Image of the Day

Tuesday, Oct. 1, 2013: Astrophotographer Göran Strand sent in a photograph of the moon in Sweden seen between tree branches. He writes in an e-mail to SPACE.com: “The autumn has really started here in northern Sweden. The trees are full of colors, and the air is starting to get cold and clear. Here's a shot ... when the moon was behind a tree full of autumn colors. I think the crescent moon is at its best when visible during daylight against the blue sky.” Image taken Sept. 28, 2013.

— Tom Chao

Monday, Sept. 30, 2013: Spiral galaxy NGC 4274 lies 60 million light years away from us in the constellaion of Coma Berenices. It contains much star fuel, in the form of the gas and dust that give the galaxy’s disk a fluffy appearance. The spiral arms serve as the nurseries that give rise to stars, traced by lines of luminous young blue stars.

— Tom Chao

Friday, Sept. 27, 2013: The Noctis Labyrinthus region of Mars lies high on the Tharsis rise in the upper reaches of the Valles Marineris canyon system. Two types of windblown sediments stand out in this image. A network of pale reddish ridges with a frost-like appearance surrounds bedrock knobs. The pale ridges resemble the simpler “transverse aeolian ridges” (TARs) common in the equatorial regions of Mars. Researchers have an incomplete understanding of TARs, and attribute them variously to dunes produced by reversing winds, coarse grained ripples, or indurated (hardened by fibers) dust deposits.

Dark sand dunes comprise the second type of windblown sediment visible in this image. The dark sand dune just below center displays features similar to active sand dunes observed elsewhere on Mars, including sets of small ripples crisscrossing the top of the dune. The dark dunes consist of grains composed of iron-rich minerals from volcanic rocks on Mars, unlike the pale quartz-rich dunes of Earth. This image clearly shows the dark sand layered on top of the pale TAR network, indicating that the sand dunes appeared more recently than the TARs.

— Tom Chao

Thursday, Sept. 26, 2013: NASA/ESA Hubble Space Telescope's Wide Field Camera 3 photographed the massive galaxy cluster MACS J0152.5-2852 in detail. Almost every object seen in the image represents a galaxy containing billions of stars. Galaxies do not randomly distribute themselves in space, rather concentrating by the hundreds through the action of mutual gravity. Elliptical galaxies, similar to the yellow fuzzy objects seen in the image, most often appear close to the center of galaxy clusters. Spiral galaxies, indicated by bluish patches, usually lie further out, more isolated.

— Tom Chao

Wednesday, Sept. 25, 2013: The Soyuz rocket rises into position, after it rolled out to the launch pad by train on Sept. 23, 2013, at the Baikonur Cosmodrome in Kazakhstan. Launch of the Soyuz rocket is scheduled for September 26, 2013, sending Expedition 37 Soyuz Commander Oleg Kotov, NASA Flight Engineer Michael Hopkins and Russian Flight Engineer Sergei Ryazansky on a mission lasting five-and-one-half months aboard the International Space Station.

— Tom Chao

Tuesday, Sept. 24, 2013: ESO’s VISTA telescope has spotted a brown dwarf nicknamed VVV BD001, seen at the very center of this image. It represents the first new brown dwarf spotted in our cosmic neighborhood as part of the VVV Survey. VVV BD001 lies about 55 light-years away from us, towards the crowded center of our galaxy. Astronomers often refer to brown dwarfs as “failed stars,” as they loom larger in size than planets like Jupiter, but don’t make it to the size of stars. This dwarf possesses two peculiarities: First, it is the first one found towards the center of the Milky Way, one of the most crowded regions of the sky. Second, it belongs to an unusual class of stars known as “unusually blue brown dwarfs” — it is unclear why these stars are bluer than expected.

— Tom Chao

Monday, Sept. 23, 2013: Star HD 184738 (AKA Campbell’s hydrogen star) appears within plumes of reddish glowing gases, including hydrogen and nitrogen. HD 184738 lies at the center of a small planetary nebula. Astronomers consider the star a [WC] star, a rare class resembling more massive counterparts, Wolf-Rayet stars. [WC] stars consist of low-mass sun-like stars at the end of their lives. While these stars have recently ejected much of their original mass, the hot stellar core still loses mass at a high rate, creating a hot wind. These winds cause them to resemble Wolf-Rayet stars. Wolf-Rayet stars are hot stars, perhaps 20 times more massive than the sun, rapidly blowing away material and losing mass.

— Tom Chao

Friday, Sept. 20, 2013: Astrophotographer Anthony Lynch sent in this photo of the Harvest Moon, taken at Phoenix Park in Dublin, Ireland, September 2013. He writes in an e-mail to SPACE.com, “I went out to an old fort on a hill to catch tonight's harvest moon. [W]hen I [saw] some deer, I ran down the hill so I could get them on the horizon with the moon. I had to keep making noises so they would look up for the shot, otherwise they just looked like sheep.”

— Tom Chao

Thursday, Sept. 19, 2013: Orbital Sciences Corp. launched its Cygnus cargo capsule aboard an Antares rocket from NASA's Wallops Island Flight Facility on at 10:58 a.m. EDT (1458 GMT) on Sept. 18, 2013. The demonstration flight should arrive at the International Space Station on Sunday, Sept. 22, after a series of in-flight tests. [See full story.]

— Tom Chao

Wednesday, Sept. 18, 2013: Stargazer Panos Evripiotis sent in a photo of the Milky Way seen over the Temple of Demeter on the island of Naxos, Greece. Photo taken Sept. 4, 2013.

— Tom Chao

Tuesday, Sept. 17, 2013: A "mini-jet" appears in the dynamic F ring of Saturn. Saturn's A ring, including the Keeler gap and a small part of the Encke gap at the upper-right, also appears. Imaging scientists think the mini-jets stem from low-speed collisions in the F ring ejecting dusty material from the ring's core. Cassini spacecraft took this image in visible light on June 20, 2013, at a distance of approximately 841,000 miles (1.4 million kilometers) from Saturn.

— Tom Chao

Monday, Sept. 16 , 2013: Auroramax automated camera photographed this auroral display in Canada's Northwest Territory on Sept. 13, 2013.

— Tom Chao

Friday, Sept. 13, 2013: This MESSENGER spacecraft image of planet Mercury shows a landform known as a lobate scarp, the nearly vertical ridge at the top center of the image. Scientists believe these scarps form when one block of crust thrusts up and over another, in response to the global contraction of Mercury as its core cooled and solidified. These scarps frequently cross-cut impact craters of all sizes. However, this particular scarp represents one of only very few scarps that display thin, linear depressions on their upper surfaces. Possibly these features are graben — fault-bounded troughs that form when rock is extended — like those seen in Caloris basin (a large impact crater on Mercury). If true, then these graben are among the only such structures known to occur outside of volcanically flooded impact basins and craters.

— Tom Chao

Thursday, Sept. 12, 2013: This photo taken by the Solar Dynamics Observatory (SDO) shows magnetic field lines emerging from several active regions on the sun, Sept. 4-5, 2013. The easily observable lines reached from one magnetic pole to another. Extreme ultraviolet light reveals tracings of charged particles along the magnetic field lines. The bright, active regions represent areas of intense magnetic forces. SDO provides imaging with a level of detail previously unavailable.

— Tom Chao

Wednesday, Sept. 11, 2013: Dwarf galaxy ESO 540-31 lies just over 11 million light-years from Earth, in the constellation of Cetus (The Whale). Many other galaxies fill the background of this image, and they lie at vast distances from Earth. Dwarf galaxies represent some of the the smaller and dimmer members of the galactic family, typically only containing around a few hundred million stars. This number pales in comparison to spiral galaxies like our Milky Way, which contain hundreds of billions of stars. Image released Sept. 9, 2013.

— Tom Chao

Tuesday, Sept. 10, 2013: Saturn's rings appear to arc over the planet in this image from the Cassini spacecraft. Cassini spacecraft took the image with its wide-angle camera on June 15, 2013, using a spectral filter sensitive to wavelengths of near-infrared light centered at 705 nanometers. Cassini acquired the view at a distance of approximately 657,000 miles (1.1 million kilometers) from Saturn.

— Tom Chao

Monday, Sept. 9, 2013: Spiral galaxy IC 2560 lies over 110 million light-years away from Earth in the constellation of Antlia (The Air Pump). It represents a relatively nearby spiral galaxy, making up part of the Antlia cluster — a group of over 200 galaxies held together by gravity. This cluster unusually appears to have no dominant galaxy in it. Astronomers call this spiral a Seyfert-2 galaxy, a kind of spiral galaxy characterised by an extremely bright nucleus. The bright center of the galaxy may be caused by the ejection of huge amounts of super-hot gas from the region around a central black hole. The unusual name of the constellation traces back to French astronomer Abbé Nicolas Louis de Lacaille, who named originally named Antlia, “antlia pneumatica,” in honor of the invention of the air pump in the 17th century.

— Tom Chao

Friday, Sept. 6, 2013: Astrophotographer Jerry Payne sent in a photo of star trails reflected in water covering the Bonneville Salt Flats near Wendover, Nevada. Payne writes in an e-mail to SPACE.com: “The photo consists of a about 2 hours worth of 30-second exposures summed using Startrails.exe software ... This area of the salt flats was covered with a thin layer of water, from either snow-melt or a recent storm. That plus a cloudless night, no moon, and extremely calm wind conditions allowed for this photo.” Photo submitted September 3, 2013.

— Tom Chao

Thursday, Sept. 5, 2013: ESA’s Herschel space observatory sees the Orion A star-formation cloud in this image. The Orion Nebula lies within the central bright region of this scene, where massive star formation occurs most intensely. Cooler gas and dust glows in red and yellow, with point-like sources representing the seeds of new stars.

— Tom Chao

Wednesday, Sept. 4, 2013: Messier 74, a spiral galaxy with well-defined whirling arms, seems stunning enough. However, this image contains another amazing sight: a Type II supernova named SN2013ej, visible as the brightest star at the bottom left of the image. SN2013ej represents the third supernova spotted in Messier 74 since the turn of the millennium, the other two being SN 2002ap and SN 2003gd. The latest supernova was first reported on July 25, 2013 by the KAIT telescope team in California. Amateur astronomer Christina Feliciano took the first "precovery image," using the public access SLOOH Space Camera to peer at the region in the days and hours immediately before the explosion.

— Tom Chao

[Answer to yesterday’s Back-to-School Geography Quiz: Lake Ontario.]

Tuesday, Sept. 3, 2013: It’s again that time of year when you head back to school, students! Here’s a quick quiz for you: Astronaut Karen Nyberg tweeted this photo of the Earth taken from the International Space Station on Aug. 25, 2013. Who knows what this geographical feature is? Hint: It’s a body of water. Answer tomorrow.

— Tom Chao

Monday, Sept. 2, 2013: Happy Labor Day from SPACE.com. A Delta 4 Heavy rocket launched a secret satellite for the National Reconnaissance Office (NRO) from Vandenburg Air Force Base in California on Aug. 28, 2013. The NROL-65 mission supports national defense. The Delta 4 Heavy, built by ULA and first flown in 2004, represents the biggest, most powerful American rocket in operation today. The 235-foot-tall (72-meter) launcher produces about 2 million pounds of thrust at liftoff, according to ULA officials. Two strap-on boosters give the rocket a distinctive appearance.

— Tom Chao

For older Image of the Day pictures, please visit the Image of the Day archives. Above: NGC 2467.