Image of the Day
by Tom Chao, SPACE.com Producer
Friday, August 30, 2013: The Cone Nebula (NGC 2264) consists of a glowing cloud of ionized gas excited by the surrounding hot, massive young blue stars. Strong winds of particles blow from these stars, shaping the residual gas left from a spent star formation region, creating these structures with striking appearances.
You Wear My Polar Collar
Thursday, August 29, 2013: Cassini spacecraft has now seen Titan’s polar collar in ultraviolet light; previously it was observed by Voyager 2 and the Hubble Space Telescope. Researchers studying the collar’s cause and evolution believe it to be seasonal in nature. This view looks toward the Saturn-facing hemisphere of Titan. Cassini spacecraft took the image on April 13, 2013 at a distance of approximately 1.1 million miles (1.8 million kilometers) from Titan.
Emission Nebula NGC 6357
Wednesday, August 28, 2013: A small part of emission nebula NGC 6357 glows in this image. The nebula lies some 8000 light-years away in the tail of the southern constellation of Scorpius (The Scorpion). The image contains a large amount of ionized and excited hydrogen gas. The cloud bathes in intense ultraviolet radiation (mainly from the open star cluster Pismis 24 which contains some massive, young, blue stars) which it re-emits as visible light, in this distinctive red hue. The star cluster sits outside the frame, but diffuse light from the cluster illuminates the cloud at right center. This close-up of the surrounding nebula displays a mesh of gas, dark dust, and newly born and still forming stars.
Brighter Than a Thousand Thousand Suns
Tuesday, August 27, 2013: This new view shows the Carina nebula as seen in a new image made by NASA’s Spitzer Space Telescope. At the center of the nebula lies Eta Carinae, one of the most massive stars in the galaxy. Its blinding glare sculpts and destroys the surrounding nebula. Eta Carinae represents a true giant of a star. It contains 100 times the mass of our sun, and burns its nuclear fuel so quickly that it blazes at least one million times brighter than the sun. It has brightened and faded over the years, and some astronomers think it could explode as a supernova in the not-too-distant future.
Monday, August 26, 2013: Potentially hazardous near-Earth object 1998 KN3 zips past a cloud of dense gas and dust near the Orion nebula. NEOWISE, the asteroid-hunting portion of the Wide-field Infrared Survey Explorer, or WISE, mission, captured infrared pictures of the asteroid, the yellow-green dot at upper left. The sun warms asteroids to roughly room temperature, so they glow brightly at the infrared wavelengths used by WISE. WISE infrared data reveals that this asteroid is about 0.7 mile (1.1 kilometers) in diameter and reflects about 7 percent of the visible light falling on its surface, making it relatively dark. In this image, blue denotes shorter infrared wavelengths, and red, longer ones. Hotter objects emit shorter-wavelength light, so they appear blue. The coolest gas and dust appears red.
So Many Stars
Credit: Miguel Claro/www.miguelclaro.com
Thursday, August 22, 2013: Astrophotographer Miguel Claro captured the Milky Way in Monte Faperras, Mourão, above Lake Alqueva, in the Alqueva Dark Sky Reserve, Portugal, on July 15, 2013. The photo includes Cygnus (The Swan), with the North America nebula (NGC 7000). Down to the right lies the constellation of Sagittarius and many nebulas: M16, M17, M24, M20, and M8, plus the supergiant star Antares. At the top, the bright star is Vega, in the constellation of Lyra, which forms the well-known Summer Triangle with Deneb and Altair. At the left edge of the image, between the arc of the Milky Way and the horizon, Andromeda Galaxy M31 shines. Above the horizon line, the green/yellow band represents the airglow phenomenon.
Man, Nature, Technology
Wednesday, August 21, 2013: The Southern Hemisphere’s night sky shines in this photo taken by astronomer Håkon Dahle at ESO’s La Silla Observatory in the Atacama Desert of Chile. Dahle appears silhouetted in the foreground while telescope domes loom in the distance. Håkon took this photo during a week-long observing run at the MPG/ESO 2.2 telescope. Although the Milky Way is usually outshined by light pollution or even the moon, the skies at La Silla are so dark that it is possible to see a shadow cast by the light of the Milky Way alone.
Tuesday, August 20, 2013: On Mercury lies Eminescu crater, illuminated by a bright halo of material around its edge. A ray system emanating from nearby crater Xiao Zhao appears on the right side of the image. The shape and coloration of Eminescu crater suggest the familiar sight of the Cat’s Eye Nebula. MESSENGER spacecraft acquired this image on January 3, 2012. Image released August 15, 2013. [See our MESSENGER gallery.]
Across the Sun
Monday, August 19, 2013: On August 6, 2013, the moon made an appearance in NASA’s Solar Dynamics Observatory’s view for almost 90 minutes. This occurrence has happened before, and it provides scientists with useful information. The lunar limb’s sharp edge assists researchers in measuring how light diffracts around the telescope’s optics and filter support grids. This data allows the scientists to fine-tune their instruments more precisely. The sun was imaged here in extreme ultraviolet light, and at the time, a large, bright active region sat right in the central area of the solar disk. SDO orbits about 22,400 miles (36,000 km) above the Earth.
Friday, August 16, 2013: Aurora-spotter Tommy Eliassen took his first aurora photo of the autumn season in Hemnesberget, Nordland, Norway, on August 14, 2013.
You Know Your Straight Line From the Curve
Thursday, August 15, 2013: Streaks of Perseid meteors intersect arcing star trails above the Mt. Lemmon SkyCenter in Arizona. 274 exposures combine in this image by Adam Block, made on August 11, 2013.
How Many Stars?
Wednesday, August 14, 2013: In this image, two spiral galaxies collide, however they lie millions of light-years away, far beyond the cloud of blue and red stars near the merging spiral. This sprinkling of stars is actually an isolated, irregular dwarf galaxy named ESO 489-056. This galaxy floats 16 million light-years from Earth in the constellation of Canis Major (The Greater Dog). It contains a few billion red and blue stars — a very small number when compared to galaxies like the Milky Way, estimated to contain around 200 to 400 billion stars, or the Andromeda Galaxy, which contains one trillion. Image released August 12, 2013.
Two of a Kind
Tuesday, August 13, 2013: Galaxies NGC 799 (below) and NGC 800 (above) lie about 300 million light-years from Earth, in the constellation of Cetus (The Whale). These objects are spiral galaxies, with long arms winding towards bright bulges at their centers. NGC 799 possesses a bar structure, extending from its central bulge, and the spiral arms wind out from the ends of the bar. The small NGC 800 claims three bright spiral arms, whilst NGC 799 only owns two relatively dim, but broad spiral arms. As with all situations when two galaxies sit close enough together, possibly these two galaxies will interact over hundreds of millions of years through gravitational disturbances. Image released August 12, 2013.
Watch the Sun
Monday, August 12, 2013: The SWAP instrument on board ESA’s Proba-2 spacecraft saw the sun on July 30, 2013. SWAP stands for “Sun Watcher using Active Pixel System detector and Image Processing.” The instrument is a small telescope capturing the solar corona at wavelengths corresponding to temperatures of about a million degrees (around 17.1 nanometers). [Get ourwallpaper of this image.]
Will the Circle Be Unbroken?
Friday, August 9, 2013: Galaxy Messier 94 (also known as NGC 4736) appeared historically to possess two quite different rings: a brilliant, compact band around the galaxy’s core, and a faint, broad swath of stars outside its main disk. Astronomers recently discovered that the outer ring, seen here in a deep blue glow of starlight, might actually be an optical illusion. A new, more complete picture of Messier 94 indicates that two separate spiral arms, from our perspective, take on the appearance of a single, unbroken ring.
Thursday, August 8, 2013: The region of Mars to the north of Hesperia Planum, including part of the Tagus Valles, appears in a color-coded overhead digital terrain model acquired by ESA’s Mars Express spacecraft. (Blue indicates lower elevation.) Evidence of a watery past for the larger crater at top left can be seen in the top right of the crater in the shape of a small, winding river channel. The view was taken on 15 January 2013, during orbit 11504.
I’ve Got My Orange Belt
Wednesday, August 7, 2013: An almost full moon hangs above Paranal Observatory in Chile, seconds after the sun has disappeared behind the horizon. The orange glow of the sunset shines on the 1.8-metre VLT Auxiliary Telescopes. The intriguing part of the image hangs in the sky beyond, the atmospheric phenomenon known as the Belt of Venus. The shadow of the Earth creates the grey-bluish shadow above the horizon, and right above glows a pinkish band. The reddened light of the setting sun being backscattered by the Earth’s atmosphere produces the phenomenon. This effect can also appear right after sunset, or a similar effect can appear during a total solar eclipse.
In These Arms
Friday, August 2, 2013: Grand design spiral galaxy Messier 100, located in the southern part of the constellation of Coma Berenices, lies about 55 million light-years from Earth. It faces Earth, presenting a spectacular appearance showing well defined spiral arms. The galaxy also possess the faintest of bar-like structures in the center. The photo shows the main features of a galaxy of this type: clouds of hydrogen gas, glowing redly when re-emitting the energy absorbed from newly born, massive stars; uniform brightness of older, yellowish stars near the center; and black dust trails weaving through the galaxy arms. Messier 100 represents one of the brightest members of the Virgo Cluster, the closest cluster of galaxies to our galaxy, the Milky Way.
Lights of a Summer Night
Credit: Kevin Palmer
Thursday, August 1, 2013: During early July 2013, Astrophotographer Kevin Palmer visited Weinberg King State Park in western Illinois to escape light pollution. He was hoping to make a time-lapse video of the Milky Way rising, but as he tells it: “After setting up my camera to shoot a sequence of images, the high humidity caused the lens to fog over after only 15 minutes. The video was ruined. But I had noticed the fireflies were very active on this night. When I was sitting down trying to look at a star chart, I had fireflies landing and crawling on me. (But I didn’t mind that much, I’ll take fireflies over mosquitoes and ticks any day.) When I got home and looked at the shots before the lens fogged up, I noticed lots of green streaks from fireflies at the bottom of the pictures. A popular astrophotography technique is to combine a series of pictures to make a star trail image that shows the stars’ apparent motion through the night sky. I decided to try something different–I took one image of the night sky and combined it with 10 images of the fireflies.” [See Photos: Stunning Night Sky Stargazing Images of July 2013]
Image of the Day Archives
For older Image of the Day pictures, please visit the Image of the Day archives. Above: NGC 2467.