Posted on by Nancy Atkinson

Two Views of a Lopsided Galaxy

This picture of the Meathook Galaxy (NGC 2442) was taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla, Chile. Credit: ESO

[/caption]

From an ESO press release:

The Meathook Galaxy, or NGC 2442, has a dramatically lopsided shape. One spiral arm is tightly folded in on itself and host to a recent supernova, while the other, dotted with recent star formation, extends far out from the nucleus. The MPG/ESO 2.2-metre telescope and the NASA/ESA Hubble Space Telescope have captured two contrasting views of this asymmetric spiral galaxy.

The Meathook Galaxy, or NGC 2442, in the southern constellation of Volans (The Flying Fish), is easily recognised for its asymmetric spiral arms. The galaxy’s lopsided appearance is thought to be due to gravitational interactions with another galaxy at some point in its history — though astronomers have not so far been able to positively identify the culprit.

This broad view, taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla, Chile, very clearly shows the double hook shape that gives the galaxy its nickname. This image also captures several other galaxies close to NGC 2442 as well as many more remote galaxies that form a rich backdrop. Although the Wide Field Imager, on the ground, cannot approach the sharpness of images from Hubble in space, it can cover a much bigger section of sky in a single exposure. The two tools often provide complementary information to astronomers.

This close-up Hubble view of the Meathook Galaxy (NGC 2442) focuses on the more compact of its two asymmetric spiral arms as well as the central regions. The spiral arm was the location of a supernova that exploded in 1999. These observations were made in 2006 in order to study the aftermath of this supernova. Ground-based data from MPG/ESO 2.2-metre telescope were used to fill out parts of the edges of this image. Credit: NASA/ESA and ESO

A close-up image from the NASA/ESA Hubble Space Telescope (eso1115b) focuses on the galaxy’s nucleus and the more compact of its two spiral arms. In 1999, a massive star at the end of its life exploded in this arm in a supernova. By comparing older ground-based observations, previous Hubble images made in 2001, and these shots taken in late 2006, astronomers have been able to study in detail what happened to the star in its dying moments. By the time of this image the supernova itself had faded and is not visible.

ESO’s observations also highlight the other end of the life cycle of stars from Hubble. Dotted across much of the galaxy, and particularly in the longer of the two spiral arms, are patches of pink and red. This colour comes from hydrogen gas in star-forming regions: as the powerful radiation of new-born stars excites the gas in the clouds they formed from, it glows a bright shade of red.

The interaction with another galaxy that gave the Meathook Galaxy its unusual asymmetric shape is also likely to have been the trigger of this recent episode of star formation. The same tidal forces that deformed the galaxy disrupted clouds of gas and triggered their gravitational collapse.

Posted on by Jason Major

USPS Commemorates Spaceflight Past and Present

Postage stamps honoring Mercury astronaut Alan Shepard, America’s first man in space, and NASA’s MESSENGER probe, the first spacecraft to orbit Mercury, will be presented on May 4th at a public event taking place at the Aviation Heritage Park in Dayton, Ohio.

Alan Shepard poses in his pressure suit before his historic flight on May 5, 1961. Credit: NASA.

The first stamp salutes NASA’s Project Mercury, America’s first manned spaceflight program, and astronaut Alan B. Shepard, Jr.’s historic sub-orbital flight on May 5, 1961 aboard the spacecraft Freedom 7.

The other stamp highlights NASA’s MESSENGER spacecraft currently exploring the planet Mercury. It successfully established orbit around the planet on March 18, 2011, the first spacecraft ever to do so.

These two historic missions frame a remarkable fifty-year period in which the U.S. has advanced space exploration through more than 1,500 manned and unmanned flights.

Both stamps were designed by professional artist Donato Giancola of Brooklyn, NY, who based the stamp designs on NASA photos and images.

Both stamps will be issued as “Forever Stamps” for use in mailing a one-ounce letter. Regardless of when the stamps are purchased and no matter how postage prices may change, these stamps will always be equal to the current First-Class Mail one-ounce price.

NASA's Mercury-Redstone 3 rocket, with Alan Shepard inside the Freedom 7 capsule, launches from Cape Canaveral on May 5, 1961. Credit: NASA.

Stamps are now available online at the US Postal Service store here.

Posted on by Nancy Atkinson

Hit and Run Asteroid Caused Scheila’s Comet-like Behavior

Faint dust plumes bookend asteroid (596) Scheila, which is overexposed in this composite. Visible and ultraviolet images from Swift's UVOT (circled) are merged with a Digital Sky Survey image of the same region. The UVOT images were acquired on Dec. 15, 2010, when the asteroid was about 232 million miles from Earth. Credit: NASA/Swift/DSS/D. Bodewits (UMD)

Asteroid or comet? That was the question astronomers were asking after an asteroid named Scheila had unexpectedly brightened, and seemingly sprouted a tail and coma. But follow-up observations by the Swift satellite and the Hubble Space Telescope show that these changes likely occurred after Scheila was struck by a much smaller asteroid.

“Collisions between asteroids create rock fragments, from fine dust to huge boulders, that impact planets and their moons,” said Dennis Bodewits, an astronomer at the University of Maryland in College Park and lead author of the Swift study. “Yet this is the first time we’ve been able to catch one just weeks after the smash-up, long before the evidence fades away.”

[/caption]

On Dec. 11, 2010, images from the University of Arizona’s Catalina Sky Survey, a project of NASA’s Near Earth Object Observations Program, revealed the Scheila to be twice as bright as expected and immersed in a faint comet-like glow. Looking through the survey’s archived images, astronomers inferred the outburst began between Nov. 11 and Dec. 3.

Three days after the outburst was announced, Swift’s Ultraviolet/Optical Telescope (UVOT) captured multiple images and a spectrum of the asteroid. Ultraviolet sunlight breaks up the gas molecules surrounding comets; water, for example, is transformed into hydroxyl (OH) and hydrogen (H). But none of the emissions most commonly identified in comets — such as hydroxyl or cyanogen (CN) — showed up in the UVOT spectrum. The absence of gas around Scheila led the Swift team to reject the idea that Scheila was actually a comet and that exposed ice accounted for the brightening.

Hubble observed the asteroid’s fading dust cloud on Dec. 27, 2010, and Jan. 4, 2011. Images show the asteroid was flanked in the north by a bright dust plume and in the south by a fainter one. The dual plumes formed as small dust particles excavated by the impact were pushed away from the asteroid by sunlight.

The science teams from the two space observatories found the observations were best explained by a collision with a small asteroid impacting Scheila’s surface at an angle of less than 30 degrees, leaving a crater 1,000 feet across. Laboratory experiments show a more direct strike probably wouldn’t have produced two distinct dust plumes. The researchers estimated the crash ejected more than 660,000 tons of dust–equivalent to nearly twice the mass of the Empire State Building.

The Hubble Space Telescope imaged (596) Scheila on Dec. 27, 2010, when the asteroid was about 218 million miles away. Scheila is overexposed in this image to reveal the faint dust features. The asteroid is surrounded by a C-shaped cloud of particles and displays a linear dust tail in this visible-light picture acquired by Hubble's Wide Field Camera 3. Because Hubble tracked the asteroid during the exposure, the star images are trailed. Credit: NASA/ESA/D. Jewitt (UCLA)

“The Hubble data are most simply explained by the impact, at 11,000 mph, of a previously unknown asteroid about 100 feet in diameter,” said Hubble team leader David Jewitt at the University of California in Los Angeles. Hubble did not see any discrete collision fragments, unlike its 2009 observations of P/2010 A2, the first identified asteroid collision.

Scheila is approximately 113 km (70 miles) across and orbits the sun every five years.

“The dust cloud around Scheila could be 10,000 times as massive as the one ejected from comet 9P/Tempel 1 during NASA’s UMD-led Deep Impact mission,” said co-author Michael Kelley, also at the University of Maryland. “Collisions allow us to peek inside comets and asteroids. Ejecta kicked up by Deep Impact contained lots of ice, and the absence of ice in Scheila’s interior shows that it’s entirely unlike comets.”

The studies will appear in the May 20 edition of The Astrophysical Journal Letters.

Source: NASA Goddard

Posted on by Nancy Atkinson

Take a Look: Huge Asteroid to Fly By Earth in November

This radar image of asteroid 2005 YU55 was generated from data taken in April of 2010 by the Arecibo Radar Telescope in Puerto Rico. Image credit: NASA/Cornell/Arecibo

[/caption]

A large space rock will pass close to Earth on November 8, 2011 and astronomers are anticipating the chance to see asteroid 2005 YU55 close up. Just like meteorites offer a free “sample return” mission from space, this close flyby is akin to sending a spacecraft to fly by an asteroid – just like how the Rosetta mission recently flew by asteroid Lutetia – but this time, no rocket is required. Astronomers are making sure Spaceship Earth will have all available resources trained on 2005 YU55 as it makes its closest approach, and this might be a chance for you to see the asteroid for yourself, as well.

“While near-Earth objects of this size have flown within a lunar distance in the past, we did not have the foreknowledge and technology to take advantage of the opportunity,” said Barbara Wilson, a scientist at JPL. “When it flies past, it should be a great opportunity for science instruments on the ground to get a good look.”

2005 YU55 is about 400 meters [1,300 feet] wide, and closest approach will be about 325,000 kilometers (201,700 miles) from Earth.

“This is the largest space rock we have identified that will come this close until 2028,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office at JPL, and Yeomans assured that we are in no danger from this asteroid.

“YU55 poses no threat of an Earth collision over, at the very least, the next 100 years,” he said. “During its closest approach, its gravitational effect on the Earth will be so miniscule as to be immeasurable. It will not affect the tides or anything else.”

Astronomers estimate that asteroids the size of YU55 come this close to Earth about every 25 years. We just haven’t had this much advance warning – a testament to the work that Yeomans and his team does at the NEO Program in detecting asteroids and detecting them early.

So, here’s a chance for a close-up look. The 70-meter (230-foot) newly upgraded Goldstone antenna in California, part of NASA’s Deep Space Network, will be imaging the asteroid with radar.

“Using the Goldstone radar operating with the software and hardware upgrades, the resulting images of YU55 could come in with resolution as fine as 4 meters per pixel,” said Benner. “We’re talking about getting down to the kind of surface detail you dream of when you have a spacecraft fly by one of these targets.”

Combining the radar images with ground-based optical and near-infrared observations, astronomers should get a good overview of one of the larger near-Earth objects.

Look for more information in the near future about observing campaigns for amateur astronomers of this object. At first, 2005 YU55 will be too close to the sun and too faint for optical observers. But late in the day (Universal Time) on Nov. 8, and early on Nov. 9, the asteroid could reach about 11th magnitude for several hours before it fades as its distance rapidly increases.

This radar image of asteroid 2005 YU55 was generated from data taken in April of 2010 by the Arecibo Radar Telescope in Puerto Rico. Image credit: NASA/Cornell/Arecibo

2005 YU55 was discovered in December 2005 by Robert McMillan, head of the NASA-funded Spacewatch Program at the University of Arizona, Tucson. In April 2010, Mike Nolan and colleagues at the Arecibo Observatory in Puerto Rico generated some ghostly images of 2005 YU55 when the asteroid was about 2.3 million kilometers (1.5 million miles) from Earth.

“The best resolution of the radar images was 7.5 meters [25 feet] per pixel,” said JPL radar astronomer Lance Benner. “When 2005 YU55 returns this fall … the asteroid will be seven times closer. We’re expecting some very detailed radar images.”

Radar antennas beam directed microwave signals at their celestial targets — which can be as close as our moon and as far away as the moons of Saturn. These signals bounce off the target, and the resulting “echo” is collected and precisely collated to create radar images, which can be used to reconstruct detailed three-dimensional models of the object. This defines its rotation precisely and gives scientists a good idea of the object’s surface roughness. They can even make out surface features, and astronomers hope to see boulders and craters on the surfaces of 2005 YU55, as well as detailing the mineral composition of the asteroid.

“This is a C-type asteroid, and those are thought to be representative of the primordial materials from which our solar system was formed,” said Wilson. “This flyby will be an excellent opportunity to test how we study, document and quantify which asteroids would be most appropriate for a future human mission.”
Yeomans said this is a great opportunity for scientific discovery. “So stay tuned. This is going to be fun.”

Source: JPL

Posted on by Nancy Atkinson

Stealth Unmanned Combat Vehicle Makes First Flight

The Boeing Phantom Ray unmanned airborne system (UAS) on its first flight. Credit: Boeing.

[/caption]

Looking like something straight from a 1950’s science fiction magazine, the stealthy Phantom Ray unmanned airborne system (UAS) successfully completed its first flight on April 27, 2011 at NASA’s Dryden Flight Research Center at Edwards Air Force Base in California. The 17-minute flight took place following a series of high-speed taxi tests in March that validated ground guidance, navigation and control and verified mission planning, pilot interface and operational procedures. The Phantom Ray is a demonstrator aircraft, about the size of a fighter jet, developed to test operations such as air surveillance, ground attack and autonomous aerial refueling missions. During the test flight, the Phantom Ray flew to 2,290 meters (7,500 feet) and reached a speed of 178 knots.

The Phantom Ray on the runway preparing for its first flight. Credit: Boeing.

“This day has been two-and-a-half years in the making,” said Darryl Davis, president, Boeing Phantom Works. “It’s the beginning of providing our customers with a test bed to develop future unmanned systems technology, and a testament to the capabilities resident within Boeing. Just as follow-on tests will expand Phantom Ray’s flight envelope, they also will help Boeing expand its presence in the unmanned systems market.”

The flight demonstrated Phantom Ray’s basic airworthiness, and Boeing engineers are planning additional flights in the next few weeks. Other potential uses for the vehicle include intelligence, surveillance and reconnaissance, and suppression of enemy air defenses.

“The first flight moves us farther into the next phase of unmanned aircraft,” said Craig Brown, Phantom Ray program manager for Boeing. “Autonomous, fighter-sized unmanned aircraft are real, and the UAS bar has been raised. Now I’m eager to see how high that bar will go.”

Source: Boeing

Posted on by Nancy Atkinson

SDO: The Moon Gets in My Way

A close-up look at SDO's view of the Moon, backlit by the Sun, showing mountains on the limb. . Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams. Edited by Jason Major. Click for a larger version on Jason's Flickr page.

Early today, the Solar Dynamics Observatory was able to observe the Moon coming in between the spacecraft and the Sun. If you look closely, you can actually see mountains on the Moon subtly backlit by the Sun’s atmosphere.

Cool!

The SDO science team says that not only is this amazing to see, but it actually allows them to “sharpen-up” the SDO images. The sharp edge of the lunar limb allows our team to measure the in-orbit characteristics of the telescopes on board the spacecraft.

See a close-up image (processed by our own Jason Major) below.

[/caption]

Posted on by Nancy Atkinson

Astronaut On Board ISS Gets Word of Mother’s Death

Paolo Nespoli with his mother in November 2010, shortly before he was launched to the International Space Station. Credits: ESA

[/caption]

ISS astronaut Paolo Nespoli from Italy received some sad news while in orbit on the International Space Station: his mother, Maria Motta, has died following an illness. She was 78. This is the second time an ISS astronaut has lost a mother during a long duration mission. U.S. astronaut Daniel Tani’s mother was killed in an accident during the midst of Tani’s ISS expedition in 2007. Nespoli is not scheduled to return to Earth for another three weeks.

Nespoli knew his mother was ill. According to the Associated Press, Nespoli’s family members who live near Milan, Italy have been able to stay in touch with Nespoli with a video system set up in his mother’s home by the European Space Agency. A funeral service will be held on Wednesday, and officials at the European Space Agency said that in such an instance it might be possible to set up a satellite hookup so the absent astronaut could participate in the services.

Just before Nespoli launched on his first mission to space in 2007, his father passed away.

UPDATE: At 15:05 CEST on Wednesday, May 4, the ISS will fly over @Astro_Paolo’s hometown and the crew will observe 1 minute silence. ESA is asking anyone who wishes to participate on their own to please do so.

Anyone interested in expressing their condolences to Paolo can send cards to:

Paolo Nespoli
ESA – European Astronaut Centre
Linder Höhe
D-51147 Cologne
Germany

or on Twitter:
@Astro_Paolo

The STS-134 shuttle will bring Italian astronaut Roberto Vittori to the space station, and Italians were anticipating having two of their countrymen aboard the ISS at once, and plans were in place for Pope Benedict to call the two astronauts while they were in orbit. The technical problems with shuttle Endeavour has caused a delay in the launch, however, with NASA officials saying the shuttle won’t be able to launch any earlier than May 10. Italian officials are hopeful the shuttle won’t be delayed further so that the meetup in space will still be possible.

ESA astronaut Paolo Nespoli works with an experiment on board the International Space Station. Credit: NASA
Posted on by Nancy Atkinson

Hubble Captures Ancient Beauty: M5

A new Hubble image of the Messier 5 cluster. Credit: ESA/Hubble & NASA

[/caption]

This is just plain pretty. You’re looking at some of the oldest stars in the Universe. This new Hubble image of the globular cluster Messier 5 shows this giant huddle of stars, which is one of the oldest clusters in the Milky Way. Astronomers say the majority of M5’s stars formed more than 12 billion years ago. But there are some new and blue stars among the mix, adding some vitality and color to this ancient bunch.

Stars in globular clusters form in the same stellar nursery and grow old together. The most massive stars age quickly, exhausting their fuel supply in less than a million years, and end their lives in spectacular supernovae explosions. This process should have left the ancient cluster Messier 5 with only old, low-mass stars, which, as they have aged and cooled, have become red giants, while the oldest stars have evolved even further into blue horizontal branch stars.

Yet astronomers have spotted many young, blue stars in this cluster, hiding among the much more luminous ancient stars. Astronomers think that these laggard youngsters, called blue stragglers, were created either by stellar collisions or by the transfer of mass between binary stars. Such events are easy to imagine in densely populated globular clusters, in which up to a few million stars are tightly packed together.

Messier 5 lies at a distance of about 25 000 light-years in the constellation of Serpens (The Snake). This image was taken with Wide Field Channel of Hubble’s Advanced Camera for Surveys.

Source: ESA’s Hubble website.

Posted on by Nancy Atkinson

Satellite Imagery Shows How Tornadoes Slashed Across Alabama, Mississippi

This image shows the path of exposed ground left in the wake of an EF5 tornado in Mississippi. Credit: MODIS Rapid Response Team at NASA GSFC.

[/caption]

Some extraordinary satellite and radar imagery shows how the deadly tornado supercell slashed through Alabama and Mississippi last week, as in the image above, leaving a gash of exposed ground and destruction that is visible from space. The latest reports indicate fatalities from the outbreak now exceed 342 people, and according to the Washington Post, this is the most people killed by tornadoes in a two-day period since April 5-6, 1936 when 454 people died. The image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on April 28. See more imagery below.

Part of the path of a 12-mile swath of destruction in Alabama from an EF4 tornado on April 27. Click to see the entire swath taken by a NOAA satellite. Credit: NOAA

The National Weather Service said an EF4, with winds around 175 miles per hour, created a 12-mile-long track of destruction. This tornado caused more than 20 deaths.

Radar sequence of tornado supercell thunderstorms that tracked from western Mississippi into southwest North Carolina. Credit: NCAR, Brian Tang.

This image is pretty amazing: it is a radar montage of the supercell showing some of the 150 tornadoes that were reported on April 27 and 28, 2011. This cell traveled about 450 miles and lasted over 8 hours.

This animation from the NASA Earth Observatory team starts on April 26 and runs through the morning of April 28. It shows a relatively stable mass of cold air—visible as a swirl of more-or-less continuous clouds—rotates in the north along the top of the image, and meanwhile, moist air pushes north and west from the Atlantic Ocean and Gulf of Mexico. The two air masses collide and generate severe weather, but the bad weather also was amplified by the jet stream on April 27, which helped generate the lines of intense thunderstorms and tornadoes.

Sources: NASA Earth Observatory, Washington Post, NOAA