2005 October 8

Peculiar Arp 295

Credit: Arne Henden (US Naval Observatory, Flagstaff)

Image Processed by Al Kelly

Explanation: A spectacular bridge of stars and gas stretches for nearly 250,000 light-years and joins this famous peculiar pair of galaxies cataloged as Arp 295. The cosmic bridge between the galaxies and the long tail extending below and right of picture center are strong evidence that these two immense star systems have passed close to each other in the past, allowing violent tides induced by mutual gravity to create the eye-catching plumes of stellar material. While such interactions are drawn out over billions of years, repeated close passages should ultimately result in the merger of this pair of galaxies into a larger single galaxy of stars. Although this scenario does look peculiar, galactic mergers are thought to be common, with Arp 295 representing an early stage of this inevitable process. The Arp 295 pair are the largest of a loose grouping of galaxies about 270 million light-years distant toward the constellation Aquarius. This deep color image of the region was recorded in September 2003 using the USNO 1 meter telescope near Flagstaff, Arizona.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 28

October Mars

Credit & Copyright: Chris Cook

Explanation: This October, Mars has become a bright, yellowish star in planet Earth's sky as it approaches oppositon, the period when Mars and Earth pass close as they orbit the Sun. How close is Mars? A mere 70 million kilometers or so, close enough to allow Earth-bound astronomers excellent views of the alluring Red Planet. For example, this series of sharp Mars images follows the development of a dust storm as the planet rotates from right to left. The telescopic views clearly show details of the martian surface, including the planet's southern ice cap (top) and hood of clouds over the north pole at the bottom edge. The dust storm itself is visible as a light yellowish band across an otherwise dark region in the southern hemisphere. Even if a telescope isn't handy, be sure to check out Mars soon. It will continue to shine brightly in the night over the coming days.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 9

Rollout of Soyuz TMA-2 Aboard an R7 Rocket

Credit: Scott Andrews, NASA

Explanation: It takes a big rocket to go into space. In 2003 April, this huge Russian rocket was launched toward Earth-orbiting International Space Station (ISS), carrying two astronauts who will make up the new Expedition 7 crew. Seen here during rollout at the Baikonur Cosmodrome, the rocket's white top is actually the Soyuz TMA-2, the most recent version of the longest serving type of human spacecraft. The base is a Russian R7 rocket, originally developed as a prototype Intercontinental Ballistic Missile in 1957. The rocket spans the width of a football field and has a fueled mass of about half a million kilograms. Russian rockets like this remain a primary transportation system to the International Space Station (ISS). Last week, a similar rocket successfully launched a spaceflight participant and two Expedition 12 astronauts to the space station.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 22

Ring Galaxy AM 0644-741 from Hubble

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 has since moved out of the frame taken by the Hubble Space Telescope and released to commemorate the anniversary of Hubble's launch in 1990. Ring galaxy AM 0644-741 lies about 300 million light years away.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 31

A Martian Halloween

Credit & Copyright: Wally Pacholka (Astropics.com)

Explanation: From sunset to sunrise, an unusually bright yellowish orb will hang in the sky this Halloween: Mars. Yesterday, Earth passed Mars as they orbited the Sun, bringing Mars closer than it will be for the next thirteen years. Tonight though, Mars will be nearly as bright as last night, a beacon of extraterrestrial spookiness. Opposite the Sun, Mars will rise just when the Sun sets, set just when the Sun rises, and be visible the entire night. Mars will not always be the brightest object in tonight's sky, though. Brighter than even Mars, almost spooky Venus will light up the western horizon for a brief time just after sunset. Please have a safe and happy All Hallows Eve.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 19

On the Possibility of Ascending to Mars

Image Credit & Copyright: Fred Espenak ( www.MrEclipse.com)

Explanation: On another October 19, in 1899, a 17 year-old Robert Goddard climbed a cherry tree on a beautiful autumn afternoon in Worcester, Massachusetts. Inspired by H.G. Wells' War of the Worlds and gazing out across a meadow, young Goddard imagined it would be wonderful to make a device that had the possibility of ascending to Mars. Forever more he felt his life had a purpose and in the following years his diary entries record October 19th as "Anniversary Day", the anniversary of his ascent into the cherry tree. By 1926 he had designed, built, and flown the world's first liquid fuel rocket. Mars is just visible through the trees at the lower right in this dramatic sky view that also features the Moon and Venus -- all visited by liquid fuel rockets constructed on principles developed by Goddard.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 18

AE Aurigae: The Flaming Star

Credit & Copyright: Thomas V. Davis (tvdavisastropix.com)

Explanation: Is star AE Aurigae on fire? No. Even though AE Aurigae is named the flaming star, the surrounding nebula IC 405 is named the Flaming Star Nebula, and the region appears to harbor red smoke, there is no fire. Fire, typically defined as the rapid molecular acquisition of oxygen, happens only when sufficient oxygen is present and is not important in such high-energy, low-oxygen environments such as stars. The material that appears as smoke is mostly interstellar hydrogen, but does contain smoke-like dark filaments of carbon-rich dust grains. The bright star AE Aurigae, visible just below the image center, is so hot it is blue, emitting light so energetic it knocks electrons away from surrounding gas. When a proton recaptures an electron, red light is frequently emitted, as seen in the surrounding emission nebula. Pictured above, the Flaming Star nebula lies about 1,500 light years distant, spans about 5 light years, and is visible with a small telescope toward the constellation of the Charioteer (Auriga).

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC

2005 October 1

NGC 613: Spiral of Dust and Stars

Credit: M. Neeser (Univ.-Sternwarte M�nchen), P. Barthel (Kapteyn Astron. Institute), H. Heyer, H. Boffin (ESO), ESO

Explanation: When morning twilight came to the Paranal Observatory in Chile, astronomers Mark Neeser and Peter Barthel interrupted their search for faint quasars, billions of light-years away. And just for a moment, they used Very Large Telescopes at the European Southern Observatory to appreciate the beauty of the nearby Universe. One result was this stunning view of beautiful barred spiral galaxy NGC 613, a mere 65 million light-years away in the southern constellation Sculptor. Over 100 thousand light-years across, NGC 613 seems to have more than its fair share of spiral arms laced with cosmic dust clouds and bright star forming regions near the ends of a dominant central bar. Radio emission indicates the presence of a massive black hole at the center of NGC 613.

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

NASA Official: Jay Norris.

A service of: EUD at NASA / GSFC