Thursday, September 1, 2011: At Cape Canaveral in Florida, half of the clamshell-shaped Delta payload fairing closes around NASA's twin Gravity Recovery and Interior Laboratory spacecraft. Scheduled to launch September 8, 2011, the two spacecraft will fly in tandem orbits around the moon for several months to measure its gravity field.
— Tom Chao
Friday, September 2, 2011: Researchers from the University of Tokyo and the National Astronomical Society of Japan (NAOJ) have identified the location of red star-forming galaxies around a galaxy cluster situated four billion light years distant from Earth. Such "red-burning galaxies" are in a transitional phase from a young generation of galaxies to an older one, and may demonstrate the dramatic evolution of galaxies in the environment surrounding the cluster. The main image shows a panoramic view of the CL0939+4713 cluster located 4 billion light years away from Earth. Top right: Close-up view of the central cluster region. Bottom right: Example of the concentration of red-burning galaxies, marked with red squares.
— Tom Chao
Monday, September 5, 2011: NASA's modified Boeing 747 Shuttle Carrier Aircraft briefly flew in formation over the Edwards Air Force Base Test Range on Aug. 2, 2011. The aircraft were scheduled to be in the air on the same day, NASA 911 (foreground) on a flight crew proficiency flight, and NASA 905 (rear) on a functional check flight following maintenance operations. NASA uses these aircraft to ferry space shuttle orbiters from landing sites such as Edwards Air Force Base in California back to Kennedy Space Center in Florida. Struts for attaching the space shuttle orbiters protrude from the tops of the aircraft.
— Tom Chao
Tuesday, September 6, 2011: An astronaut in the International Space Station caught this nighttime view of northern India and northern Pakistan. The capital cities of Islamabad, Pakistan and New Delhi, India, glow the brightest at bottom and top of this image, respectively. Between them lies another city, Lahore, with numerous highways snaking from it. The distinct orange line just above Lahore that divides the image in half is the border zone between the two countries. At left, the grayish area contains the partly cloud-covered Himalayas. In the background, airglow hangs 50 miles (80 kilometers) above the Earth.
— Tom Chao
Wednesday, September 7, 2011: NASA's Cassini spacecraft made a close pass of Saturn's icy moon Helene on June 18, 2011. Cassini flew within 4,330 miles (6,968 kilometers) of Helene's surface. It was the second closest approach to Helene of the mission. Cassini passed from Helene's night side to the moon's sunlit side. It also captured images of the Saturn-facing side of the moon in sunlight, a region that was only illuminated by sunlight reflected off Saturn the last time Cassini was close, in March 2010.
— Tom Chao
Thursday, September 8, 2011: Today marks the 45th anniversary of "Star Trek," the TV series that debuted on September 8. 1966, and went on to spawn an quadrant-sized quantity of spin-offs, movies, and merchandise. This photograph shows the original model of the fictional spaceship U. S. S. Enterprise (NCC-1701) that appeared in the television series. First conceptualized in 4-inch and 3-foot versions, the final model stretches 11 feet, primarily constructed out of poplar wood, vacu-formed plastic, and rolled sheet metal tubes. Paramount donated the model to the National Collection of the Smithsonian Institution in 1974. It currently resides in the National Air and Space Museum (no longer suspended as shown). To see it, visitors must go to the lower level of the museum and venture to the very rear of the gift shop, where it sits amongst the sale items. Judging from comments posted on online forums, some fans feel the restored paint scheme does not reflect the appearance of the model when originally filmed.
— Tom Chao
Friday, September 9, 2011: The European Southern Observatory tested its new Wendelstein laser guide star unit at the Allgäu Public Observatory in southwestern Bavaria, Germany, on August 18, 2011. The observatory shot a powerful laser beam into the atmosphere while, coincidentally, lighting flashed in the distance as the photographer recorded the test. The laser emits a 20-watt beam, but the power in a bolt of lightning peaks at a trillion watts, albeit for just a fraction of a second. ESO commented that the photograph provided "a very visual demonstration of why ESO's telescopes are in Chile, and not in Germany."
— Tom Chao
Monday, September 12, 2011: Holden crater is 87 miles (140 km across). It is located in the southern highlands of Mars. The image was acquired by ESA's Mars Express spacecraft on August 15, 2009. Neighboring Eberswalde crater, at the top left of this image, shows distinct traces of a delta, suggesting that a lake of liquid water used to exist there.
— Tom Chao
Tuesday, September 13, 2011: The Delta 2 Heavy rocket carrying NASA’s twin Gravity Recovery and Interior Laboratory (GRAIL) mission blasts off from Space Launch Complex 17B on Cape Canaveral Air Force Station in Florida. The spacecraft launched at 9:08:52 a.m. EDT on Sept. 10, 2011, en route to lunar orbit, where they will study the moon's gravity.
— Tom Chao
Wednesday, September 14, 2011: Pete Murray caught the Harvest Moon on September 11, 2011, at Dana Point Harbor, CA, during the Tall Ships Parade.
— Tom Chao
Thursday, September 15, 2011: A still from a NASA-produced animation imagines the new Space Launch System rocket flying through the clouds to space.
— Tom Chao
Friday, September 16, 2011: ESA's Herschel infrared space observatory discovered that galaxy collisions aren't always required for vigorous star birth in galaxy evolution. The finding overturns a long-held assumption about how galaxies evolve. In the present universe, high birth rates of stars always seem to be triggered by galaxies colliding with each other. Herschel looked at galaxies very distant, seeing them as they were billions of years ago, and thus helped researchers draw the conclusion that star birth rate depends on the quantity of gas galaxies contain, not whether they are colliding. This image shows streams of cold gas feeding a galaxy.
— Tom Chao
Monday, September 19, 2011: In the constellation of Aquila (the Eagle), a dying star known as IRAS 19024+0044 ejects a starfish-shaped cloud of gas and dust, as it slowly makes the transition to a white dwarf surrounded by a planetary nebula. Five blue lobes extend from the central star, although their formation is not entirely understood.
— Tom Chao
Tuesday, September 20, 2011: In Chile's Atacama Desert, at the Paranal Observatory, the moon rises reddishly with one of the four Auxiliary Telescopes standing in the foreground, on September 12, 2011. When the moon is close to the horizon, its reflected light travels through more of the atmosphere, so scattering is increased. As red light scatters less than green or blue, the moon appears reddened. However, the reddening effect is less pronounced at sites like Paranal, where the air is very clear.
— Tom Chao
Wednesday, September 21, 2011: Near the "sword" of the constellation Orion lies an active stellar nursery containing thousands of young stars and developing protostars. Stars more massive than our sun light the Orion nebula, seen here as the bright region near the center of the image. To the north of the Orion nebula, a dark filamentary cloud of cold dust and gas, over 5 light-years in length, contains striking red protostars that line the hilt of Orion's "sword."
— Tom Chao
Thursday, September 22, 2011: Ground support vehicles can be seen chasing the Soyuz TMA-21 spacecraft as it lands with Expedition 28 Commander Andrey Borisenko, and Flight Engineers Ron Garan, and Alexander Samokutyaev in a remote area outside of the town of Zhezkazgan, Kazakhstan, on Friday, Sept. 16, 2011. NASA Astronaut Garan, Russian Cosmonauts Borisenko and Samokutyaev are returning from more than five months onboard the International Space Station where they served as members of the Expedition 27 and 28 crews.
— Tom Chao
Friday, September 23, 2011: An enormous X class (strongest category) solar flare emerges from the sun, at the bright spot in the lower part of this image. The flare erupted September 7, 2011, continuing into September 8. The Solar Dynamics Observatory took the image in extreme ultraviolet (UV) light.
— Tom Chao
Monday, September 26, 2011: An Ariane 5 launcher blazes off the launch pad at Europe’s Spaceport in French Guiana on September 21, 2011. The rocket placed two telecommunications satellites, Arabsat-5C and SES-2, into their planned transfer orbits.
— Tom Chao
Tuesday, September 27, 2011: Sunspot 1302 (pictured in a recent Image of the Day) threatens to emit further X-class solar flares, the strongest class of solar flares. [Full Story]
— Tom Chao
Wednesday, September 28, 2011: At the end of Martian summer, warm weather causes portions of the vast carbon-dioxide ice cap near the Martian south pole to sublimate directly into gas. Pits begin to appear and expand where the carbon dioxide dry ice disappears. The pits appear to be lined with gold, but the composition of the dust that highlights the pit walls remains unknown.
— Tom Chao
Thursday, September 29, 2011: Taken by an astronaut aboard the International Space Station, this image shows the continent of Australia glowing with orange wildfires (some may be intentionally set agricultural fires), with smoke faintly visible in the night sky. The greenish line above curve of the Earth is caused by atmospheric airglow.
— Tom Chao
Friday, September 30, 2011: Dust mixed in interstellar gas gives the mistaken impression that portions of our galaxy don't contain stars. Elsewhere, the thinner portions of the nebula scatters the light of nearby blue stars.
— Tom Chao
For older Image of the Day pictures, please visit the Image of the Day archives. Above: NGC 2467.
