Astronomy Picture of the Day – LDN 988 and Friends

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 September 24

  LDN 988 and Friends
Image Credit & Copyright: Rafael Rodríguez Morales

 

 

Explanation: Stars are forming in dark, dusty molecular cloud LDN 988. Seen near picture center some 2,000 light-years distant, LDN 988 and other nearby dark nebulae were cataloged by Beverly T. Lynds in 1962 using Palomar Observatory Sky Survey plates. Narrowband and near-infrared explorations of the dark nebula reveal energetic shocks and outflows light-years across associated with dozens of newborn stars. But in this sharp optical telescopic view, the irregular outlines of LDN 988 and friends look like dancing stick figures eclipsing the rich starfields of the constellation Cygnus. From dark sites the region can be identified by eye alone. It’s part of the Great Rift of dark clouds along the plane of the Milky Way galaxy known as the Northern Coalsack.

Advertisements

Astronomy Picture of the Day – Pickering’s Triangle in the Veil

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 September 17

Pickering’s Triangle in the Veil
Image Credit & Copyright: J-P Metsävainio (Astro Anarchy)

 

Explanation: Chaotic in appearance, these filaments of shocked, glowing gas break across planet Earth’s sky toward the constellation of Cygnus, as part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star. Light from the original supernova explosion likely reached Earth over 5,000 years ago. Blasted out in the cataclysmic event, the interstellar shock waves plow through space sweeping up and exciting interstellar material. The glowing filaments are really more like long ripples in a sheet seen almost edge on, remarkably well separated into the glow of ionized hydrogen and sulfur atoms shown in red and green, and oxygen in blue hues. Also known as the Cygnus Loop, the Veil Nebula now spans nearly 3 degrees or about 6 times the diameter of the full Moon. While that translates to over 70 light-years at its estimated distance of 1,500 light-years, this field of view spans less than one third that distance. Identified as Pickering’s Triangle for a director of Harvard College Observatory and cataloged as NGC 6979, the complex of filaments might be more appropriately known as Williamina Fleming’s Triangular Wisp.

Astronomy Picture of the Day – Pluto from above Cthulhu Regio

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 September 14

Pluto from above Cthulhu Regio
Image Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Inst.

 

Explanation: New high resolution images of Pluto are starting to arrive from the outer Solar System. The robotic New Horizons spacecraft, which zoomed by Pluto in July, has finished sending back some needed engineering data and is now transmitting selections from its tremendous storehouse of images of Pluto and its moons. The featured image, a digital composite, details a surprising terrain filled with craters, plains, landscape of unknown character, and landforms that resemble something on Earth but are quite unexpected on Pluto. The light area sprawling across the upper right has been dubbed Sputnik Planum and is being studied for its unusual smoothness, while the dark cratered area just under the spacecraft is known as Cthulhu Regio. So far, New Horizons has only shared a few percent of the images and data it took during its Pluto flyby, but will continue to send back new views of the dwarf planet even as it glides outward toward even more distant explorations.

Astronomy Picture of the Day – Earthrise

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 September 6

Earthrise
Image Credit: Apollo 8, NASA

Explanation: What’s that rising over the edge of the Moon? Earth. About 47 years ago, in December of 1968, the Apollo 8 crew flew from the Earth to the Moon and back again. Frank Borman, James Lovell, and William Anders were launched atop a Saturn V rocket on December 21, circled the Moon ten times in their command module, and returned to Earth on December 27. The Apollo 8 mission’s impressive list of firsts includes: the first humans to journey to the Earth’s Moon, the first to fly using the Saturn V rocket, and the first to photograph the Earth from deep space. As the Apollo 8 command module rounded the farside of the Moon, the crew could look toward the lunar horizon and see the Earth appear to rise, due to their spacecraft’s orbital motion. Their famous picture of a distant blue Earth above the Moon’s limb was a marvelous gift to the world.

Astronomy Picture of the Day – Milky Way with Airglow Australis

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 September 4

Milky Way with Airglow Australis
Image Credit & Copyright: Yuri Beletsky (Carnegie Las Campanas Observatory)

 

Explanation: After sunset on September 1, an exceptionally intense, reddish airglow flooded this Chilean winter night skyscape. Above a sea of clouds and flanking the celestial Milky Way, the airglow seems to ripple and flow across the northern horizon in atmospheric waves. Originating at an altitude similar to aurorae, the luminous airglow is instead due to chemiluminescence, the production of light through chemical excitation. Commonly captured with a greenish tinge by sensitive digital cameras, this reddish airglow emission is from OH molecules and oxygen atoms at extremely low densities and has often been present in southern hemisphere nights during the last few years. On this night it was visible to the eye, but seen without color. Antares and the central Milky Way lie near the top, with bright star Arcturus at left. Straddling the Milky Way close to the horizon are Vega, Deneb, and Altair, known in northern nights as the stars of the Summer Triangle.

Astronomy Picture of the Day – The Flare and the Galaxy

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 September 2


The Flare and the Galaxy
Image Credit & Copyright: Martin Mark

 

Explanation: Is this person throwing a lightning bolt? No. Despite appearances, this person is actually pointing in the direction of a bright Iridium flare, a momentary reflection of sunlight off of a communications satellite in orbit around the Earth. As the Iridium satellite orbits, reflective antennas became aligned between the observer and the Sun to create a flash brighter than any star in the night sky. Iridium flares typically last several seconds, longer than most meteors. Also unlike meteors, the flares are symmetric and predictable. The featured flare involved Iridium satellite 15 and occurred over southern Estonia last week. In this well-planned image, a spectacular night sky appears in the background, complete with the central band of our Milky Way Galaxy running vertically up the image center.

Astronomy Picture of the Day – Pluto in Enhanced Color

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 August 31

Pluto in Enhanced Color
Image Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Inst.

 

Explanation: Pluto is more colorful than we can see. Color data and images of our Solar System’s most famous dwarf planet, taken by the robotic New Horizons spacecraft during its flyby in July, have been digitally combined to give an enhanced view of this ancient world sporting an unexpectedly young surface. The featured enhanced color image is not only esthetically pretty but scientifically useful, making surface regions of differing chemical composition visually distinct. For example, the light-colored heart-shaped Tombaugh Regio on the lower right is clearly shown here to be divisible into two regions that are geologically different, with the leftmost lobe Sputnik Planum also appearing unusually smooth. New Horizons now continues on beyond Pluto, will continue to beam back more images and data, and will soon be directed to change course so that it can fly past asteroid 2014 MU69 in 2019 January.

Astronomy Picture of the Day –

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 August 28

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.

Astronomy Picture of the Day – The Large Cloud of Magellan

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 August 27

 

The Large Cloud of Magellan
Image Credit & Copyright: Carlos Fairbairn

 

Explanation: The 16th century Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily visible to southern hemisphere skygazers are known as the Clouds of Magellan, now understood to be satellite galaxies of our much larger, spiral Milky Way galaxy. About 160,000 light-years distant in the constellation Dorado, the Large Magellanic Cloud (LMC) is seen here in a remarkably deep, colorful, image. Spanning about 15,000 light-years or so, it is the most massive of the Milky Way’s satellite galaxies and is the home of the closest supernova in modern times, SN 1987A. The prominent patch below center is 30 Doradus, also known as the magnificent Tarantula Nebula, is a giant star-forming region about 1,000 light-years across.

Astronomy Picture of the Day – Comet Dust over Enchanted Rock

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 August 14

 

 Comet Dust over Enchanted Rock
Image Credit & Copyright: Jared Tennant

 

Explanation: Dusty debris from periodic Comet Swift-Tuttle was swept up by planet Earth this week. Vaporized by their passage through the dense atmosphere at 59 kilometers per second, the tiny grains produced a stream of Perseid meteors. A bright, colorful Perseid meteor flash was captured during this 20 second exposure. It made its ephemeral appearance after midnight on August 12, in the moonless skies over the broad granite dome of Enchanted Rock State Natural Area, central Texas, USA. Below the Perseid meteor, trees stand in silhouette against scattered lights along the horizon and the faint Milky Way, itself cut by dark clouds of interstellar dust.