers in diameter and orbits not quite five saturn-radii from the center of the gas giant planet. At that distance (around 300,000 kilometers) it is well outside Saturn's main bright rings, but Tethys is still one of five major moons that find themselves within the boundaries of the faint and tenuous outer E ring. Discovered in the 1980s, two very small moons Telesto and Calypso are locked in stable locations along Tethys' orbit. Telesto precedes and Calypso follows Tethys as the trio circles Saturn.

 

[YosemiteSam]

IC 5067 in the Pelican Nebula
Image Credit & Copyright: Data - Subaru Telescope (NAOJ), R. Colombari, Processing - Roberto Colombari

Explanation: The prominent ridge of emission featured in this sharp, colorful skyscape is cataloged as IC 5067. Part of a larger emission nebula with a distinctive shape, popularly called The Pelican Nebula, the ridge spans about 10 light-years following the curve of the cosmic pelican's head and neck. This false-color view also translates the pervasive glow of narrow emission lines from atoms in the nebula to a color palette made popular in Hubble Space Telescope images of star forming regions. Fantastic, dark shapes inhabiting the 1/2 degree wide field are clouds of cool gas and dust sculpted by the winds and radiation from hot, massive stars. Close-ups of some of the sculpted clouds show clear signs of newly forming stars. The Pelican Nebula, itself cataloged as IC 5070, is about 2,000 light-years away. To find it, look northeast of bright star Deneb in the high flying constellation Cygnus.

 

[YosemiteSam]

The Great Carina Nebula
Image Credit & Copyright: Peter Ward (Barden Ridge Observatory)

Explanation: A jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, spans over 300 light-years, one of our galaxy's largest star forming regions. Like the smaller, more northerly Great Orion Nebula, the Carina Nebula is easily visible to the unaided eye, though at a distance of 7,500 light-years it is some 5 times farther away. This gorgeous telescopic close-up reveals remarkable details of the region's central glowing filaments of interstellar gas and obscuring cosmic dust clouds. The field of view is over 50 light-years across. The Carina Nebula is home to young, extremely massive stars, including the stars of open cluster Trumpler 14 (below and right of center) and the still enigmatic variable Eta Carinae, a star with well over 100 times the mass of the Sun. Eta Carinae is the brightest star, seen here just above the dusty Keyhole Nebula (NGC 3324). While Eta Carinae itself maybe on the verge of a supernova explosion, X-ray images indicate that the Great Carina Nebula has been a veritable supernova factory.

 

[YosemiteSam]

Two Hours Before Neptune
Image Credit: Voyager 2, NASA

Explanation: Two hours before closest approach to Neptune in 1989, the Voyager 2 robot spacecraft snapped this picture. Clearly visible for the first time were long light-colored cirrus-type clouds floating high in Neptune's atmosphere. Shadows of these clouds can even be seen on lower cloud decks. Most of Neptune's atmosphere is made of hydrogen and helium, which is invisible. Neptune's blue color therefore comes from smaller amounts of atmospheric methane, which preferentially absorbs red light. Neptune has the fastest winds in the Solar System, with gusts reaching 2000 kilometers per hour. (almost 1,300mph) Speculation holds that diamonds may be created in the dense hot conditions that exist under the cloud tops of Uranus and Neptune. Twenty-six years later, NASA's to zoom past Pluto this July.

 

[YosemiteSam]

Valles Marineris: The Grand Canyon of Mars
Image Credit: Viking Project, USGS, NASA

Explanation: Mars will look good in Earth's skies over the next few days -- but not this good. To get a view this amazing, a spacecraft had to actually visit the red planet. Running across the image center, though, is one the largest canyons in the Solar System. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Several geologic processes have been identified in the canyon. The featured mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s. Tomorrow, Mars and Earth will pass the closest in 11 years, resulting in the red planet being quite noticeable toward the southeast after sunset.

 

[panchucko]

Valles Marineris: The Grand Canyon of Mars
Image Credit: Viking Project, USGS, NASA

Explanation: Mars will look good in Earth's skies over the next few days -- but not this good. To get a view this amazing, a spacecraft had to actually visit the red planet. Running across the image center, though, is one the largest canyons in the Solar System. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Several geologic processes have been identified in the canyon. The featured mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s. Tomorrow, Mars and Earth will pass the closest in 11 years, resulting in the red planet being quite noticeable toward the southeast after sunset.

What are those spots on the left, storms or impact craters. They would be some big ole craters

 

[YosemiteSam]

What are those spots on the left, storms or impact craters. They would be some big ole craters

Yep, impact craters. Mars' atmohphere is about 100 times thinner than the Earths and of course, Mars doesn't have weather as strong as ours which could smoothen out or completely wash away large craters. Therefore, you can clearly see remnants of Mars' violent past!

EDIT: If you look below the second one, there is a much older and wide spread third one!

BOOM!

 

[YosemiteSam]

Stars and Gas of the Running Chicken Nebula
Image Credit & Copyright: Andrew Campbell

Explanation: To some, it looks like a giant chicken running across the sky. To others, it looks like a gaseous nebula where star formation takes place. Cataloged as IC 2944, the Running Chicken Nebula spans about 100 light years and lies about 6,000 light years away toward the constellation of the Centaur (Centaurus). The featured image, shown in scientifically assigned colors, was captured recently in an 11-hour exposure from a backyard near Melbourne, Australia. Two star clusters are visible: the Pearl Cluster seen on the far left, and Collinder 249 embedded in the nebula's glowing gas. Although difficult to discern here, several dark molecular clouds with distinct shapes can be found inside the nebula.

 

[YosemiteSam]

The Shadow of Surveyor 1
Image Credit: NASA / GSFC / Arizona State U. / Lunar Reconnaissance Orbiter

Explanation: Fifty years ago, Surveyor 1 reached the Moon. Launched on May 30, 1966 and landed on June 2, 1966 with the Moon at full phase it became the first US spacecraft to make a soft landing on another world. The first of seven Surveyor missions intended to test the lunar terrain for the planned Apollo landings it sent back over 10,000 images before lunar nightfall on June 14. The total rose to over 11,000 images returned before its second lunar night began on July 13.Surveyor 1 continued to respond from the lunar surface until January 7, 1967. Captured in this 2009 image from the Lunar Reconnaissance Orbiter, the first Surveyor still stands at its landing site, a speck in the Oceanus Procellarum (the Ocean of Storms). With the Sun low on the western horizon the lonely, 3.3 meter tall spacecraft casts a shadow almost 15 meters long in the late lunar afternoon.

 

[YosemiteSam]

Comet PanSTARRS and the Helix Nebula
Image Credit & Copyright: Fritz Helmut Hemmerich

Explanation: It's rare that such different objects are imaged so close together. Such an occasion is occurring now, though, and was captured two days ago in combined parallel exposures from the Canary Islands of Spain. On the lower right, surrounded by a green coma and emanating an unusually split blue ion tail diagonally across the frame, is Comet C/2013 X1 (PanSTARRS). This giant snowball has been falling toward our Sun and brightening since its discovery in 2013. Although Comet PannSTARRS is a picturesque target for long-duration exposures of astrophotography, it is expected to be only barely visible to the unaided eye when it reaches its peak brightness in the next month. On the upper left, surrounded by red-glowing gas, is the also-picturesque Helix Nebula. At 700 light years distant, the Helix is not only much farther away than the comet, but is expected to retain its appearance for thousands of years.

 

[YosemiteSam]

The Horsehead Nebula in Infrared from Hubble
Image Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

Explanation: 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 above gorgeously detailed image was taken in 2013 in infrared light by the orbiting Hubble Space Telescope in honor of the 23rd anniversary of Hubble's launch. 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 the high energy starlight.